Blog
Docs
docs-v3
web (default)
web
docs-v3
web-2
Usage
Supported engines and compatibility data
Features
ECMAScript
ECMAScript: Object
ECMAScript: Function
ECMAScript: Error
ECMAScript: Array
ECMAScript: Iterator
ECMAScript: String and RegExp
ECMAScript: Number
ECMAScript: Math
ECMAScript: Date
ECMAScript: Promise
ECMAScript: Symbol
ECMAScript: Collections
ECMAScript: Explicit Resource Management
ECMAScript: Typed Arrays
ECMAScript: Reflect
ECMAScript: JSON
ECMAScript: globalThis
ECMAScript proposals
Finished proposals
globalThis
Relative indexing method
Array.prototype.includes
Array.prototype.flat / Array.prototype.flatMap
Array find from last
Change Array by copy
Array grouping
Array.fromAsync
ArrayBuffer.prototype.transfer and friends
Uint8Array to / from base64 and hex
Error.isError
Explicit Resource Management
Float16 methods
Iterator helpers
Object.values / Object.entries
Object.fromEntries
Object.getOwnPropertyDescriptors
Accessible Object.prototype.hasOwnProperty
String padding
String.prototype.matchAll
String.prototype.replaceAll
String.prototype.trimStart / String.prototype.trimEnd
RegExp s (dotAll) flag
RegExp named capture groups
RegExp escaping
Promise.allSettled
Promise.any
Promise.prototype.finally
Promise.try
Promise.withResolvers
Symbol.asyncIterator for asynchronous iteration
Symbol.prototype.description
Well-formed JSON.stringify
Well-formed unicode strings
New Set methods
Math.sumPrecise
Stage 3 proposals
Iterator sequencing
Map upsert
JSON.parse source text access
Symbol.metadata for decorators metadata proposal
Stage 2.7 proposals
Joint iteration
Stage 2 proposals
AsyncIterator helpers
Iterator.range
Array.isTemplateObject
Number.prototype.clamp
String.dedent
Symbol predicates
Symbol.customMatcher for extractors
Iterator chunking
Stage 1 proposals
Observable
New collections methods
.of and .from methods on collection constructors
compositeKey and compositeSymbol
Array filtering
Array deduplication
DataView get / set Uint8Clamped methods
Number.fromString
String.cooked
String.prototype.codePoints
Symbol.customMatcher for pattern matching
Stage 0 proposals
Function.prototype.demethodize
Function.{ isCallable, isConstructor }
Pre-stage 0 proposals
Reflect metadata
Web standards
self
structuredClone
Base64 utility methods
setTimeout and setInterval
setImmediate
queueMicrotask
URL and URLSearchParams
DOMException
iterable DOM collections
Iteration helpers
Missing polyfills
Playground
Changelog
Theme
docs-v3
web (default)
web
docs-v3
web-2
Usage
Supported engines and compatibility data
Features
ECMAScript
ECMAScript: Object
ECMAScript: Function
ECMAScript: Error
ECMAScript: Array
ECMAScript: Iterator
ECMAScript: String and RegExp
ECMAScript: Number
ECMAScript: Math
ECMAScript: Date
ECMAScript: Promise
ECMAScript: Symbol
ECMAScript: Collections
ECMAScript: Explicit Resource Management
ECMAScript: Typed Arrays
ECMAScript: Reflect
ECMAScript: JSON
ECMAScript: globalThis
ECMAScript proposals
Finished proposals
globalThis
Relative indexing method
Array.prototype.includes
Array.prototype.flat / Array.prototype.flatMap
Array find from last
Change Array by copy
Array grouping
Array.fromAsync
ArrayBuffer.prototype.transfer and friends
Uint8Array to / from base64 and hex
Error.isError
Explicit Resource Management
Float16 methods
Iterator helpers
Object.values / Object.entries
Object.fromEntries
Object.getOwnPropertyDescriptors
Accessible Object.prototype.hasOwnProperty
String padding
String.prototype.matchAll
String.prototype.replaceAll
String.prototype.trimStart / String.prototype.trimEnd
RegExp s (dotAll) flag
RegExp named capture groups
RegExp escaping
Promise.allSettled
Promise.any
Promise.prototype.finally
Promise.try
Promise.withResolvers
Symbol.asyncIterator for asynchronous iteration
Symbol.prototype.description
Well-formed JSON.stringify
Well-formed unicode strings
New Set methods
Math.sumPrecise
Stage 3 proposals
Iterator sequencing
Map upsert
JSON.parse source text access
Symbol.metadata for decorators metadata proposal
Stage 2.7 proposals
Joint iteration
Stage 2 proposals
AsyncIterator helpers
Iterator.range
Array.isTemplateObject
Number.prototype.clamp
String.dedent
Symbol predicates
Symbol.customMatcher for extractors
Iterator chunking
Stage 1 proposals
Observable
New collections methods
.of and .from methods on collection constructors
compositeKey and compositeSymbol
Array filtering
Array deduplication
DataView get / set Uint8Clamped methods
Number.fromString
String.cooked
String.prototype.codePoints
Symbol.customMatcher for pattern matching
Stage 0 proposals
Function.prototype.demethodize
Function.{ isCallable, isConstructor }
Pre-stage 0 proposals
Reflect metadata
Web standards
self
structuredClone
Base64 utility methods
setTimeout and setInterval
setImmediate
queueMicrotask
URL and URLSearchParams
DOMException
iterable DOM collections
Iteration helpers
Missing polyfills
globalThis
let globalThis: GlobalThisValue;
CommonJS entry points
core-js/proposals/global-this
CommonJS entry points