Now Stable

"New on the Web": For a given set of browsers, what APIs became stable and when, ordered reverse chronologically.

It's a great source of information for posts like this

Example Comparisons
Browsers
Features

Stable APIs

Below is a list of features that are in Chrome and Safari, ordered reverse chronologically by when they became stable (i.e, available in the last browser).

2026/2

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Map.getOrInsert 📋Safari12/12/2025 Chrome2/10/202660
javascript.builtins.Map.getOrInsertComputed 📋Safari12/12/2025 Chrome2/10/202660
javascript.builtins.WeakMap.getOrInsert 📋Safari12/12/2025 Chrome2/10/202660
javascript.builtins.WeakMap.getOrInsertComputed 📋Safari12/12/2025 Chrome2/10/202660

2025/9

API First Browser Date Last Browser Date Days Notes
javascript.regular_expressions.modifier 📋Chrome5/14/2024 Safari9/15/2025489
javascript.builtins.Uint8Array.fromBase64 📋Safari12/11/2024 Chrome9/2/2025265
javascript.builtins.Uint8Array.fromHex 📋Safari12/11/2024 Chrome9/2/2025265
javascript.builtins.Uint8Array.setFromBase64 📋Safari12/11/2024 Chrome9/2/2025265
javascript.builtins.Uint8Array.setFromHex 📋Safari12/11/2024 Chrome9/2/2025265
javascript.builtins.Uint8Array.toBase64 📋Safari12/11/2024 Chrome9/2/2025265
javascript.builtins.Uint8Array.toHex 📋Safari12/11/2024 Chrome9/2/2025265

2025/4

API First Browser Date Last Browser Date Days Notes
javascript.builtins.RegExp.escape 📋Safari12/11/2024 Chrome4/29/2025139
javascript.builtins.DataView.getFloat16 📋Safari12/11/2024 Chrome4/1/2025111
javascript.builtins.DataView.setFloat16 📋Safari12/11/2024 Chrome4/1/2025111
javascript.builtins.Float16Array 📋Safari12/11/2024 Chrome4/1/2025111
javascript.builtins.Float16Array.Float16Array 📋Safari12/11/2024 Chrome4/1/2025111
javascript.builtins.Math.f16round 📋Safari12/11/2024 Chrome4/1/2025111

2025/3

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Atomics.pause 📋Chrome2/4/2025 Safari3/31/202555
javascript.builtins.Error.isError 📋Chrome3/4/2025 Safari3/31/202527
Node.js: Returns false for DOMException instances. See issue 56497.Safari: Returns false for DOMException instances.Safari on iOS: Returns false for DOMException instances.WebView on iOS: Returns false for DOMException instances.
javascript.builtins.Iterator.Iterator 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.drop 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.every 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.filter 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.find 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.flatMap 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.forEach 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.from 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.map 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.reduce 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.some 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.take 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.Iterator.toArray 📋Chrome2/20/2024 Safari3/31/2025405
javascript.builtins.JSON.parse.reviver_parameter_context_argument 📋Chrome5/30/2023 Safari3/31/2025671

2024/12

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Promise.try 📋Chrome8/20/2024 Safari12/11/2024113

2024/10

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Intl.Locale.getCalendars 📋Safari9/18/2023 Chrome10/15/2024393
Chrome: Implemented as an accessor property.Chrome Android: Implemented as an accessor property.Edge: Implemented as an accessor property.Node.js: Implemented as an accessor property.Quest Browser: Implemented as an accessor property.Opera: Implemented as an accessor property.Opera Android: Implemented as an accessor property.Safari: Implemented as an accessor property.Safari on iOS: Implemented as an accessor property.Samsung Internet: Implemented as an accessor property.WebView Android: Implemented as an accessor property.WebView on iOS: Implemented as an accessor property.
javascript.builtins.Intl.Locale.getCollations 📋Safari9/18/2023 Chrome10/15/2024393
Chrome: Implemented as an accessor property.Chrome Android: Implemented as an accessor property.Edge: Implemented as an accessor property.Node.js: Implemented as an accessor property.Quest Browser: Implemented as an accessor property.Opera: Implemented as an accessor property.Opera Android: Implemented as an accessor property.Safari: Implemented as an accessor property.Safari on iOS: Implemented as an accessor property.Samsung Internet: Implemented as an accessor property.WebView Android: Implemented as an accessor property.WebView on iOS: Implemented as an accessor property.
javascript.builtins.Intl.Locale.getHourCycles 📋Safari9/18/2023 Chrome10/15/2024393
Chrome: Implemented as an accessor property.Chrome Android: Implemented as an accessor property.Edge: Implemented as an accessor property.Node.js: Implemented as an accessor property.Quest Browser: Implemented as an accessor property.Opera: Implemented as an accessor property.Opera Android: Implemented as an accessor property.Safari: Implemented as an accessor property.Safari on iOS: Implemented as an accessor property.Samsung Internet: Implemented as an accessor property.WebView Android: Implemented as an accessor property.WebView on iOS: Implemented as an accessor property.
javascript.builtins.Intl.Locale.getNumberingSystems 📋Safari9/18/2023 Chrome10/15/2024393
Chrome: Implemented as an accessor property.Chrome Android: Implemented as an accessor property.Edge: Implemented as an accessor property.Node.js: Implemented as an accessor property.Quest Browser: Implemented as an accessor property.Opera: Implemented as an accessor property.Opera Android: Implemented as an accessor property.Safari: Implemented as an accessor property.Safari on iOS: Implemented as an accessor property.Samsung Internet: Implemented as an accessor property.WebView Android: Implemented as an accessor property.WebView on iOS: Implemented as an accessor property.
javascript.builtins.Intl.Locale.getTextInfo 📋Safari9/18/2023 Chrome10/15/2024393
Chrome: Implemented as an accessor property.Chrome Android: Implemented as an accessor property.Deno: Implemented as an accessor property.Edge: Implemented as an accessor property.Node.js: Implemented as an accessor property.Quest Browser: Implemented as an accessor property.Opera: Implemented as an accessor property.Opera Android: Implemented as an accessor property.Safari: Implemented as an accessor property.Safari on iOS: Implemented as an accessor property.Samsung Internet: Implemented as an accessor property.WebView Android: Implemented as an accessor property.WebView on iOS: Implemented as an accessor property.
javascript.builtins.Intl.Locale.getTimeZones 📋Safari9/18/2023 Chrome10/15/2024393
Chrome: Implemented as an accessor property.Chrome Android: Implemented as an accessor property.Edge: Implemented as an accessor property.Node.js: Implemented as an accessor property.Quest Browser: Implemented as an accessor property.Opera: Implemented as an accessor property.Opera Android: Implemented as an accessor property.Safari: Implemented as an accessor property.Safari on iOS: Implemented as an accessor property.Samsung Internet: Implemented as an accessor property.WebView Android: Implemented as an accessor property.WebView on iOS: Implemented as an accessor property.
javascript.builtins.Intl.Locale.getWeekInfo 📋Safari9/18/2023 Chrome10/15/2024393
Chrome: Implemented as an accessor property.Chrome Android: Implemented as an accessor property.Deno: Implemented as an accessor property.Edge: Implemented as an accessor property.Node.js: Implemented as an accessor property.Quest Browser: Implemented as an accessor property.Opera: Implemented as an accessor property.Opera Android: Implemented as an accessor property.Safari: Implemented as an accessor property.Safari on iOS: Implemented as an accessor property.Samsung Internet: Implemented as an accessor property.WebView Android: Implemented as an accessor property.WebView on iOS: Implemented as an accessor property.

2024/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Intl.DurationFormat 📋Safari3/27/2023 Chrome9/17/2024540
javascript.builtins.Intl.DurationFormat.DurationFormat 📋Safari3/27/2023 Chrome9/17/2024540
javascript.builtins.Intl.DurationFormat.format 📋Safari3/27/2023 Chrome9/17/2024540
javascript.builtins.Intl.DurationFormat.formatToParts 📋Safari3/27/2023 Chrome9/17/2024540
javascript.builtins.Intl.DurationFormat.resolvedOptions 📋Safari3/27/2023 Chrome9/17/2024540
javascript.builtins.Intl.DurationFormat.supportedLocalesOf 📋Safari3/27/2023 Chrome9/17/2024540

2024/5

API First Browser Date Last Browser Date Days Notes
javascript.regular_expressions.named_capturing_group.duplicate_named_capturing_groups Safari9/18/2023 Chrome5/14/2024239

2024/3

API First Browser Date Last Browser Date Days Notes
javascript.statements.import.import_attributes 📋Safari12/11/2023 Chrome3/19/202499
javascript.statements.import.import_attributes.type_json Safari12/11/2023 Chrome3/19/202499
javascript.builtins.ArrayBuffer.detached 📋Chrome5/30/2023 Safari3/5/2024280
javascript.builtins.ArrayBuffer.transfer 📋Chrome5/30/2023 Safari3/5/2024280
javascript.builtins.ArrayBuffer.transferToFixedLength 📋Chrome5/30/2023 Safari3/5/2024280
javascript.builtins.Map.groupBy 📋Chrome9/12/2023 Safari3/5/2024175
javascript.builtins.Object.groupBy 📋Chrome9/12/2023 Safari3/5/2024175
javascript.builtins.Promise.withResolvers 📋Chrome10/31/2023 Safari3/5/2024126

2024/2

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Set.difference 📋Safari9/18/2023 Chrome2/20/2024155
javascript.builtins.Set.intersection 📋Safari9/18/2023 Chrome2/20/2024155
javascript.builtins.Set.isDisjointFrom 📋Safari9/18/2023 Chrome2/20/2024155
javascript.builtins.Set.isSubsetOf 📋Safari9/18/2023 Chrome2/20/2024155
javascript.builtins.Set.isSupersetOf 📋Safari9/18/2023 Chrome2/20/2024155
javascript.builtins.Set.symmetricDifference 📋Safari9/18/2023 Chrome2/20/2024155
javascript.builtins.Set.union 📋Safari9/18/2023 Chrome2/20/2024155

2024/1

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.fromAsync 📋Safari3/27/2023 Chrome1/23/2024302

2023/12

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Error.captureStackTrace 📋Chrome9/15/2009 Safari12/11/20235200
javascript.builtins.Intl.PluralRules.PluralRules.options_parameter.options_roundingMode_parameter Chrome9/12/2023 Safari12/11/202390

2023/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.AggregateError.serializable_object Chrome2/1/2022 Safari9/18/2023594
Chrome: AggregateError serializes to the Error type, without additional properties.Chrome Android: AggregateError serializes to the Error type, without additional properties.Edge: AggregateError serializes to the Error type, without additional properties.Firefox: AggregateError serializes to the AggregateError type, with properties name, message, cause, and errors.Firefox for Android: AggregateError serializes to the AggregateError type, with properties name, message, cause, and errors.Quest Browser: AggregateError serializes to the Error type, without additional properties.Opera: AggregateError serializes to the Error type, without additional properties.Opera Android: AggregateError serializes to the Error type, without additional properties.Samsung Internet: AggregateError serializes to the Error type, without additional properties.WebView Android: AggregateError serializes to the Error type, without additional properties.
javascript.builtins.Function.toString.toString_revision Chrome4/17/2018 Safari9/18/20231980
javascript.builtins.RegExp.unicodeSets 📋Chrome4/4/2023 Safari9/18/2023167

2023/3

API First Browser Date Last Browser Date Days Notes
javascript.builtins.ArrayBuffer.ArrayBuffer.maxByteLength_option 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.ArrayBuffer.maxByteLength 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.ArrayBuffer.resizable 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.ArrayBuffer.resize 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.Atomics.waitAsync 📋Chrome4/13/2021 Safari3/27/2023713
Chrome: The Atomics.waitAsync() method never times out. See bug 40742782.Chrome Android: The Atomics.waitAsync() method never times out. See bug 40742782.Edge: The Atomics.waitAsync() method never times out. See bug 40742782.Quest Browser: The Atomics.waitAsync() method never times out. See bug 40742782.Opera Android: The Atomics.waitAsync() method never times out. See bug 40742782.WebView Android: The Atomics.waitAsync() method never times out. See bug 40742782.
javascript.builtins.FinalizationRegistry.register.symbol_as_target Chrome1/10/2023 Safari3/27/202376
javascript.builtins.FinalizationRegistry.unregister.symbol_as_target Chrome1/10/2023 Safari3/27/202376
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_useGrouping_parameter.string_values Chrome9/27/2022 Safari3/27/2023181
javascript.builtins.SharedArrayBuffer.SharedArrayBuffer.maxByteLength_option 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.SharedArrayBuffer.grow 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.SharedArrayBuffer.growable 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.SharedArrayBuffer.maxByteLength 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.String.isWellFormed 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.String.toWellFormed 📋Chrome3/7/2023 Safari3/27/202320
javascript.builtins.WeakMap.symbol_as_keys Chrome1/10/2023 Safari3/27/202376
javascript.builtins.WeakRef.WeakRef.symbol_as_target Chrome1/10/2023 Safari3/27/202376
javascript.builtins.WeakSet.symbol_as_keys Chrome1/10/2023 Safari3/27/202376
javascript.classes.static.initialization_blocks 📋Chrome9/21/2021 Safari3/27/2023552
javascript.operators.import_meta.resolve 📋Chrome9/2/2022 Safari3/27/2023206
Node.js: Returns a URL object instead of a string.
javascript.regular_expressions.lookbehind_assertion 📋Chrome10/17/2017 Safari3/27/20231987

2023/2

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.toReversed 📋Safari9/12/2022 Chrome2/7/2023148
javascript.builtins.Array.toSorted 📋Safari9/12/2022 Chrome2/7/2023148
javascript.builtins.Array.toSpliced 📋Safari9/12/2022 Chrome2/7/2023148
javascript.builtins.Array.with 📋Safari9/12/2022 Chrome2/7/2023148
javascript.builtins.TypedArray.toReversed 📋Safari9/12/2022 Chrome2/7/2023148
javascript.builtins.TypedArray.toSorted 📋Safari9/12/2022 Chrome2/7/2023148
javascript.builtins.TypedArray.with 📋Safari9/12/2022 Chrome2/7/2023148

2022/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_roundingIncrement_parameter Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_roundingMode_parameter Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_roundingPriority_parameter Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_signDisplay_parameter.negative Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_trailingZeroDisplay_parameter Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.NumberFormat.format.number_parameter-string_decimal Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.NumberFormat.formatRange 📋Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.NumberFormat.formatRangeToParts 📋Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.PluralRules.PluralRules.options_parameter Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.PluralRules.PluralRules.options_parameter.options_roundingPriority_parameter Safari3/14/2022 Chrome9/27/2022197
javascript.builtins.Intl.PluralRules.selectRange 📋Safari3/14/2022 Chrome9/27/2022197
javascript.classes.public_class_fields 📋Chrome1/29/2019 Safari9/12/20221322
Safari: Parentheses in field initializers can lead to ReferenceErrors. See bug 236843.Safari: Doesn't support public static fields. See bug 194095.Safari on iOS: Parentheses in field initializers can lead to ReferenceErrors. See bug 236843.Safari on iOS: Doesn't support public static fields. See bug 194095.WebView on iOS: Parentheses in field initializers can lead to ReferenceErrors. See bug 236843.WebView on iOS: Doesn't support public static fields. See bug 194095.

2022/3

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.at 📋Chrome7/20/2021 Safari3/14/2022237
javascript.builtins.Array.findLast 📋Chrome1/4/2022 Safari3/14/202269
javascript.builtins.Array.findLastIndex 📋Chrome1/4/2022 Safari3/14/202269
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_timeZoneName_parameter.extended_values Chrome10/19/2021 Safari3/14/2022146
javascript.builtins.Intl.supportedValuesOf 📋Chrome3/1/2022 Safari3/14/202213
javascript.builtins.Intl.supportedValuesOf.key_parameter_calendar Chrome3/1/2022 Safari3/14/202213
javascript.builtins.Intl.supportedValuesOf.key_parameter_collation Chrome3/1/2022 Safari3/14/202213
javascript.builtins.Intl.supportedValuesOf.key_parameter_currency Chrome3/1/2022 Safari3/14/202213
javascript.builtins.Intl.supportedValuesOf.key_parameter_numberingSystem Chrome3/1/2022 Safari3/14/202213
javascript.builtins.Intl.supportedValuesOf.key_parameter_timeZone Chrome3/1/2022 Safari3/14/202213
javascript.builtins.Intl.supportedValuesOf.key_parameter_unit Chrome3/1/2022 Safari3/14/202213
javascript.builtins.Object.hasOwn 📋Chrome8/31/2021 Safari3/14/2022195
javascript.builtins.String.at 📋Chrome7/20/2021 Safari3/14/2022237
javascript.builtins.TypedArray.at 📋Chrome7/20/2021 Safari3/14/2022237
javascript.builtins.TypedArray.findLast 📋Chrome1/4/2022 Safari3/14/202269
javascript.builtins.TypedArray.findLastIndex 📋Chrome1/4/2022 Safari3/14/202269

2021/12

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Atomics 📋Chrome7/24/2018 Safari12/13/20211238
Safari: Before Safari 16.4, Atomics is gated behind COOP/COEP. For more detail, read Making your website "cross-origin isolated" using COOP and COEP.Safari on iOS: Before Safari on iOS 16.4, Atomics is gated behind COOP/COEP. For more detail, read Making your website "cross-origin isolated" using COOP and COEP.WebView on iOS: Before WebView on iOS 16.4, Atomics is gated behind COOP/COEP. For more detail, read Making your website "cross-origin isolated" using COOP and COEP.
javascript.builtins.Atomics.add 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.and 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.compareExchange 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.exchange 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.isLockFree 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.load 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.notify 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.or 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.store 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.sub 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.wait 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.Atomics.xor 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.DataView.DataView.sharedarraybuffer_support Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.SharedArrayBuffer 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.SharedArrayBuffer.@@species 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.SharedArrayBuffer.SharedArrayBuffer 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.SharedArrayBuffer.byteLength 📋Chrome7/24/2018 Safari12/13/20211238
javascript.builtins.SharedArrayBuffer.slice 📋Chrome7/24/2018 Safari12/13/20211238

2021/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.BigInt64Array 📋Chrome5/29/2018 Safari9/20/20211210
javascript.builtins.BigInt64Array.BigInt64Array 📋Chrome5/29/2018 Safari9/20/20211210
javascript.builtins.BigUint64Array 📋Chrome5/29/2018 Safari9/20/20211210
javascript.builtins.BigUint64Array.BigUint64Array 📋Chrome5/29/2018 Safari9/20/20211210
javascript.builtins.DataView.getBigInt64 📋Chrome5/29/2018 Safari9/20/20211210
javascript.builtins.DataView.getBigUint64 📋Chrome5/29/2018 Safari9/20/20211210
javascript.builtins.DataView.setBigInt64 📋Chrome5/29/2018 Safari9/20/20211210
javascript.builtins.DataView.setBigUint64 📋Chrome5/29/2018 Safari9/20/20211210
javascript.builtins.Error.Error.options_cause_parameter 📋Chrome8/31/2021 Safari9/20/202120
javascript.builtins.Error.cause 📋Chrome8/31/2021 Safari9/20/202120
Chrome: Before version 125, default console logging for Error objects does not print the cause.Chrome Android: Before version 125, default console logging for Error objects does not print the cause.Edge: Before version 125, default console logging for Error objects does not print the cause.Quest Browser: Before version false, default console logging for Error objects does not print the cause.Opera: Before version 111, default console logging for Error objects does not print the cause.Opera Android: Before version 83, default console logging for Error objects does not print the cause.Safari: Default console logging for Error objects does not print the cause.Safari on iOS: Default console logging for Error objects does not print the cause.Samsung Internet: Before version 27.0, default console logging for Error objects does not print the cause.WebView Android: Before version 125, default console logging for Error objects does not print the cause.WebView on iOS: Default console logging for Error objects does not print the cause.
javascript.builtins.RegExp.hasIndices 📋Chrome4/13/2021 Safari9/20/2021160
javascript.classes.private_class_fields_in 📋Chrome5/25/2021 Safari9/20/2021118
javascript.classes.private_class_methods 📋Chrome7/27/2020 Safari9/20/2021420
javascript.grammar.trailing_commas.trailing_commas_in_dynamic_import 📋Chrome5/25/2021 Safari9/20/2021118
Node.js: The second parameter no longer throws a parser error, but the --experimental-json-modules flag is still needed to load JSON modules.
javascript.operators.await.top_level 📋Chrome3/2/2021 Safari9/20/2021202
Node.js: Not supported in CommonJS modules.Safari: Doesn't support multiple modules simultaneously importing a module containing a top-level await (see bug 242740).Safari on iOS: Doesn't support multiple modules simultaneously importing a module containing a top-level await (see bug 242740).WebView on iOS: Doesn't support multiple modules simultaneously importing a module containing a top-level await (see bug 242740).
javascript.operators.import.options_parameter 📋Chrome5/25/2021 Safari9/20/2021118
Node.js: The second parameter no longer throws a parser error, but the --experimental-json-modules flag is still needed to load JSON modules.
javascript.operators.import.worker_support Chrome2/4/2020 Safari9/20/2021594
javascript.statements.import.service_worker_support Chrome5/25/2021 Safari9/20/2021118
javascript.statements.import.worker_support Chrome2/4/2020 Safari9/20/2021594

2021/7

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_dayPeriod_parameter Safari4/26/2021 Chrome7/20/202185

2021/5

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.IntlLegacyConstructedSymbol 📋Safari4/26/2021 Chrome5/25/202129
Chrome: The fallback symbol property has description IntlFallback.Chrome Android: The fallback symbol property has description IntlFallback.Edge: The fallback symbol property has description IntlFallback.Node.js: The fallback symbol property has description IntlFallback.Quest Browser: The fallback symbol property has description IntlFallback.Opera: The fallback symbol property has description IntlFallback.Opera Android: The fallback symbol property has description IntlFallback.Samsung Internet: The fallback symbol property has description IntlFallback.WebView Android: The fallback symbol property has description IntlFallback.
javascript.builtins.Intl.NumberFormat.NumberFormat.IntlLegacyConstructedSymbol 📋Safari4/26/2021 Chrome5/25/202129
Chrome: The fallback symbol property has description IntlFallback.Chrome Android: The fallback symbol property has description IntlFallback.Edge: The fallback symbol property has description IntlFallback.Node.js: The fallback symbol property has description IntlFallback.Quest Browser: The fallback symbol property has description IntlFallback.Opera: The fallback symbol property has description IntlFallback.Opera Android: The fallback symbol property has description IntlFallback.Samsung Internet: The fallback symbol property has description IntlFallback.WebView Android: The fallback symbol property has description IntlFallback.

2021/4

API First Browser Date Last Browser Date Days Notes
javascript.builtins.FinalizationRegistry 📋Chrome7/27/2020 Safari4/26/2021273
javascript.builtins.FinalizationRegistry.FinalizationRegistry 📋Chrome7/27/2020 Safari4/26/2021273
javascript.builtins.FinalizationRegistry.register 📋Chrome7/27/2020 Safari4/26/2021273
javascript.builtins.FinalizationRegistry.unregister 📋Chrome7/27/2020 Safari4/26/2021273
javascript.builtins.Intl.Collator.Collator.options_collation_parameter Chrome10/20/2020 Safari4/26/2021188
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_calendar_parameter Chrome2/4/2020 Safari4/26/2021447
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_dateStyle_parameter Chrome7/30/2019 Safari4/26/2021636
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_fractionalSecondDigits_parameter Chrome7/27/2020 Safari4/26/2021273
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_numberingSystem_parameter Chrome2/4/2020 Safari4/26/2021447
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_timeStyle_parameter Chrome7/30/2019 Safari4/26/2021636
javascript.builtins.Intl.DateTimeFormat.formatRange 📋Chrome7/30/2019 Safari4/26/2021636
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the DateTimeFormat() constructor for more details.
javascript.builtins.Intl.DateTimeFormat.formatRangeToParts 📋Chrome7/30/2019 Safari4/26/2021636
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the DateTimeFormat() constructor for more details.
javascript.builtins.Intl.DisplayNames 📋Chrome4/7/2020 Safari4/26/2021384
javascript.builtins.Intl.DisplayNames.DisplayNames 📋Chrome4/7/2020 Safari4/26/2021384
javascript.builtins.Intl.DisplayNames.of 📋Chrome4/7/2020 Safari4/26/2021384
javascript.builtins.Intl.DisplayNames.resolvedOptions 📋Chrome4/7/2020 Safari4/26/2021384
javascript.builtins.Intl.DisplayNames.supportedLocalesOf 📋Chrome4/7/2020 Safari4/26/2021384
javascript.builtins.Intl.ListFormat 📋Chrome1/29/2019 Safari4/26/2021818
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the ListFormat() constructor for more details.Safari: Only available on macOS Big Sur (11) and above.
javascript.builtins.Intl.ListFormat.ListFormat 📋Chrome1/29/2019 Safari4/26/2021818
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the ListFormat instance silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.Safari: Only available on macOS Big Sur (11) and above.
javascript.builtins.Intl.ListFormat.format 📋Chrome1/29/2019 Safari4/26/2021818
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the ListFormat() constructor for more details.Safari: Only available on macOS Big Sur (11) and above.
javascript.builtins.Intl.ListFormat.formatToParts 📋Chrome1/29/2019 Safari4/26/2021818
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the ListFormat() constructor for more details.Safari: Only available on macOS Big Sur (11) and above.
javascript.builtins.Intl.ListFormat.resolvedOptions 📋Chrome1/29/2019 Safari4/26/2021818
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the ListFormat() constructor for more details.Safari: Only available on macOS Big Sur (11) and above.
javascript.builtins.Intl.ListFormat.supportedLocalesOf 📋Chrome1/29/2019 Safari4/26/2021818
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.Safari: Only available on macOS Big Sur (11) and above.
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_compactDisplay_parameter Chrome9/10/2019 Safari4/26/2021594
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_currencyDisplay_parameter Chrome9/10/2019 Safari4/26/2021594
Safari: Doesn't support currencyDisplay: 'narrowSymbol'.Safari on iOS: Doesn't support currencyDisplay: 'narrowSymbol'.WebView on iOS: Doesn't support currencyDisplay: 'narrowSymbol'.
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_currencySign_parameter Chrome9/10/2019 Safari4/26/2021594
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_notation_parameter Chrome9/10/2019 Safari4/26/2021594
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_numberingSystem_parameter Chrome1/10/2013 Safari4/26/20213028
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_signDisplay_parameter Chrome9/10/2019 Safari4/26/2021594
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_unitDisplay_parameter Chrome9/10/2019 Safari4/26/2021594
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_unit_parameter Chrome9/10/2019 Safari4/26/2021594
javascript.builtins.Intl.Segmenter 📋Chrome11/17/2020 Safari4/26/2021160
javascript.builtins.Intl.Segmenter.Segmenter 📋Chrome11/17/2020 Safari4/26/2021160
javascript.builtins.Intl.Segmenter.resolvedOptions 📋Chrome11/17/2020 Safari4/26/2021160
javascript.builtins.Intl.Segmenter.segment 📋Chrome11/17/2020 Safari4/26/2021160
javascript.builtins.Intl.Segmenter.supportedLocalesOf 📋Chrome11/17/2020 Safari4/26/2021160
javascript.builtins.Intl.Segments 📋Chrome11/17/2020 Safari4/26/2021160
javascript.builtins.Intl.Segments.@@iterator 📋Chrome11/17/2020 Safari4/26/2021160
javascript.builtins.Intl.Segments.containing 📋Chrome11/17/2020 Safari4/26/2021160
javascript.builtins.WeakRef 📋Chrome7/27/2020 Safari4/26/2021273
javascript.builtins.WeakRef.WeakRef 📋Chrome7/27/2020 Safari4/26/2021273
javascript.builtins.WeakRef.deref 📋Chrome7/27/2020 Safari4/26/2021273
javascript.classes.private_class_fields 📋Chrome4/23/2019 Safari4/26/2021734
javascript.classes.static.class_fields 📋Chrome1/29/2019 Safari4/26/2021818
javascript.statements.export.arbitrary_module_namespace_identifier_names Chrome1/19/2021 Safari4/26/202197
javascript.statements.export.namespace 📋Chrome1/29/2019 Safari4/26/2021818
Node.js: Modules must either have a filename ending in .mjs, or the nearest parent package.json file must contain "type": "module". See Node's ECMAScript Modules documentation for more details.
javascript.statements.import.arbitrary_module_namespace_identifier_names Chrome1/19/2021 Safari4/26/202197

2020/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.AggregateError 📋Chrome8/25/2020 Safari9/16/202022
javascript.builtins.AggregateError.AggregateError 📋Chrome8/25/2020 Safari9/16/202022
javascript.builtins.AggregateError.errors 📋Chrome8/25/2020 Safari9/16/202022
javascript.builtins.BigInt 📋Chrome5/29/2018 Safari9/16/2020841
javascript.builtins.BigInt.BigInt 📋Chrome5/29/2018 Safari9/16/2020841
javascript.builtins.BigInt.asIntN 📋Chrome5/29/2018 Safari9/16/2020841
javascript.builtins.BigInt.asUintN 📋Chrome5/29/2018 Safari9/16/2020841
javascript.builtins.BigInt.toLocaleString 📋Chrome5/29/2018 Safari9/16/2020841
javascript.builtins.BigInt.toLocaleString.locales_parameter Chrome7/30/2019 Safari9/16/2020414
Deno: Only the locale data for en-US is available.
javascript.builtins.BigInt.toLocaleString.options_parameter Chrome7/30/2019 Safari9/16/2020414
javascript.builtins.BigInt.toString 📋Chrome5/29/2018 Safari9/16/2020841
javascript.builtins.BigInt.valueOf 📋Chrome5/29/2018 Safari9/16/2020841
javascript.builtins.Intl.Locale 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.Locale 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.baseName 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.calendar 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.caseFirst 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.collation 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.hourCycle 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.language 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.maximize 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.minimize 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.numberingSystem 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.numeric 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.region 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.script 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.Locale.toString 📋Chrome4/23/2019 Safari9/16/2020512
javascript.builtins.Intl.RelativeTimeFormat 📋Chrome12/4/2018 Safari9/16/2020652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the RelativeTimeFormat() constructor for more details.
javascript.builtins.Intl.RelativeTimeFormat.RelativeTimeFormat 📋Chrome12/4/2018 Safari9/16/2020652
javascript.builtins.Intl.RelativeTimeFormat.RelativeTimeFormat.locales_parameter Chrome12/4/2018 Safari9/16/2020652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the RelativeTimeFormat instance silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.RelativeTimeFormat.RelativeTimeFormat.options_parameter.options_localeMatcher_parameter Chrome12/4/2018 Safari9/16/2020652
javascript.builtins.Intl.RelativeTimeFormat.RelativeTimeFormat.options_parameter.options_numberingSystem_parameter Chrome12/4/2018 Safari9/16/2020652
javascript.builtins.Intl.RelativeTimeFormat.RelativeTimeFormat.options_parameter.options_numeric_parameter Chrome12/4/2018 Safari9/16/2020652
javascript.builtins.Intl.RelativeTimeFormat.format 📋Chrome12/4/2018 Safari9/16/2020652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the RelativeTimeFormat() constructor for more details.
javascript.builtins.Intl.RelativeTimeFormat.formatToParts 📋Chrome12/4/2018 Safari9/16/2020652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the RelativeTimeFormat() constructor for more details.
javascript.builtins.Intl.RelativeTimeFormat.resolvedOptions 📋Chrome12/4/2018 Safari9/16/2020652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the RelativeTimeFormat() constructor for more details.
javascript.builtins.Intl.RelativeTimeFormat.supportedLocalesOf 📋Chrome12/4/2018 Safari9/16/2020652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Promise.any 📋Chrome8/25/2020 Safari9/16/202022
javascript.builtins.Symbol.toStringTag.dom_objects Chrome4/13/2016 Safari9/16/20201617
javascript.operators.logical_and_assignment 📋Chrome8/25/2020 Safari9/16/202022
javascript.operators.logical_or_assignment 📋Chrome8/25/2020 Safari9/16/202022
javascript.operators.nullish_coalescing_assignment 📋Chrome8/25/2020 Safari9/16/202022

2020/8

API First Browser Date Last Browser Date Days Notes
javascript.builtins.String.replaceAll 📋Safari3/24/2020 Chrome8/25/2020154

2020/3

API First Browser Date Last Browser Date Days Notes
javascript.grammar.hashbang_comments 📋Chrome4/23/2019 Safari3/24/2020336
javascript.operators.nullish_coalescing 📋Chrome2/4/2020 Safari3/24/202049
javascript.operators.optional_chaining 📋Chrome2/4/2020 Safari3/24/202049

2019/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_hourCycle_parameter Chrome3/12/2019 Safari9/19/2019191
javascript.builtins.Intl.NumberFormat.formatToParts 📋Chrome1/23/2018 Safari9/19/2019604
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the NumberFormat() constructor for more details.
javascript.builtins.Intl.PluralRules 📋Chrome12/6/2017 Safari9/19/2019652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the PluralRules() constructor for more details.
javascript.builtins.Intl.PluralRules.PluralRules 📋Chrome12/6/2017 Safari9/19/2019652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the PluralRules instance silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.PluralRules.resolvedOptions 📋Chrome12/6/2017 Safari9/19/2019652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the PluralRules() constructor for more details.
javascript.builtins.Intl.PluralRules.select 📋Chrome12/6/2017 Safari9/19/2019652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the PluralRules() constructor for more details.
javascript.builtins.Intl.PluralRules.supportedLocalesOf 📋Chrome12/6/2017 Safari9/19/2019652
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the PluralRules() constructor for more details.
javascript.builtins.Promise.allSettled 📋Chrome7/30/2019 Safari9/19/201951
javascript.builtins.RegExp.@@matchAll 📋Chrome3/12/2019 Safari9/19/2019191
javascript.builtins.String.matchAll 📋Chrome3/12/2019 Safari9/19/2019191
javascript.builtins.Symbol.matchAll 📋Chrome3/12/2019 Safari9/19/2019191
javascript.grammar.numeric_separators 📋Chrome6/4/2019 Safari9/19/2019107

2019/3

API First Browser Date Last Browser Date Days Notes
javascript.builtins.JSON.stringify.well_formed_stringify Chrome1/29/2019 Safari3/25/201955
javascript.builtins.Object.fromEntries 📋Chrome3/12/2019 Safari3/25/201913
javascript.builtins.Symbol.description 📋Chrome10/16/2018 Safari3/25/2019160
Safari: No support for an undefined description.Safari on iOS: No support for an undefined description.WebView on iOS: No support for an undefined description.
javascript.builtins.globalThis 📋Chrome12/4/2018 Safari3/25/2019111
javascript.builtins.RegExp.source.escaping Safari7/25/2012 Chrome3/12/20192421
javascript.builtins.RegExp.toString.escaping Safari7/25/2012 Chrome3/12/20192421

2018/10

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.sort.stable_sorting Safari3/27/2017 Chrome10/16/2018568

2018/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.flat 📋Chrome9/4/2018 Safari9/17/201813
javascript.builtins.Array.flatMap 📋Chrome9/4/2018 Safari9/17/201813
javascript.builtins.AsyncGenerator 📋Chrome12/6/2017 Safari9/17/2018285
javascript.builtins.AsyncGenerator.next 📋Chrome12/6/2017 Safari9/17/2018285
javascript.builtins.AsyncGenerator.return 📋Chrome12/6/2017 Safari9/17/2018285
javascript.builtins.AsyncGenerator.throw 📋Chrome12/6/2017 Safari9/17/2018285
javascript.builtins.AsyncGeneratorFunction 📋Chrome12/6/2017 Safari9/17/2018285
javascript.builtins.AsyncGeneratorFunction.AsyncGeneratorFunction 📋Chrome12/6/2017 Safari9/17/2018285
javascript.builtins.JSON.json_superset Chrome4/17/2018 Safari9/17/2018153
javascript.builtins.String.trimEnd 📋Chrome4/17/2018 Safari9/17/2018153
javascript.builtins.String.trimStart 📋Chrome4/17/2018 Safari9/17/2018153
javascript.functions.method_definitions.async_generator_methods Chrome12/6/2017 Safari9/17/2018285
javascript.operators.async_generator_function 📋Chrome12/6/2017 Safari9/17/2018285
javascript.statements.async_generator_function 📋Chrome12/6/2017 Safari9/17/2018285
javascript.statements.for_await_of 📋Chrome12/6/2017 Safari9/17/2018285

2018/4

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.values 📋Safari9/30/2015 Chrome4/17/2018930
javascript.statements.try_catch.optional_catch_binding Safari4/12/2018 Chrome4/17/20185
javascript.builtins.AsyncIterator 📋Chrome12/6/2017 Safari4/12/2018127
javascript.builtins.AsyncIterator.@@asyncIterator 📋Chrome12/6/2017 Safari4/12/2018127
javascript.builtins.Error.stackTraceLimit Chrome9/15/2009 Safari4/12/20183131
javascript.builtins.Promise.finally 📋Chrome12/6/2017 Safari4/12/2018127
javascript.builtins.RegExp.dotAll 📋Chrome10/17/2017 Safari4/12/2018177
javascript.builtins.Symbol.asyncIterator 📋Chrome12/6/2017 Safari4/12/2018127
javascript.operators.destructuring.rest_in_objects Chrome7/25/2017 Safari4/12/2018261
javascript.operators.import 📋Chrome12/6/2017 Safari4/12/2018127
Deno: Bundled Deno applications (using deno compile) do not support dynamic importsNode.js: Dynamic import can be used in either CommonJS or ES module files, to import either CommonJS or ES module files. See Node's ECMAScript Modules documentation for more details.Node.js: Dynamic import can be used in either CommonJS or ES module files, to import either CommonJS or ES module files. See Node's ECMAScript Modules documentation for more details.
javascript.operators.import_meta 📋Chrome1/23/2018 Safari4/12/201879
javascript.operators.object_initializer.spread_properties Chrome7/25/2017 Safari4/12/2018261
javascript.operators.spread.spread_in_object_literals 📋Chrome7/25/2017 Safari4/12/2018261
javascript.regular_expressions.named_backreference 📋Chrome1/23/2018 Safari4/12/201879
javascript.regular_expressions.named_capturing_group 📋Chrome1/23/2018 Safari4/12/201879
javascript.regular_expressions.unicode_character_class_escape 📋Chrome1/23/2018 Safari4/12/201879

2017/12

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Proxy.revocable 📋Safari9/20/2016 Chrome12/6/2017442
javascript.statements.for_of.async_iterators Safari10/22/2013 Chrome12/6/20171506

2017/10

API First Browser Date Last Browser Date Days Notes
javascript.grammar.template_literals.template_literal_revision Safari9/19/2017 Chrome10/17/201728

2017/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Intl.Collator.Collator.options_caseFirst_parameter Chrome1/10/2013 Safari9/19/20171713
javascript.builtins.Intl.DateTimeFormat.formatToParts 📋Chrome3/9/2017 Safari9/19/2017194
Chrome: Before version 71, formatToParts() returned an object with an incorrectly cased type key of dayperiod. Version 71 and later use the specification defined dayPeriod. See bug 41402623.Chrome Android: Before version 71, formatToParts() returned an object with an incorrectly cased type key of dayperiod. Version 71 and later use the specification defined dayPeriod. See bug 41402623.Node.js: Before version 12.0.0, formatToParts() returned an object with an incorrectly cased type key of dayperiod. Version 12.0.0 and later use the specification defined dayPeriod. See bug 41402623.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the DateTimeFormat() constructor for more details.Quest Browser: Before version 6.0, formatToParts() returned an object with an incorrectly cased type key of dayperiod. Version 71 and later use the specification defined dayPeriod. See bug 41402623.Opera: Before version 58, formatToParts() returned an object with an incorrectly cased type key of dayperiod. Version 58 and later use the specification defined dayPeriod. See bug 41402623.Opera Android: Before version 50, formatToParts() returned an object with an incorrectly cased type key of dayperiod. Version 50 and later use the specification defined dayPeriod. See bug 41402623.Samsung Internet: Before version 71, formatToParts() returned an object with an incorrectly cased type key of dayperiod. Version 71 and later use the specification defined dayPeriod. See bug 41402623.WebView Android: Before version 71, formatToParts() returned an object with an incorrectly cased type key of dayperiod. Version 71 and later use the specification defined dayPeriod. See bug 41402623.
javascript.operators.new_target 📋Chrome10/13/2015 Safari9/19/2017707
javascript.statements.export 📋Safari3/27/2017 Chrome9/5/2017162
Node.js: Modules must either have a filename ending in .mjs, or the nearest parent package.json file must contain "type": "module". See Node's ECMAScript Modules documentation for more details.
javascript.statements.export.default 📋Safari3/27/2017 Chrome9/5/2017162
Node.js: Modules must either have a filename ending in .mjs, or the nearest parent package.json file must contain "type": "module". See Node's ECMAScript Modules documentation for more details.
javascript.statements.import 📋Safari3/27/2017 Chrome9/5/2017162
Node.js: Modules must either have a filename ending in .mjs, or the nearest parent package.json file must contain "type": "module". See Node's ECMAScript Modules documentation for more details.Node.js: Modules must either have a filename ending in .mjs, or the nearest parent package.json file must contain "type": "module". See Node's ECMAScript Modules documentation for more details.

2017/4

API First Browser Date Last Browser Date Days Notes
javascript.builtins.String.toLocaleLowerCase.locales_parameter Safari9/20/2016 Chrome4/19/2017211
Deno: Only the locale data for en-US is available.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the function silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.String.toLocaleUpperCase.locales_parameter Safari9/20/2016 Chrome4/19/2017211
Deno: Only the locale data for en-US is available.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the function silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.functions.arrow_functions.trailing_comma Safari9/20/2016 Chrome4/19/2017211
javascript.grammar.trailing_commas.trailing_commas_in_functions Safari9/20/2016 Chrome4/19/2017211
javascript.operators.function.trailing_comma Safari9/20/2016 Chrome4/19/2017211
javascript.operators.generator_function.trailing_comma Safari9/20/2016 Chrome4/19/2017211
javascript.statements.function.trailing_comma_in_parameters Safari9/20/2016 Chrome4/19/2017211
javascript.statements.generator_function.trailing_comma_in_parameters Safari9/20/2016 Chrome4/19/2017211

2017/3

API First Browser Date Last Browser Date Days Notes
javascript.builtins.AsyncFunction 📋Chrome12/1/2016 Safari3/27/2017116
javascript.builtins.AsyncFunction.AsyncFunction 📋Chrome12/1/2016 Safari3/27/2017116
javascript.builtins.Date.UTC.optional_monthIndex Chrome10/25/2011 Safari3/27/20171980
javascript.builtins.Intl.getCanonicalLocales 📋Chrome10/12/2016 Safari3/27/2017166
javascript.builtins.Object.entries 📋Chrome10/12/2016 Safari3/27/2017166
javascript.builtins.Object.values 📋Chrome10/12/2016 Safari3/27/2017166
javascript.functions.method_definitions.async_methods Chrome12/1/2016 Safari3/27/2017116
javascript.operators.async_function 📋Chrome12/1/2016 Safari3/27/2017116
javascript.operators.await 📋Chrome12/1/2016 Safari3/27/2017116
javascript.operators.exponentiation 📋Chrome7/20/2016 Safari3/27/2017250
javascript.operators.exponentiation_assignment 📋Chrome7/20/2016 Safari3/27/2017250
javascript.statements.async_function 📋Chrome12/1/2016 Safari3/27/2017116
javascript.statements.class 📋Chrome3/2/2016 Safari3/27/2017390
Chrome: Strict mode is required.Chrome Android: Strict mode is required.Opera: Strict mode is required.Opera Android: Strict mode is required.Samsung Internet: Strict mode is required.WebView Android: Strict mode is required.
javascript.builtins.String.padEnd 📋Safari9/20/2016 Chrome3/9/2017170
javascript.builtins.String.padStart 📋Safari9/20/2016 Chrome3/9/2017170

2016/10

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Object.getOwnPropertyDescriptors 📋Safari9/20/2016 Chrome10/12/201622

2016/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.@@iterator 📋Chrome10/7/2014 Safari9/20/2016714
Firefox: A placeholder property named @@iterator is used.Firefox: A placeholder property named iterator is used.Firefox for Android: A placeholder property named @@iterator is used.Firefox for Android: A placeholder property named iterator is used.
javascript.builtins.Array.@@species 📋Chrome5/25/2016 Safari9/20/2016118
javascript.builtins.Array.@@unscopables 📋Chrome10/7/2014 Safari9/20/2016714
javascript.builtins.ArrayBuffer.@@species 📋Chrome5/25/2016 Safari9/20/2016118
javascript.builtins.Date.@@toPrimitive 📋Chrome12/1/2015 Safari9/20/2016294
javascript.builtins.Date.toLocaleDateString.locales_parameter Chrome1/10/2013 Safari9/20/20161349
Deno: Only the locale data for en-US is available.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the function silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Date.toLocaleDateString.options_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Date.toLocaleString.locales_parameter Chrome1/10/2013 Safari9/20/20161349
Deno: Only the locale data for en-US is available.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the function silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Date.toLocaleString.options_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Date.toLocaleTimeString.locales_parameter Chrome1/10/2013 Safari9/20/20161349
Deno: Only the locale data for en-US is available.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the function silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Date.toLocaleTimeString.options_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Float32Array.Float32Array.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Float64Array.Float64Array.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Function.@@hasInstance 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.Function.length.configurable_true Chrome5/19/2015 Safari9/20/2016490
javascript.builtins.Function.name.configurable_true Chrome5/19/2015 Safari9/20/2016490
javascript.builtins.Function.name.inferred_names Chrome5/25/2016 Safari9/20/2016118
Edge: Names for functions defined in a dictionary are properly assigned; however, anonymous functions defined on a var/let variable assignment have blank names.
javascript.builtins.Generator 📋Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Generator.next 📋Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Generator.return 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.Generator.throw 📋Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.GeneratorFunction 📋Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.GeneratorFunction.GeneratorFunction 📋Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Int16Array.Int16Array.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Int32Array.Int32Array.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Int8Array.Int8Array.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Intl 📋Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.Collator 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the Collator() constructor for more details.
javascript.builtins.Intl.Collator.Collator 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the Collator instance silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.Collator.Collator.options_ignorePunctuation_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.Collator.Collator.options_localeMatcher_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.Collator.Collator.options_numeric_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.Collator.Collator.options_sensitivity_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.Collator.Collator.options_usage_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.Collator.compare 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the Collator() constructor for more details.
javascript.builtins.Intl.Collator.resolvedOptions 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the Collator() constructor for more details.
javascript.builtins.Intl.Collator.supportedLocalesOf 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.DateTimeFormat 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the DateTimeFormat() constructor for more details.
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the DateTimeFormat instance silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.locales_parameter Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the DateTimeFormat instance silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_timeZoneName_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_timeZone_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.DateTimeFormat.DateTimeFormat.options_parameter.options_timeZone_parameter.iana_time_zones Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.DateTimeFormat.format 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the DateTimeFormat() constructor for more details.
javascript.builtins.Intl.DateTimeFormat.resolvedOptions 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the DateTimeFormat() constructor for more details.
javascript.builtins.Intl.DateTimeFormat.resolvedOptions.computed_timezone Chrome5/20/2014 Safari9/20/2016854
javascript.builtins.Intl.DateTimeFormat.supportedLocalesOf 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.NumberFormat 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the NumberFormat() constructor for more details.
javascript.builtins.Intl.NumberFormat.NumberFormat 📋Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.locales_parameter Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the NumberFormat instance silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_currency_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_localeMatcher_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_maximumFractionDigits_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_maximumSignificantDigits_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_minimumFractionDigits_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_minimumIntegerDigits_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_minimumSignificantDigits_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_style_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Intl.NumberFormat.NumberFormat.options_parameter.options_useGrouping_parameter Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the NumberFormat instance silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Intl.NumberFormat.format 📋Chrome1/10/2013 Safari9/20/20161349
Edge: Before Edge 18, numbers are rounded to 15 decimal digits. For example, new Intl.NumberFormat('en-US').format(1000000000000005) returns "1,000,000,000,000,010".Internet Explorer: In Internet Explorer 11, numbers are rounded to 15 decimal digits. For example, new Intl.NumberFormat('en-US').format(1000000000000005) returns "1,000,000,000,000,010".Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the NumberFormat() constructor for more details.
javascript.builtins.Intl.NumberFormat.resolvedOptions 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. See the NumberFormat() constructor for more details.
javascript.builtins.Intl.NumberFormat.supportedLocalesOf 📋Chrome1/10/2013 Safari9/20/20161349
Node.js: Before version 13.0.0, only the locale data for en-US is available by default. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Iterator 📋Chrome10/7/2014 Safari9/20/2016714
javascript.builtins.Iterator.@@iterator 📋Chrome10/7/2014 Safari9/20/2016714
Firefox: A placeholder property named @@iterator is used.Firefox: A placeholder property named iterator is used.Firefox for Android: A placeholder property named @@iterator is used.Firefox for Android: A placeholder property named iterator is used.
javascript.builtins.Map.@@iterator 📋Chrome10/7/2014 Safari9/20/2016714
Firefox: A placeholder property named @@iterator is used.Firefox: A placeholder property named iterator is used.Firefox for Android: A placeholder property named @@iterator is used.Firefox for Android: A placeholder property named iterator is used.
javascript.builtins.Map.@@species 📋Chrome5/25/2016 Safari9/20/2016118
javascript.builtins.Number.toLocaleString.locales_parameter Chrome1/10/2013 Safari9/20/20161349
Deno: Only the locale data for en-US is available.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the function silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Number.toLocaleString.options_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.Promise.@@species 📋Chrome5/25/2016 Safari9/20/2016118
javascript.builtins.Proxy 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.Proxy 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.apply 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.construct 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.defineProperty 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.deleteProperty 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.get 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.getOwnPropertyDescriptor 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.getPrototypeOf 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.has 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.isExtensible 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.ownKeys 📋Chrome3/2/2016 Safari9/20/2016202
Firefox: In Firefox 42, the implementation got updated to reflect the final ES2015 specification: The result is now checked if it is an array and if the array elements are either of type string or of type symbol. Enumerating duplicate own property names is not a failure anymore.Firefox for Android: In Firefox for Android 42, the implementation got updated to reflect the final ES2015 specification: The result is now checked if it is an array and if the array elements are either of type string or of type symbol. Enumerating duplicate own property names is not a failure anymore.
javascript.builtins.Proxy.handler.preventExtensions 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.set 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Proxy.handler.setPrototypeOf 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.apply 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.construct 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.defineProperty 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.deleteProperty 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.get 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.getOwnPropertyDescriptor 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.getPrototypeOf 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.has 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.isExtensible 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.ownKeys 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.preventExtensions 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.set 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.Reflect.setPrototypeOf 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.RegExp.@@match 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.RegExp.@@replace 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.RegExp.@@search 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.RegExp.@@species 📋Chrome5/25/2016 Safari9/20/2016118
javascript.builtins.RegExp.@@split 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.RegExp.sticky 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.RegExp.sticky.anchored_sticky_flag Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.RegExp.sticky.prototype_accessor Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.RegExp.unicode 📋Chrome4/13/2016 Safari9/20/2016160
Edge: Case folding is implemented in version 13Node.js: Case folding is implemented in version 8.6.0
javascript.builtins.Set.@@species 📋Chrome5/25/2016 Safari9/20/2016118
javascript.builtins.String.localeCompare.locales_parameter Chrome1/10/2013 Safari9/20/20161349
Deno: Only the locale data for en-US is available.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the function silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.String.localeCompare.options_parameter Chrome1/10/2013 Safari9/20/20161349
javascript.builtins.String.normalize 📋Chrome4/8/2014 Safari9/20/2016896
javascript.builtins.Symbol.@@toPrimitive 📋Chrome12/1/2015 Safari9/20/2016294
javascript.builtins.Symbol.hasInstance 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.Symbol.isConcatSpreadable 📋Chrome1/20/2016 Safari9/20/2016244
javascript.builtins.Symbol.iterator 📋Chrome5/19/2015 Safari9/20/2016490
javascript.builtins.Symbol.match 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.Symbol.replace 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.Symbol.search 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.Symbol.species 📋Chrome5/25/2016 Safari9/20/2016118
javascript.builtins.Symbol.split 📋Chrome4/13/2016 Safari9/20/2016160
javascript.builtins.Symbol.toPrimitive 📋Chrome12/1/2015 Safari9/20/2016294
javascript.builtins.Symbol.toStringTag 📋Chrome3/2/2016 Safari9/20/2016202
javascript.builtins.TypedArray.@@iterator 📋Chrome10/7/2014 Safari9/20/2016714
Firefox: A placeholder property named @@iterator is used.Firefox: A placeholder property named iterator is used.Firefox for Android: A placeholder property named @@iterator is used.Firefox for Android: A placeholder property named iterator is used.
javascript.builtins.TypedArray.@@species 📋Chrome5/25/2016 Safari9/20/2016118
javascript.builtins.TypedArray.copyWithin 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.entries 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.every 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.fill 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.filter 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.find 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.findIndex 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.forEach 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.from 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.includes 📋Chrome12/1/2015 Safari9/20/2016294
javascript.builtins.TypedArray.indexOf 📋Chrome9/1/2015 Safari9/20/2016385
Firefox: Starting with Firefox 47, this method will no longer return -0. For example, new Uint8Array([0]).indexOf(0, -0) will now always return +0.Firefox for Android: Starting with Firefox for Android 47, this method will no longer return -0. For example, new Uint8Array([0]).indexOf(0, -0) will now always return +0.
javascript.builtins.TypedArray.iterable_in_constructor Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.TypedArray.join 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.keys 📋Chrome10/7/2014 Safari9/20/2016714
javascript.builtins.TypedArray.lastIndexOf 📋Chrome9/1/2015 Safari9/20/2016385
Firefox: Starting with Firefox 47, this method will no longer return -0. For example, new Uint8Array([0]).lastIndexOf(0, -0) will now always return +0.Firefox for Android: Starting with Firefox for Android 47, this method will no longer return -0. For example, new Uint8Array([0]).lastIndexOf(0, -0) will now always return +0.
javascript.builtins.TypedArray.map 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.of 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.reduce 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.reduceRight 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.reverse 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.slice 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.some 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.sort 📋Chrome9/1/2015 Safari9/20/2016385
javascript.builtins.TypedArray.values 📋Chrome10/7/2014 Safari9/20/2016714
javascript.builtins.Uint16Array.Uint16Array.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Uint32Array.Uint32Array.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Uint8Array.Uint8Array.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.builtins.Uint8ClampedArray.Uint8ClampedArray.iterable_allowed Chrome11/18/2014 Safari9/20/2016672
javascript.functions.arrow_functions 📋Chrome9/1/2015 Safari9/20/2016385
Firefox: The initial implementation of arrow functions in Firefox made them automatically strict. This has been changed as of Firefox 24. The use of 'use strict'; is now required.Firefox: Before Firefox 39, a line terminator (\n) was incorrectly allowed after arrow function arguments. This has been fixed to conform to the ES2015 specification and code like () \n => {} will now throw a SyntaxError in this and later versions.Firefox for Android: The initial implementation of arrow functions in Firefox for Android made them automatically strict. This has been changed as of Firefox for Android 24. The use of 'use strict'; is now required.Firefox for Android: Before Firefox for Android 39, a line terminator (\n) was incorrectly allowed after arrow function arguments. This has been fixed to conform to the ES2015 specification and code like () \n => {} will now throw a SyntaxError in this and later versions.
javascript.functions.block_level_functions Chrome3/2/2016 Safari9/20/2016202
javascript.functions.default_parameters 📋Chrome3/2/2016 Safari9/20/2016202
javascript.functions.default_parameters.destructured_parameter_with_default_value_assignment Chrome3/2/2016 Safari9/20/2016202
javascript.functions.default_parameters.parameters_without_defaults_after_default_parameters Chrome3/2/2016 Safari9/20/2016202
javascript.functions.rest_parameters 📋Chrome12/1/2015 Safari9/20/2016294
javascript.functions.rest_parameters.destructuring Chrome3/2/2016 Safari9/20/2016202
javascript.operators.destructuring.computed_property_names Chrome3/2/2016 Safari9/20/2016202
javascript.operators.generator_function 📋Chrome3/2/2016 Safari9/20/2016202
javascript.operators.yield 📋Chrome11/18/2014 Safari9/20/2016672
Firefox: Starting with Firefox 33, the parsing of the yield expression has been updated to conform with the ES2015 specification.Firefox: Starting with Firefox 29, an IteratorResult object returned for completed generator function.Firefox for Android: Starting with Firefox for Android 33, the parsing of the yield expression has been updated to conform with the ES2015 specification.Firefox for Android: Starting with Firefox for Android 29, an IteratorResult object returned for completed generator function.
javascript.operators.yield_star 📋Chrome11/18/2014 Safari9/20/2016672
Firefox: Starting with Firefox 33, the parsing of the yield expression has been updated to conform with the ES2015 specification.Firefox for Android: Starting with Firefox for Android 33, the parsing of the yield expression has been updated to conform with the ES2015 specification.
javascript.regular_expressions.character_escape.unicode Chrome4/13/2016 Safari9/20/2016160
javascript.statements.generator_function 📋Chrome11/18/2014 Safari9/20/2016672
javascript.statements.generator_function.IteratorResult_object Chrome3/2/2016 Safari9/20/2016202
javascript.statements.generator_function.not_constructable_with_new Chrome4/13/2016 Safari9/20/2016160
javascript.statements.let 📋Chrome3/2/2016 Safari9/20/2016202
Chrome: Strict mode is required.Chrome Android: Strict mode is required.Edge: In Edge 12 and 13, let within a for loop initializer does not create a separate variable for each loop iteration as defined by ES2015. Instead, it behaves as though the loop were wrapped in a scoping block with the let immediately before the loop.Firefox: Before Firefox 44, let is only available to code blocks in HTML wrapped in a <script type="application/javascript;version=1.7"> block (or higher version) and has different semantics (e.g. no temporal dead zone).Firefox: Before Firefox 46, a TypeError is thrown on redeclaration instead of a SyntaxError.Firefox: Firefox 54 adds support of let in workers.Firefox for Android: Before Firefox for Android 44, let is only available to code blocks in HTML wrapped in a <script type="application/javascript;version=1.7"> block (or higher version) and has different semantics (e.g. no temporal dead zone).Firefox for Android: Before Firefox for Android 46, a TypeError is thrown on redeclaration instead of a SyntaxError.Firefox for Android: Firefox for Android 54 adds support of let in workers.Internet Explorer: In Internet Explorer, let within a for loop initializer does not create a separate variable for each loop iteration as defined by ES2015. Instead, it behaves as though the loop were wrapped in a scoping block with the let immediately before the loop.Samsung Internet: Strict mode is required.WebView Android: Strict mode is required.

2016/7

API First Browser Date Last Browser Date Days Notes
javascript.functions.arguments.@@iterator 📋Safari9/30/2015 Chrome7/20/2016294

2016/5

API First Browser Date Last Browser Date Days Notes
javascript.statements.for_of.closing_iterators Safari10/22/2013 Chrome5/25/2016946

2016/3

API First Browser Date Last Browser Date Days Notes
javascript.functions.get.computed_property_names Chrome10/13/2015 Safari3/21/2016160
javascript.functions.method_definitions.generator_methods_not_constructable Chrome4/14/2015 Safari3/21/2016342
javascript.functions.set.computed_property_names Chrome10/13/2015 Safari3/21/2016160
javascript.operators.destructuring.rest_in_arrays Chrome3/2/2016 Safari3/21/201619
javascript.builtins.RegExp.flags 📋Safari9/30/2015 Chrome3/2/2016154
javascript.classes 📋Safari9/30/2015 Chrome3/2/2016154
Chrome: Strict mode is required.Chrome Android: Strict mode is required.Opera: Strict mode is required.Opera Android: Strict mode is required.Samsung Internet: Strict mode is required.WebView Android: Strict mode is required.
javascript.classes.constructor 📋Safari9/30/2015 Chrome3/2/2016154
Chrome: Strict mode is required.Chrome Android: Strict mode is required.Opera: Strict mode is required.Opera Android: Strict mode is required.Samsung Internet: Strict mode is required.WebView Android: Strict mode is required.
javascript.classes.extends 📋Safari9/30/2015 Chrome3/2/2016154
Chrome: Strict mode is required.Chrome Android: Strict mode is required.Opera: Strict mode is required.Opera Android: Strict mode is required.Samsung Internet: Strict mode is required.WebView Android: Strict mode is required.
javascript.classes.static 📋Safari9/30/2015 Chrome3/2/2016154
Chrome: Strict mode is required.Chrome Android: Strict mode is required.Opera: Strict mode is required.Opera Android: Strict mode is required.Samsung Internet: Strict mode is required.WebView Android: Strict mode is required.
javascript.operators.destructuring 📋Safari10/16/2014 Chrome3/2/2016503
Firefox: Firefox provided a non-standard destructuring implementation from Firefox 2 to 40.Firefox for Android: Firefox for Android provided a non-standard destructuring implementation from Firefox for Android 4 to 40.

2016/1

API First Browser Date Last Browser Date Days Notes
javascript.builtins.RegExp.global.prototype_accessor Safari4/15/2005 Chrome1/20/20163932
javascript.builtins.RegExp.ignoreCase.prototype_accessor Safari4/15/2005 Chrome1/20/20163932
javascript.builtins.RegExp.multiline.prototype_accessor Safari4/15/2005 Chrome1/20/20163932
javascript.builtins.RegExp.source.prototype_accessor Safari4/15/2005 Chrome1/20/20163932

2015/12

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.includes 📋Safari9/30/2015 Chrome12/1/201562
javascript.operators.object_initializer.computed_property_names Safari10/16/2014 Chrome12/1/2015411
javascript.operators.object_initializer.shorthand_method_names Safari9/30/2015 Chrome12/1/201562
javascript.operators.object_initializer.shorthand_property_names Safari9/30/2015 Chrome12/1/201562

2015/10

API First Browser Date Last Browser Date Days Notes
javascript.operators.spread 📋Safari10/16/2014 Chrome10/13/2015362
javascript.operators.spread.spread_in_arrays 📋Safari10/16/2014 Chrome10/13/2015362
javascript.operators.spread.spread_in_function_calls 📋Safari10/16/2014 Chrome10/13/2015362

2015/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.copyWithin 📋Chrome9/1/2015 Safari9/30/201529
javascript.builtins.Array.from 📋Chrome9/1/2015 Safari9/30/201529
javascript.builtins.Array.of 📋Chrome9/1/2015 Safari9/30/201529
javascript.builtins.Map.Map.iterable_allowed Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Map.Map.null_allowed Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Map.key_equality_for_zeros Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Math.sign 📋Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Number.EPSILON 📋Chrome4/8/2014 Safari9/30/2015540
javascript.builtins.Number.MAX_SAFE_INTEGER 📋Chrome4/8/2014 Safari9/30/2015540
javascript.builtins.Number.MIN_SAFE_INTEGER 📋Chrome4/8/2014 Safari9/30/2015540
javascript.builtins.Number.isFinite 📋Chrome5/15/2012 Safari9/30/20151233
javascript.builtins.Number.isInteger 📋Chrome4/8/2014 Safari9/30/2015540
javascript.builtins.Number.isNaN 📋Chrome2/21/2013 Safari9/30/2015951
javascript.builtins.Number.isSafeInteger 📋Chrome4/8/2014 Safari9/30/2015540
javascript.builtins.Number.parseFloat 📋Chrome4/8/2014 Safari9/30/2015540
javascript.builtins.Number.parseInt 📋Chrome4/8/2014 Safari9/30/2015540
javascript.builtins.Object.assign 📋Chrome9/1/2015 Safari9/30/201529
javascript.builtins.Object.getOwnPropertySymbols 📋Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Object.is 📋Chrome5/15/2012 Safari9/30/20151233
javascript.builtins.Object.preventExtensions.ES2015_behavior Chrome7/21/2015 Safari9/30/201571
javascript.builtins.Object.setPrototypeOf 📋Chrome4/8/2014 Safari9/30/2015540
javascript.builtins.Set.@@iterator 📋Chrome5/19/2015 Safari9/30/2015134
Firefox: A placeholder property named @@iterator is used.Firefox: A placeholder property named iterator is used.Firefox for Android: A placeholder property named @@iterator is used.Firefox for Android: A placeholder property named iterator is used.
javascript.builtins.Set.Set.iterable_allowed Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Set.Set.null_allowed Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Set.key_equality_for_zeros Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.String.@@iterator 📋Chrome10/7/2014 Safari9/30/2015358
Firefox: A placeholder property named @@iterator is used.Firefox: A placeholder property named iterator is used.Firefox for Android: A placeholder property named @@iterator is used.Firefox for Android: A placeholder property named iterator is used.
javascript.builtins.String.codePointAt 📋Chrome3/3/2015 Safari9/30/2015211
javascript.builtins.String.endsWith 📋Chrome3/3/2015 Safari9/30/2015211
javascript.builtins.String.fromCodePoint 📋Chrome3/3/2015 Safari9/30/2015211
javascript.builtins.String.includes 📋Chrome3/3/2015 Safari9/30/2015211
javascript.builtins.String.raw 📋Chrome3/3/2015 Safari9/30/2015211
javascript.builtins.String.repeat 📋Chrome3/3/2015 Safari9/30/2015211
javascript.builtins.String.startsWith 📋Chrome3/3/2015 Safari9/30/2015211
javascript.builtins.Symbol 📋Chrome10/7/2014 Safari9/30/2015358
Edge: Edge 12 included Symbol properties in JSON.stringify() output.
javascript.builtins.Symbol.Symbol 📋Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Symbol.for 📋Chrome1/21/2015 Safari9/30/2015252
javascript.builtins.Symbol.keyFor 📋Chrome1/21/2015 Safari9/30/2015252
javascript.builtins.Symbol.toString 📋Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Symbol.unscopables 📋Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.Symbol.valueOf 📋Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.WeakMap.WeakMap.iterable_allowed Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.WeakSet 📋Chrome7/16/2014 Safari9/30/2015441
javascript.builtins.WeakSet.WeakSet 📋Chrome7/16/2014 Safari9/30/2015441
javascript.builtins.WeakSet.WeakSet.iterable_allowed Chrome10/7/2014 Safari9/30/2015358
javascript.builtins.WeakSet.WeakSet.null_allowed Chrome7/16/2014 Safari9/30/2015441
javascript.builtins.WeakSet.add 📋Chrome7/16/2014 Safari9/30/2015441
javascript.builtins.WeakSet.delete 📋Chrome7/16/2014 Safari9/30/2015441
javascript.builtins.WeakSet.has 📋Chrome7/16/2014 Safari9/30/2015441
javascript.functions.method_definitions 📋Chrome11/18/2014 Safari9/30/2015316
javascript.grammar.binary_numeric_literals 📋Chrome3/3/2015 Safari9/30/2015211
javascript.grammar.octal_numeric_literals 📋Chrome3/3/2015 Safari9/30/2015211
javascript.grammar.shorthand_object_literals Chrome5/19/2015 Safari9/30/2015134
javascript.grammar.template_literals 📋Chrome3/3/2015 Safari9/30/2015211
javascript.grammar.unicode_point_escapes 📋Chrome7/21/2015 Safari9/30/201571
javascript.builtins.Array.fill 📋Safari10/16/2014 Chrome9/1/2015320
javascript.builtins.Array.find 📋Safari10/16/2014 Chrome9/1/2015320
javascript.builtins.Array.findIndex 📋Safari10/16/2014 Chrome9/1/2015320

2015/4

API First Browser Date Last Browser Date Days Notes
javascript.operators.class 📋Safari10/22/2013 Chrome4/14/2015539
javascript.operators.super 📋Safari10/22/2013 Chrome4/14/2015539

2014/10

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.entries 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Array.keys 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.Map 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.clear 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.delete 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.entries 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.forEach 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.get 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.has 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.keys 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Map.set 📋Chrome10/7/2014 Safari10/16/20149
Internet Explorer: Returns 'undefined' instead of the 'Map' object.
javascript.builtins.Map.size 📋Chrome10/7/2014 Safari10/16/20149
Firefox: From Firefox 13 to Firefox 18, the size property was implemented as a Map.prototype.size() method, this has been changed to a property in later versions conform to the ECMAScript 2015 specification.Firefox for Android: From Firefox for Android 14 to Firefox for Android 18, the size property was implemented as a Map.prototype.size() method, this has been changed to a property in later versions conform to the ECMAScript 2015 specification.
javascript.builtins.Map.values 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.acosh 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.asinh 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.atanh 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.cbrt 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.cosh 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.expm1 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.fround 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.hypot 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.log10 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.log1p 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.log2 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.sinh 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.tanh 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Math.trunc 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Promise 📋Chrome1/14/2014 Safari10/16/2014275
javascript.builtins.Promise.Promise 📋Chrome1/14/2014 Safari10/16/2014275
Firefox: Constructor requires a new operator since version 37.Firefox for Android: Constructor requires a new operator since version 37.Node.js: Constructor requires a new operator since version 4.Safari: Constructor requires a new operator since version 10.Safari on iOS: Constructor requires a new operator since version 10.WebView on iOS: Constructor requires a new operator since version 10.
javascript.builtins.Promise.all 📋Chrome1/14/2014 Safari10/16/2014275
javascript.builtins.Promise.catch 📋Chrome1/14/2014 Safari10/16/2014275
javascript.builtins.Promise.race 📋Chrome1/14/2014 Safari10/16/2014275
javascript.builtins.Promise.reject 📋Chrome1/14/2014 Safari10/16/2014275
javascript.builtins.Promise.resolve 📋Chrome1/14/2014 Safari10/16/2014275
javascript.builtins.Promise.then 📋Chrome1/14/2014 Safari10/16/2014275
javascript.builtins.Set 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Set.Set 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Set.add 📋Chrome10/7/2014 Safari10/16/20149
Internet Explorer: Returns 'undefined' instead of the 'Set' object.
javascript.builtins.Set.clear 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Set.delete 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Set.entries 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Set.forEach 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Set.has 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Set.keys 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.Set.size 📋Chrome10/7/2014 Safari10/16/20149
Firefox: From Firefox 13 to Firefox 18, the size property was implemented as a Set.prototype.size() method, this has been changed to a property in later versions conform to the ECMAScript 2015 specification.Firefox for Android: From Firefox for Android 14 to Firefox for Android 18, the size property was implemented as a Set.prototype.size() method, this has been changed to a property in later versions conform to the ECMAScript 2015 specification.
javascript.builtins.Set.values 📋Chrome10/7/2014 Safari10/16/20149
javascript.builtins.WeakMap 📋Chrome7/16/2014 Safari10/16/201492
javascript.builtins.WeakMap.WeakMap 📋Chrome7/16/2014 Safari10/16/201492
javascript.builtins.WeakMap.WeakMap.null_allowed Chrome7/16/2014 Safari10/16/201492
javascript.builtins.WeakMap.delete 📋Chrome7/16/2014 Safari10/16/201492
Firefox: Before Firefox 38, this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard.Firefox for Android: Before Firefox for Android 38, this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard.
javascript.builtins.WeakMap.get 📋Chrome7/16/2014 Safari10/16/201492
Firefox: Before Firefox 38, this method threw a TypeError when the key parameter was not an object. However, the ES2015 specification specifies to return undefined instead. Furthermore, WeakMap.prototype.get accepted an optional second argument as a fallback value, which is not part of the standard. Both non-standard behaviors are removed in version 38 and higher.Firefox for Android: Before Firefox for Android 38, this method threw a TypeError when the key parameter was not an object. However, the ES2015 specification specifies to return undefined instead. Furthermore, WeakMap.prototype.get accepted an optional second argument as a fallback value, which is not part of the standard. Both non-standard behaviors are removed in version 38 and higher.
javascript.builtins.WeakMap.has 📋Chrome7/16/2014 Safari10/16/201492
Firefox: Before Firefox 38, this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard.Firefox for Android: Before Firefox for Android 38, this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard.
javascript.builtins.WeakMap.set 📋Chrome7/16/2014 Safari10/16/201492
Firefox: Before Firefox 38, this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard.Firefox for Android: Before Firefox for Android 38, this method threw a TypeError when the key parameter was not an object. This has been fixed in version 38 and later to return false as per the ES2015 standard.Internet Explorer: Returns 'undefined' instead of the 'Map' object.
javascript.builtins.Math.clz32 📋Safari10/22/2013 Chrome10/7/2014350
javascript.statements.for_of 📋Safari10/22/2013 Chrome10/7/2014350
Firefox: Before Firefox 51, using the for...of loop construct with the const keyword threw a SyntaxError ("missing = in const declaration").Firefox for Android: Before Firefox for Android 51, using the for...of loop construct with the const keyword threw a SyntaxError ("missing = in const declaration").

2014/1

API First Browser Date Last Browser Date Days Notes
javascript.builtins.ArrayBuffer.isView 📋Safari10/22/2013 Chrome1/14/201484

2013/10

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.toLocaleString.locales_parameter Chrome1/10/2013 Safari10/22/2013285
Deno: Only the locale data for en-US is available.Node.js: Before version 13.0.0, only the locale data for en-US is available by default. When other locales are specified, the function silently falls back to en-US. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.
javascript.builtins.Array.toLocaleString.options_parameter Chrome1/10/2013 Safari10/22/2013285
javascript.builtins.Date.toLocaleDateString.iana_time_zone_names Chrome1/10/2013 Safari10/22/2013285
javascript.builtins.Date.toLocaleString.iana_time_zone_names Chrome1/10/2013 Safari10/22/2013285
javascript.builtins.Date.toLocaleTimeString.iana_time_zone_names Chrome1/10/2013 Safari10/22/2013285
javascript.builtins.Math.imul 📋Chrome7/9/2013 Safari10/22/2013105

2012/11

API First Browser Date Last Browser Date Days Notes
javascript.builtins.parseInt.leading_zero_strings_as_decimal Safari7/25/2012 Chrome11/6/2012104

2012/7

API First Browser Date Last Browser Date Days Notes
javascript.statements.const 📋Safari7/20/2011 Chrome7/31/2012377
Firefox: Before Firefox 13, const is implemented, but re-assignment is not failing.Firefox: Before Firefox 46, a TypeError was thrown on redeclaration instead of a SyntaxError.Firefox for Android: Before Firefox for Android 14, const is implemented, but re-assignment is not failing.Firefox for Android: Before Firefox for Android 46, a TypeError was thrown on redeclaration instead of a SyntaxError.
javascript.builtins.Error.stack Chrome9/15/2009 Safari7/25/20121044
javascript.builtins.Function.apply.generic_arrays_as_arguments Chrome2/8/2012 Safari7/25/2012168
javascript.builtins.Function.name 📋Chrome10/25/2011 Safari7/25/2012274

2012/2

API First Browser Date Last Browser Date Days Notes
javascript.builtins.ArrayBuffer.slice 📋Safari7/20/2011 Chrome2/8/2012203
Firefox: The non-standard ArrayBuffer.slice() method has been removed in Firefox 53 (but the standardized version ArrayBuffer.prototype.slice() is kept.Firefox for Android: The non-standard ArrayBuffer.slice() method has been removed in Firefox for Android 53 (but the standardized version ArrayBuffer.prototype.slice() is kept.

2011/7

API First Browser Date Last Browser Date Days Notes
javascript.builtins.ArrayBuffer 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.ArrayBuffer.ArrayBuffer 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.ArrayBuffer.byteLength 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.DataView 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.DataView 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.buffer 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.byteLength 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.byteOffset 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.getFloat32 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.getFloat64 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.getInt16 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.getInt32 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.getInt8 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.getUint16 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.getUint32 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.getUint8 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.setFloat32 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.setFloat64 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.setInt16 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.setInt32 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.setInt8 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.setUint16 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.setUint32 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.DataView.setUint8 📋Chrome2/3/2011 Safari7/20/2011167
javascript.builtins.Date.parse.iso_8601 Chrome9/2/2010 Safari7/20/2011321
javascript.builtins.Float32Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Float32Array.Float32Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Float32Array.Float32Array.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Float64Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Float64Array.Float64Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Float64Array.Float64Array.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Function.bind 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int16Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int16Array.Int16Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int16Array.Int16Array.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int32Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int32Array.Int32Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int32Array.Int32Array.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int8Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int8Array.Int8Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Int8Array.Int8Array.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Object.defineProperty 📋Chrome5/25/2010 Safari7/20/2011421
Internet Explorer: In Internet Explorer 8, this was only supported on DOM objects and with some non-standard behaviors. This was later fixed in Internet Explorer 9.Safari: Also supported in Safari 5, but not on DOM objects.Safari on iOS: Also supported in Safari for iOS 4.2, but not on DOM objects.WebView on iOS: Also supported in Safari for iOS 4.2, but not on DOM objects.
javascript.builtins.Object.freeze 📋Chrome9/2/2010 Safari7/20/2011321
javascript.builtins.Object.isExtensible 📋Chrome9/2/2010 Safari7/20/2011321
javascript.builtins.Object.isFrozen 📋Chrome9/2/2010 Safari7/20/2011321
javascript.builtins.Object.isSealed 📋Chrome9/2/2010 Safari7/20/2011321
javascript.builtins.Object.preventExtensions 📋Chrome9/2/2010 Safari7/20/2011321
javascript.builtins.Object.seal 📋Chrome9/2/2010 Safari7/20/2011321
javascript.builtins.TypedArray 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.BYTES_PER_ELEMENT 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.buffer 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.byteLength 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.byteOffset 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.index_properties_not_consulting_prototype Chrome10/19/2010 Safari7/20/2011274
Bun: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Chrome: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Chrome Android: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Deno: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Edge: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Internet Explorer: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Node.js: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Quest Browser: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Opera: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Opera Android: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Safari: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Safari on iOS: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.Samsung Internet: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.WebView Android: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.WebView on iOS: Negative integers are not considered as indexed properties and therefore return the value of the prototype property.
javascript.builtins.TypedArray.length 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.name 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.named_properties Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.set 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.subarray 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.toLocaleString 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.TypedArray.toString 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint16Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint16Array.Uint16Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint16Array.Uint16Array.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint32Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint32Array.Uint32Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint32Array.Uint32Array.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint8Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint8Array.Uint8Array 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint8Array.Uint8Array.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint8ClampedArray 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint8ClampedArray.Uint8ClampedArray 📋Chrome10/19/2010 Safari7/20/2011274
javascript.builtins.Uint8ClampedArray.Uint8ClampedArray.constructor_without_parameters Chrome10/19/2010 Safari7/20/2011274

2010/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.RegExp.source.empty_regex_string Safari6/7/2010 Chrome9/2/201087

2010/6

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.isArray 📋Chrome1/25/2010 Safari6/7/2010133
javascript.builtins.Object.create 📋Chrome5/25/2010 Safari6/7/201013
javascript.builtins.Object.defineProperties 📋Chrome5/25/2010 Safari6/7/201013
javascript.builtins.Object.getOwnPropertyDescriptor 📋Chrome5/25/2010 Safari6/7/201013
Internet Explorer: In Internet Explorer 8, this was only supported on DOM objects and with some non-standard behaviors. This was later fixed in Internet Explorer 9.
javascript.builtins.Object.getOwnPropertyNames 📋Chrome5/25/2010 Safari6/7/201013
javascript.builtins.Object.getPrototypeOf 📋Chrome5/25/2010 Safari6/7/201013
javascript.builtins.Object.keys 📋Chrome5/25/2010 Safari6/7/201013
javascript.builtins.String.trim 📋Chrome1/25/2010 Safari6/7/2010133
javascript.statements.debugger 📋Chrome5/25/2010 Safari6/7/201013
javascript.statements.empty 📋Chrome9/15/2009 Safari6/7/2010265

2009/9

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array.reduce 📋Safari6/8/2009 Chrome9/15/200999
javascript.builtins.Array.reduceRight 📋Safari6/8/2009 Chrome9/15/200999
javascript.builtins.Date.toISOString 📋Safari6/8/2009 Chrome9/15/200999
javascript.builtins.Date.toJSON 📋Safari6/8/2009 Chrome9/15/200999
javascript.builtins.JSON 📋Safari6/8/2009 Chrome9/15/200999
javascript.builtins.JSON.parse 📋Safari6/8/2009 Chrome9/15/200999
javascript.builtins.JSON.stringify 📋Safari6/8/2009 Chrome9/15/200999

2009/6

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Date.now 📋Chrome12/11/2008 Safari6/8/2009179
javascript.operators.decrement 📋Chrome5/21/2009 Safari6/8/200918
javascript.operators.increment 📋Chrome5/21/2009 Safari6/8/200918

2008/12

API First Browser Date Last Browser Date Days Notes
javascript.builtins.Array 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.Array 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.concat 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.every 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Array.filter 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Array.forEach 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Array.indexOf 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Array.join 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.lastIndexOf 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Array.length 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.map 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Array.pop 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.push 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.reverse 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.shift 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.slice 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.some 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Array.sort 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.splice 📋Safari6/23/2003 Chrome12/11/20081998
Internet Explorer: From Internet Explorer 5.5 through 8, all elements of the array will not be deleted if deleteCount is omitted. This behavior was fixed in Internet Explorer 9.
javascript.builtins.Array.toLocaleString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Array.unshift 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Boolean 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Boolean.Boolean 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Boolean.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Boolean.valueOf 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date 📋Safari6/23/2003 Chrome12/11/20081998
Internet Explorer: The ISO8601 Date Format is not supported in Internet Explorer 8 or earlier.
javascript.builtins.Date.Date 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.UTC 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getDate 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getDay 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getFullYear 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getHours 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getMilliseconds 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getMinutes 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getMonth 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getSeconds 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getTime 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getTimezoneOffset 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getUTCDate 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getUTCDay 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getUTCFullYear 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getUTCHours 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getUTCMilliseconds 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getUTCMinutes 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getUTCMonth 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getUTCSeconds 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.getYear 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.parse 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setDate 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setFullYear 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setHours 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setMilliseconds 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setMinutes 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setMonth 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setSeconds 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setTime 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setUTCDate 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setUTCFullYear 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setUTCHours 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setUTCMilliseconds 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setUTCMinutes 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setUTCMonth 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setUTCSeconds 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.setYear 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.toDateString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.toGMTString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.toLocaleDateString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.toLocaleString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.toLocaleTimeString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.toTimeString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.toUTCString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Date.valueOf 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Error 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Error.Error 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Error.message 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Error.name 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Error.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.EvalError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.EvalError.EvalError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Function 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Function.Function 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Function.apply 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Function.arguments Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Function.call 📋Safari6/23/2003 Chrome12/11/20081998
Node.js: When calling this method, thisArg does not default to the global object.
javascript.builtins.Function.caller Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Function.length 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Function.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Infinity 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.E 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.LN10 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.LN2 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.LOG10E 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.LOG2E 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.PI 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.SQRT1_2 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.SQRT2 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.abs 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.acos 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.asin 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.atan 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.atan2 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.ceil 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.cos 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.exp 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.floor 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.log 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.max 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.min 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.pow 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.random 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.round 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.sin 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.sqrt 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Math.tan 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.NaN 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number.MAX_VALUE 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number.MIN_VALUE 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number.NEGATIVE_INFINITY 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number.NaN 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number.Number 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number.POSITIVE_INFINITY 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number.toExponential 📋Safari4/29/2005 Chrome12/11/20081322
javascript.builtins.Number.toFixed 📋Safari4/29/2005 Chrome12/11/20081322
javascript.builtins.Number.toLocaleString 📋Safari6/23/2003 Chrome12/11/20081998
Edge: Before Edge 18, numbers are rounded to 15 decimal digits. For example, (1000000000000005).toLocaleString('en-US') returns "1,000,000,000,000,010".Internet Explorer: In Internet Explorer 11, numbers are rounded to 15 decimal digits. For example, (1000000000000005).toLocaleString('en-US') returns "1,000,000,000,000,010".
javascript.builtins.Number.toPrecision 📋Safari4/29/2005 Chrome12/11/20081322
javascript.builtins.Number.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Number.valueOf 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Object 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Object.Object 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Object.constructor 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Object.defineGetter 📋Safari10/26/2007 Chrome12/11/2008412
Firefox: Starting with Firefox 48, this method can no longer be called at the global scope without any object. A TypeError will be thrown otherwise. Previously, the global object was used in these cases automatically, but this is no longer the case.
javascript.builtins.Object.defineSetter 📋Safari10/26/2007 Chrome12/11/2008412
Firefox: Starting with Firefox 48, this method can no longer be called at the global scope without any object. A TypeError will be thrown otherwise. Previously, the global object was used in these cases automatically, but this is no longer the case.
javascript.builtins.Object.hasOwnProperty 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Object.isPrototypeOf 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Object.lookupGetter 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Object.lookupSetter 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Object.propertyIsEnumerable 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Object.proto 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.Object.toLocaleString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Object.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.Object.valueOf 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RangeError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RangeError.RangeError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.ReferenceError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.ReferenceError.ReferenceError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.RegExp 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.compile 📋Safari3/18/2008 Chrome12/11/2008268
javascript.builtins.RegExp.exec 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.global 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.ignoreCase 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.input 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.RegExp.lastIndex 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.lastMatch 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.RegExp.lastParen 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.RegExp.leftContext 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.RegExp.multiline 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.n 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.rightContext 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.RegExp.source 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.test 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.RegExp.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.String 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.anchor 📋Safari6/23/2003 Chrome12/11/20081998
Firefox: Starting with version 17, the quotation mark (") is replaced by its HTML reference character (") in strings supplied for the name parameter.
javascript.builtins.String.big 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.blink 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.bold 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.charAt 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.charCodeAt 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.concat 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.fixed 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.fontcolor 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.fontsize 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.fromCharCode 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.indexOf 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.italics 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.lastIndexOf 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.length 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.link 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.localeCompare 📋Safari10/26/2007 Chrome12/11/2008412
javascript.builtins.String.match 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.replace 📋Safari6/23/2003 Chrome12/11/20081998
Internet Explorer: A replacement function as second argument is not supported.
javascript.builtins.String.search 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.slice 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.small 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.split 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.strike 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.sub 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.substr 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.substring 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.sup 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.toLocaleLowerCase 📋Safari4/15/2005 Chrome12/11/20081336
javascript.builtins.String.toLocaleUpperCase 📋Safari4/15/2005 Chrome12/11/20081336
javascript.builtins.String.toLowerCase 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.toString 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.toUpperCase 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.unicode_code_point_escapes Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.String.valueOf 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.SyntaxError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.SyntaxError.SyntaxError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.TypeError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.TypeError.TypeError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.URIError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.URIError.URIError 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.decodeURI 📋Safari10/24/2003 Chrome12/11/20081875
javascript.builtins.decodeURIComponent 📋Safari10/24/2003 Chrome12/11/20081875
javascript.builtins.encodeURI 📋Safari10/24/2003 Chrome12/11/20081875
javascript.builtins.encodeURIComponent 📋Safari10/24/2003 Chrome12/11/20081875
javascript.builtins.escape 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.eval 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.isFinite 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.isNaN 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.parseFloat 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.parseInt 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.undefined 📋Safari6/23/2003 Chrome12/11/20081998
javascript.builtins.unescape 📋Safari6/23/2003 Chrome12/11/20081998
javascript.functions 📋Safari6/23/2003 Chrome12/11/20081998
javascript.functions.arguments 📋Safari6/23/2003 Chrome12/11/20081998
javascript.functions.arguments.callee 📋Safari6/23/2003 Chrome12/11/20081998
javascript.functions.arguments.length 📋Safari6/23/2003 Chrome12/11/20081998
javascript.functions.get 📋Safari10/26/2007 Chrome12/11/2008412
javascript.functions.set 📋Safari10/26/2007 Chrome12/11/2008412
javascript.grammar.array_literals 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.boolean_literals 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.decimal_numeric_literals 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.hexadecimal_escape_sequences 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.hexadecimal_numeric_literals 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.null_literal 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.regular_expression_literals 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.string_literals 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.trailing_commas 📋Safari6/23/2003 Chrome12/11/20081998
javascript.grammar.trailing_commas.trailing_commas_in_object_literals Safari10/26/2007 Chrome12/11/2008412
javascript.grammar.unicode_escape_sequences 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.addition 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.addition_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.bitwise_and 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.bitwise_and_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.bitwise_not 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.bitwise_or 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.bitwise_or_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.bitwise_xor 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.bitwise_xor_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.comma 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.conditional 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.delete 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.division 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.division_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.equality 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.function 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.greater_than 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.greater_than_or_equal 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.grouping 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.in 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.inequality 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.instanceof 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.left_shift 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.left_shift_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.less_than 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.less_than_or_equal 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.logical_and 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.logical_not 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.logical_or 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.multiplication 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.multiplication_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.new 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.null 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.object_initializer 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.property_accessors 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.remainder 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.remainder_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.right_shift 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.right_shift_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.strict_equality 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.strict_inequality 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.subtraction 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.subtraction_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.this 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.typeof 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.unary_negation 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.unary_plus 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.unsigned_right_shift 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.unsigned_right_shift_assignment 📋Safari6/23/2003 Chrome12/11/20081998
javascript.operators.void 📋Safari3/18/2008 Chrome12/11/2008268
javascript.regular_expressions.backreference 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.capturing_group 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.character_class 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.character_class_escape 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.character_escape 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.disjunction 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.input_boundary_assertion 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.literal_character 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.lookahead_assertion 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.non_capturing_group 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.quantifier 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.wildcard 📋Safari6/23/2003 Chrome12/11/20081998
javascript.regular_expressions.word_boundary_assertion 📋Safari6/23/2003 Chrome12/11/20081998
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javascript.statements.break 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.continue 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.do_while 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.for 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.for_in 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.function 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.if_else 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.label 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.return 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.switch 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.throw 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.try_catch 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.var 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.while 📋Safari6/23/2003 Chrome12/11/20081998
javascript.statements.with 📋Safari6/23/2003 Chrome12/11/20081998