Time to Stable

For a given set of browsers, what APIs are in all of them and how many days it take for the API to land in the first browser to the last.

Example Comparisons
Browsers
Features

Summary

A count of the number of APIs that landed in A first and B last.
Last in EdgeLast in Safari
First in Edge 28
First in Safari 33

Average time for an API to become available across Edge and Safari

61 APIs took an average of 219.39 days to become available to use.

API breakdown:

Average time to landing by year of first landing

If a feature landed in the earliest browser in 20XX it took Y days on average to become available in the last browser (when considering Edge and Safari). TTA (time to available).
WebAssembly APIsWebAssembly TTA
2017 30121.73
2018 21028.00
2020 10283.10
2021 10111.80
2022 1990.00
2023 5447.00
2024 1421.00
2025 240.00

The Tortoise and the Hare

There is a natural tension on the web with respect to browser engines. Every engine has their own set of priorities which define the level of investment that they choose to make and on which areas they choose to make it.

A developer naturally wants their experiences to be available to the widest audience possible and these differing priorities create an unevenness on the platform (a lumpiness) making it harder for developers to build experiences that work everywhere.

This section highlights where browsers are pushing and pulling on the platform.

Sprinters

This table is designed to show which browsers are pushing on the platform the most.

Adding features to quickly is not always desired because developers are unlikely to adopt those features in their sites or apps.

For a given year, if a feature landed in Browser X first, how many days it take on average to be available in Edge and Safari. TTA (time to available).
Year WebAssemblyWebAssembly TTA
2017
  Safari 2828.00
  Edge 21434.00
2018
  Edge 21028.00
2020
  Edge 9292.44
  Safari 1199.00
2021
  Edge 9121.44
  Safari 125.00
2022
  Safari 1990.00
2023
  Edge 5447.00
2024
  Edge 1421.00
2025
  Safari 240.00

Plodders

This table is designed to show which browsers are pulling on the platform the most.

For a feature that first landed in year X, how many days did it take on average for the last browser to catch up across Edge and Safari. TTA (time to available).
Year WebAssembly countWebAssembly TTA
2017
  Edge 2828.00
  Safari 21434.00
2018
  Safari 21028.00
2020
  Safari 9292.44
  Edge 1199.00
2021
  Safari 9121.44
  Edge 125.00
2022
  Edge 1990.00
2023
  Safari 5447.00
2024
  Safari 1421.00
2025
  Edge 240.00

Stable APIs

Below is a list of features that are in Edge and Safari

Raw Data

Quick Links:

WebAssembly Data

API First Browser Date Last Browser Date Days Notes
webassembly.BigInt-to-i64-integration 📋Edge8/27/2020 Safari4/26/2021242
webassembly.api 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.CompileError 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.CompileError.CompileError 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Exception 📋Edge10/21/2021 Safari12/13/202153
webassembly.api.Exception.Exception 📋Edge10/21/2021 Safari12/13/202153
webassembly.api.Exception.Exception.options_parameter_traceStack Edge10/21/2021 Safari12/13/202153
webassembly.api.Exception.getArg 📋Edge10/21/2021 Safari12/13/202153
webassembly.api.Exception.is 📋Edge10/21/2021 Safari12/13/202153
webassembly.api.Global 📋Edge1/15/2020 Safari3/24/202069
webassembly.api.Global.Global 📋Edge1/15/2020 Safari3/24/202069
Chrome: Constructing a Global with a value of v128 produces a TypeError.Chrome Android: Constructing a Global with a value of v128 produces a TypeError.Deno: Constructing a Global with a value of v128 produces a TypeError.Edge: Constructing a Global with a value of v128 produces a TypeError.Node.js: Constructing a Global with a value of v128 produces a TypeError.Quest Browser: Constructing a Global with a value of v128 produces a TypeError.Opera: Constructing a Global with a value of v128 produces a TypeError.Opera Android: Constructing a Global with a value of v128 produces a TypeError.Samsung Internet: Constructing a Global with a value of v128 produces a TypeError.WebView Android: Constructing a Global with a value of v128 produces a TypeError.
webassembly.api.Global.value 📋Edge1/15/2020 Safari3/24/202069
webassembly.api.Global.valueOf 📋Edge1/15/2020 Safari3/24/202069
webassembly.api.Instance 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Instance.Instance 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Instance.exports 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.JSTag_static 📋Edge7/21/2023 Safari3/31/2025619
webassembly.api.LinkError 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.LinkError.LinkError 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Memory 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Memory.Memory 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Memory.Memory.shared 📋Edge1/15/2020 Safari12/13/2021698
Safari: Shared WebAssembly.Memory is gated behind COOP/COEP. For more detail, read Making your website "cross-origin isolated" using COOP and COEP.Safari on iOS: Shared WebAssembly.Memory is gated behind COOP/COEP. For more detail, read Making your website "cross-origin isolated" using COOP and COEP.WebView on iOS: Shared WebAssembly.Memory is gated behind COOP/COEP. For more detail, read Making your website "cross-origin isolated" using COOP and COEP.
webassembly.api.Memory.buffer 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Memory.grow 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Memory.toFixedLengthBuffer 📋Safari12/12/2025 Edge1/21/202640
webassembly.api.Memory.toResizableBuffer 📋Safari12/12/2025 Edge1/21/202640
webassembly.api.Module 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Module.Module 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Module.customSections_static 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Module.exports_static 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Module.imports_static 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.RuntimeError 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.RuntimeError.RuntimeError 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Table 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Table.Table 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Table.get 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Table.grow 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Table.length 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Table.set 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.Tag 📋Edge10/21/2021 Safari12/13/202153
webassembly.api.Tag.Tag 📋Edge10/21/2021 Safari12/13/202153
webassembly.api.compileStreaming_static 📋Edge10/17/2017 Safari9/20/20211434
webassembly.api.compile_static 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.instantiateStreaming_static 📋Edge10/17/2017 Safari9/20/20211434
webassembly.api.instantiate_static 📋Safari9/19/2017 Edge10/17/201728
webassembly.api.validate_static 📋Safari9/19/2017 Edge10/17/201728
webassembly.branch-hinting 📋Safari9/12/2022 Edge5/29/2025990
webassembly.bulk-memory-operations 📋Edge1/15/2020 Safari10/25/2021649
webassembly.exception-handling 📋Edge10/21/2021 Safari12/13/202153
webassembly.extended-constant-expressions 📋Edge6/2/2023 Safari3/5/2024277
webassembly.fixed-width-SIMD 📋Edge5/27/2021 Safari3/27/2023669
webassembly.garbage-collection 📋Edge11/2/2023 Safari12/11/2024405
webassembly.jsStringBuiltins 📋Edge10/17/2024 Safari12/12/2025421
webassembly.multi-value 📋Safari3/24/2020 Edge10/9/2020199
webassembly.mutable-globals 📋Edge1/15/2020 Safari3/24/202069
webassembly.non-trapping-float-to-int-conversions 📋Edge10/2/2018 Safari10/25/20211119
webassembly.reference-types 📋Safari10/25/2021 Edge11/19/202125
webassembly.sign-extension-operations 📋Edge10/2/2018 Safari4/26/2021937
webassembly.tail-calls 📋Edge4/6/2023 Safari12/11/2024615
webassembly.threads-and-atomics 📋Edge1/15/2020 Safari12/13/2021698
webassembly.typedFunctionReferences 📋Edge11/2/2023 Safari9/16/2024319