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 EdgeNot in Safari
In Edge 27
In Safari 13

Unstable APIs

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

Raw Data

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JS Data

API First Browser Date Days in Limbo Notes
javascript.builtins.Atomics.pause 📋Edge2/6/2025542
javascript.builtins.DataView.getFloat16 📋Safari12/11/2024599
javascript.builtins.DataView.setFloat16 📋Safari12/11/2024599
javascript.builtins.Error.cause.displayed_in_console Edge5/17/2024807
javascript.builtins.Error.serializable_object 📋Edge1/15/20202391
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.EvalError.serializable_object 📋Edge1/15/20202391
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.Float16Array 📋Safari12/11/2024599
javascript.builtins.Float16Array.Float16Array 📋Safari12/11/2024599
javascript.builtins.Intl.PluralRules.PluralRules.options_parameter.options_roundingIncrement_parameter Safari12/11/2023965
javascript.builtins.Iterator.Iterator 📋Edge2/23/2024891
javascript.builtins.Iterator.drop 📋Edge2/23/2024891
javascript.builtins.Iterator.every 📋Edge2/23/2024891
javascript.builtins.Iterator.filter 📋Edge2/23/2024891
javascript.builtins.Iterator.find 📋Edge2/23/2024891
javascript.builtins.Iterator.flatMap 📋Edge2/23/2024891
javascript.builtins.Iterator.forEach 📋Edge2/23/2024891
javascript.builtins.Iterator.from 📋Edge2/23/2024891
javascript.builtins.Iterator.map 📋Edge2/23/2024891
javascript.builtins.Iterator.reduce 📋Edge2/23/2024891
javascript.builtins.Iterator.some 📋Edge2/23/2024891
javascript.builtins.Iterator.take 📋Edge2/23/2024891
javascript.builtins.Iterator.toArray 📋Edge2/23/2024891
javascript.builtins.JSON.isRawJSON 📋Edge6/2/20231157
javascript.builtins.JSON.parse.reviver_parameter_context_argument 📋Edge6/2/20231157
javascript.builtins.JSON.rawJSON 📋Edge6/2/20231157
javascript.builtins.Math.f16round 📋Safari12/11/2024599
javascript.builtins.RangeError.serializable_object 📋Edge1/15/20202391
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 📋Edge1/15/20202391
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.RegExp.escape 📋Safari12/11/2024599
javascript.builtins.SyntaxError.serializable_object 📋Edge1/15/20202391
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.TypeError.serializable_object 📋Edge1/15/20202391
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 📋Edge1/15/20202391
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.Uint8Array.fromBase64 📋Safari12/11/2024599
javascript.builtins.Uint8Array.fromHex 📋Safari12/11/2024599
javascript.builtins.Uint8Array.setFromBase64 📋Safari12/11/2024599
javascript.builtins.Uint8Array.setFromHex 📋Safari12/11/2024599
javascript.builtins.Uint8Array.toBase64 📋Safari12/11/2024599
javascript.builtins.Uint8Array.toHex 📋Safari12/11/2024599
javascript.regular_expressions.modifier 📋Edge5/17/2024807
javascript.statements.import.import_attributes.type_css Edge3/22/2024863