Not yet stable

For a given set of browsers, what APIs are not yet in all of them.

Example Comparisons
Browsers
Features

Summary

A count of the number of APIs are in Browser X but not in Browser Y.
Not in FirefoxNot in Safari
In Firefox 296
In Safari 14

Unstable APIs

Below is a list of features that are not in all of Firefox and Safari

Raw Data

Quick Links:

JS Data

API First Browser Date Days in Limbo Notes
javascript.builtins.AsyncDisposableStack 📋Firefox7/22/2025240
javascript.builtins.AsyncDisposableStack.@@asyncDispose 📋Firefox7/22/2025240
javascript.builtins.AsyncDisposableStack.AsyncDisposableStack 📋Firefox7/22/2025240
javascript.builtins.AsyncDisposableStack.adopt 📋Firefox7/22/2025240
javascript.builtins.AsyncDisposableStack.defer 📋Firefox7/22/2025240
javascript.builtins.AsyncDisposableStack.disposeAsync 📋Firefox7/22/2025240
javascript.builtins.AsyncDisposableStack.disposed 📋Firefox7/22/2025240
javascript.builtins.AsyncDisposableStack.move 📋Firefox7/22/2025240
javascript.builtins.AsyncDisposableStack.use 📋Firefox7/22/2025240
javascript.builtins.AsyncFunction.AsyncFunction.enforces_trusted_types 📋Safari9/15/2025185
javascript.builtins.AsyncGeneratorFunction.AsyncGeneratorFunction.enforces_trusted_types 📋Safari9/15/2025185
javascript.builtins.AsyncIterator.@@asyncDispose 📋Firefox7/22/2025240
javascript.builtins.Atomics.Atomic_operations_on_non_shared_buffers Firefox7/28/20202060
javascript.builtins.Date.toTemporalInstant 📋Firefox5/27/2025296
javascript.builtins.DisposableStack 📋Firefox7/22/2025240
javascript.builtins.DisposableStack.@@dispose 📋Firefox7/22/2025240
javascript.builtins.DisposableStack.DisposableStack 📋Firefox7/22/2025240
javascript.builtins.DisposableStack.adopt 📋Firefox7/22/2025240
javascript.builtins.DisposableStack.defer 📋Firefox7/22/2025240
javascript.builtins.DisposableStack.dispose 📋Firefox7/22/2025240
javascript.builtins.DisposableStack.disposed 📋Firefox7/22/2025240
javascript.builtins.DisposableStack.move 📋Firefox7/22/2025240
javascript.builtins.DisposableStack.use 📋Firefox7/22/2025240
javascript.builtins.Error.Error.fileName_parameter Firefox11/9/20047800
javascript.builtins.Error.Error.lineNumber_parameter Firefox11/9/20047800
javascript.builtins.Error.columnNumber Firefox11/9/20047800
javascript.builtins.Error.fileName Firefox11/9/20047800
javascript.builtins.Error.lineNumber Firefox11/9/20047800
javascript.builtins.Error.serializable_object 📋Firefox7/26/20221332
Firefox: Version 103 serialized properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox: Version 104 adds serialization of stack in the main thread (window.postMessage() and structuredClone()).Firefox: Version 110 adds serialization of stack in workers (worker.postMessage() and structuredClone()).Firefox for Android: Version 103 serialized properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox for Android: Version 104 adds serialization of stack in the main thread (window.postMessage() and structuredClone()).Firefox for Android: Version 110 adds serialization of stack in workers (worker.postMessage() and structuredClone()).
javascript.builtins.Error.stackTraceLimit Safari4/12/20182898
javascript.builtins.EvalError.serializable_object 📋Firefox7/26/20221332
Firefox: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).Firefox for Android: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox for Android: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox for Android: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).
javascript.builtins.FinalizationRegistry.unregister.symbol_as_target Safari3/27/20231088
javascript.builtins.Function.Function.enforces_trusted_types 📋Safari9/15/2025185
javascript.builtins.Function.displayName Firefox6/5/20125035
javascript.builtins.GeneratorFunction.GeneratorFunction.enforces_trusted_types 📋Safari9/15/2025185
javascript.builtins.InternalError Firefox11/9/20047800
javascript.builtins.InternalError.InternalError Firefox11/9/20047800
javascript.builtins.Intl.Locale.getCalendars 📋Safari9/18/2023913
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 📋Safari9/18/2023913
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 📋Safari9/18/2023913
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 📋Safari9/18/2023913
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 📋Safari9/18/2023913
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 📋Safari9/18/2023913
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 📋Safari9/18/2023913
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.getWeekInfo.returns_minimalDays_property Safari3/14/20221466
javascript.builtins.Intl.PluralRules.PluralRules.options_parameter.options_trailingZeroDisplay_parameter Firefox8/1/2023961
javascript.builtins.Iterator.@@dispose 📋Firefox7/22/2025240
javascript.builtins.Iterator.concat 📋Firefox1/13/202665
javascript.builtins.Iterator.zip 📋Firefox2/24/202623
javascript.builtins.Iterator.zipKeyed 📋Firefox2/24/202623
javascript.builtins.JSON.isRawJSON 📋Firefox2/4/2025408
javascript.builtins.JSON.rawJSON 📋Firefox2/4/2025408
javascript.builtins.Promise.incumbent_settings_object_tracking 📋Firefox11/15/20163411
javascript.builtins.RangeError.serializable_object 📋Firefox7/26/20221332
Firefox: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).Firefox for Android: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox for Android: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox for Android: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).
javascript.builtins.ReferenceError.serializable_object 📋Firefox7/26/20221332
Firefox: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).Firefox for Android: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox for Android: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox for Android: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).
javascript.builtins.SuppressedError 📋Firefox7/22/2025240
javascript.builtins.SuppressedError.SuppressedError 📋Firefox7/22/2025240
javascript.builtins.SuppressedError.error 📋Firefox7/22/2025240
javascript.builtins.SuppressedError.suppressed 📋Firefox7/22/2025240
javascript.builtins.Symbol.asyncDispose 📋Firefox7/22/2025240
Node.js: Only available for fs and stream resources.Node.js: Only available for fs and stream resources.
javascript.builtins.Symbol.dispose 📋Firefox7/22/2025240
Node.js: Only available for fs and stream resources.Node.js: Only available for fs and stream resources.
javascript.builtins.SyntaxError.serializable_object 📋Firefox7/26/20221332
Firefox: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).Firefox for Android: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox for Android: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox for Android: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).
javascript.builtins.Temporal 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.Duration 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.abs 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.add 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.blank 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.compare 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.days 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.from 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.hours 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.microseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.milliseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.minutes 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.months 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.nanoseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.negated 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.round 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.seconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.sign 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.subtract 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.toJSON 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.toLocaleString 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.toString 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.total 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.valueOf 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.weeks 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.with 📋Firefox5/27/2025296
javascript.builtins.Temporal.Duration.years 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.Instant 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.add 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.compare 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.epochMilliseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.epochNanoseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.equals 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.from 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.fromEpochMilliseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.fromEpochNanoseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.round 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.since 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.subtract 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.toJSON 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.toLocaleString 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.toString 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.toZonedDateTimeISO 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.until 📋Firefox5/27/2025296
javascript.builtins.Temporal.Instant.valueOf 📋Firefox5/27/2025296
javascript.builtins.Temporal.Now 📋Firefox5/27/2025296
javascript.builtins.Temporal.Now.instant 📋Firefox5/27/2025296
javascript.builtins.Temporal.Now.plainDateISO 📋Firefox5/27/2025296
javascript.builtins.Temporal.Now.plainDateTimeISO 📋Firefox5/27/2025296
javascript.builtins.Temporal.Now.plainTimeISO 📋Firefox5/27/2025296
javascript.builtins.Temporal.Now.timeZoneId 📋Firefox5/27/2025296
javascript.builtins.Temporal.Now.zonedDateTimeISO 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.PlainDate 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.add 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.calendarId 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.compare 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.day 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.dayOfWeek 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.dayOfYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.daysInMonth 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.daysInWeek 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.daysInYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.equals 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.era 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.eraYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.from 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.inLeapYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.month 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.monthCode 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.monthsInYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.since 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.subtract 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.toJSON 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.toLocaleString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.toPlainDateTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.toPlainMonthDay 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.toPlainYearMonth 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.toString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.toZonedDateTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.until 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.valueOf 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.weekOfYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.with 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.withCalendar 📋Firefox5/27/2025296
Firefox: Calendars islamic, islamic-rgsa and islamic-umalqura are not available. See bug 1950425 and bug 1954138.Firefox for Android: Calendars islamic, islamic-rgsa and islamic-umalqura are not available. See bug 1950425 and bug 1954138.
javascript.builtins.Temporal.PlainDate.year 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDate.yearOfWeek 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.PlainDateTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.add 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.calendarId 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.compare 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.day 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.dayOfWeek 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.dayOfYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.daysInMonth 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.daysInWeek 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.daysInYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.equals 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.era 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.eraYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.from 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.hour 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.inLeapYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.microsecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.millisecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.minute 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.month 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.monthCode 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.monthsInYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.nanosecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.round 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.second 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.since 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.subtract 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.toJSON 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.toLocaleString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.toPlainDate 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.toPlainTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.toString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.toZonedDateTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.until 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.valueOf 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.weekOfYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.with 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.withCalendar 📋Firefox5/27/2025296
Firefox: Calendars islamic, islamic-rgsa and islamic-umalqura are not available. See bug 1950425 and bug 1954138.Firefox for Android: Calendars islamic, islamic-rgsa and islamic-umalqura are not available. See bug 1950425 and bug 1954138.
javascript.builtins.Temporal.PlainDateTime.withPlainTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.year 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainDateTime.yearOfWeek 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.PlainMonthDay 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.calendarId 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.day 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.equals 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.from 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.monthCode 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.toJSON 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.toLocaleString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.toPlainDate 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.toString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.valueOf 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainMonthDay.with 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.PlainTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.add 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.compare 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.equals 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.from 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.hour 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.microsecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.millisecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.minute 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.nanosecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.round 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.second 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.since 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.subtract 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.toJSON 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.toLocaleString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.toString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.until 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.valueOf 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainTime.with 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.PlainYearMonth 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.add 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.calendarId 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.compare 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.daysInMonth 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.daysInYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.equals 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.era 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.eraYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.from 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.inLeapYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.month 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.monthCode 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.monthsInYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.since 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.subtract 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.toJSON 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.toLocaleString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.toPlainDate 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.toString 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.until 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.valueOf 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.with 📋Firefox5/27/2025296
javascript.builtins.Temporal.PlainYearMonth.year 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.ZonedDateTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.add 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.calendarId 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.compare 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.day 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.dayOfWeek 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.dayOfYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.daysInMonth 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.daysInWeek 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.daysInYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.epochMilliseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.epochNanoseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.equals 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.era 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.eraYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.from 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.getTimeZoneTransition 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.hour 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.hoursInDay 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.inLeapYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.microsecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.millisecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.minute 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.month 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.monthCode 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.monthsInYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.nanosecond 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.offset 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.offsetNanoseconds 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.round 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.second 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.since 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.startOfDay 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.subtract 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.timeZoneId 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.toInstant 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.toJSON 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.toLocaleString 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.toPlainDate 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.toPlainDateTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.toPlainTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.toString 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.until 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.valueOf 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.weekOfYear 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.with 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.withCalendar 📋Firefox5/27/2025296
Firefox: Calendars islamic, islamic-rgsa and islamic-umalqura are not available. See bug 1950425 and bug 1954138.Firefox for Android: Calendars islamic, islamic-rgsa and islamic-umalqura are not available. See bug 1950425 and bug 1954138.
javascript.builtins.Temporal.ZonedDateTime.withPlainTime 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.withTimeZone 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.year 📋Firefox5/27/2025296
javascript.builtins.Temporal.ZonedDateTime.yearOfWeek 📋Firefox5/27/2025296
javascript.builtins.TypeError.serializable_object 📋Firefox7/26/20221332
Firefox: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).Firefox for Android: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox for Android: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox for Android: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).
javascript.builtins.URIError.serializable_object 📋Firefox7/26/20221332
Firefox: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).Firefox for Android: Version 103 serializable properties: name, message, cause, fileName, lineNumber and columnNumber.Firefox for Android: Version 104 also serializes stack in the main thread (window.postMessage() and structuredClone()).Firefox for Android: Version 110 also serializes stack in workers (worker.postMessage() and structuredClone()).
javascript.statements.await_using 📋Firefox7/22/2025240
javascript.statements.import.import_attributes.type_css Firefox1/13/202665
javascript.statements.import.worklet_support Firefox6/6/20231017
javascript.statements.using 📋Firefox7/22/2025240