core-js-bundle

I highly recommend reading this: So, what's next?

Modular standard library for JavaScript. Includes polyfills for ECMAScript up to 2023: promises, symbols, collections, iterators, typed arrays, many other features, ECMAScript proposals, some cross-platform WHATWG / W3C features and proposals like URL. You can load only required features or use it without global namespace pollution.

Raising funds

core-js isn't backed by a company, so the future of this project depends on you. Become a sponsor or a backer if you are interested in core-js: Open Collective, Patreon, Boosty, Bitcoin ( bc1qlea7544qtsmj2rayg0lthvza9fau63ux0fstcz ), Alipay.

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Example of usage:

import 'core-js/actual';

Promise.resolve(42).then(it => console.log(it)); // => 42

Array.from(new Set([1, 2, 3]).union(new Set([3, 4, 5]))); // => [1, 2, 3, 4, 5]

[1, 2].flatMap(it => [it, it]); // => [1, 1, 2, 2]

(function * (i) { while (true) yield i++; })(1)
  .drop(1).take(5)
  .filter(it => it % 2)
  .map(it => it ** 2)
  .toArray(); // => [9, 25]

structuredClone(new Set([1, 2, 3])); // => new Set([1, 2, 3])

You can load only required features:

import 'core-js/actual/promise';
import 'core-js/actual/set';
import 'core-js/actual/iterator';
import 'core-js/actual/array/from';
import 'core-js/actual/array/flat-map';
import 'core-js/actual/structured-clone';

Promise.resolve(42).then(it => console.log(it)); // => 42

Array.from(new Set([1, 2, 3]).union(new Set([3, 4, 5]))); // => [1, 2, 3, 4, 5]

[1, 2].flatMap(it => [it, it]); // => [1, 1, 2, 2]

(function * (i) { while (true) yield i++; })(1)
  .drop(1).take(5)
  .filter(it => it % 2)
  .map(it => it ** 2)
  .toArray(); // => [9, 25]

structuredClone(new Set([1, 2, 3])); // => new Set([1, 2, 3])

Or use it without global namespace pollution:

import Promise from 'core-js-pure/actual/promise';
import Set from 'core-js-pure/actual/set';
import Iterator from 'core-js-pure/actual/iterator';
import from from 'core-js-pure/actual/array/from';
import flatMap from 'core-js-pure/actual/array/flat-map';
import structuredClone from 'core-js-pure/actual/structured-clone';

Promise.resolve(42).then(it => console.log(it)); // => 42

from(new Set([1, 2, 3]).union(new Set([3, 4, 5]))); // => [1, 2, 3, 4, 5]

flatMap([1, 2], it => [it, it]); // => [1, 1, 2, 2]

Iterator.from(function * (i) { while (true) yield i++; }(1))
  .drop(1).take(5)
  .filter(it => it % 2)
  .map(it => it ** 2)
  .toArray(); // => [9, 25]

structuredClone(new Set([1, 2, 3])); // => new Set([1, 2, 3])

It's a bundled global version, for more info see core-js documentation.

Changelog

3.39.0 - 2024.10.31

• Changes v3.38.1...v3.39.0
• Iterator helpers proposal:
  • Built-ins:
    • Iterator
      • Iterator.from
      • Iterator.prototype.drop
      • Iterator.prototype.every
      • Iterator.prototype.filter
      • Iterator.prototype.find
      • Iterator.prototype.flatMap
      • Iterator.prototype.forEach
      • Iterator.prototype.map
      • Iterator.prototype.reduce
      • Iterator.prototype.some
      • Iterator.prototype.take
      • Iterator.prototype.toArray
      • Iterator.prototype[@@toStringTag]
  • Moved to stable ES, October 2024 TC39 meeting
  • Added es. namespace modules, /es/ and /stable/ namespaces entries
• Promise.try:
  • Built-ins:
    • Promise.try
  • Moved to stable ES, October 2024 TC39 meeting
  • Added es. namespace module, /es/ and /stable/ namespaces entries
  • Fixed /actual|full/promise/try entries for the callback arguments support
• Math.sumPrecise proposal:
  • Built-ins:
    • Math.sumPrecise
  • Moved to stage 3, October 2024 TC39 meeting
  • Added /actual/ namespace entries, unconditional forced replacement changed to feature detection
• Added Iterator sequencing stage 2.7 proposal:
  • Added built-ins:
    • Iterator.concat
• Map upsert stage 2 proposal:
  • Updated to the new API following the October 2024 TC39 meeting
  • Added built-ins:
    • Map.prototype.getOrInsert
    • Map.prototype.getOrInsertComputed
    • WeakMap.prototype.getOrInsert
    • WeakMap.prototype.getOrInsertComputed
• Extractors proposal moved to stage 2, October 2024 TC39 meeting
• Usage of @@species pattern removed from %TypedArray% and ArrayBuffer methods, tc39/ecma262/3450:
  • Built-ins:
    • %TypedArray%.prototype.filter
    • %TypedArray%.prototype.filterReject
    • %TypedArray%.prototype.map
    • %TypedArray%.prototype.slice
    • %TypedArray%.prototype.subarray
    • ArrayBuffer.prototype.slice
• Some other minor improvements
• Compat data improvements:
  • Uint8Array to / from base64 and hex proposal methods marked as shipped from FF133
  • Added NodeJS 23.0 compat data mapping
  • self descriptor is fixed in Deno 1.46.0
  • Added Deno 1.46 and 2.0 compat data mapping
  • Iterator helpers proposal methods marked as shipped from Bun 1.1.31
  • Added Electron 34 and updated Electron 33 compat data mapping
  • Added Opera Android 85 compat data mapping
  • Added Oculus Quest Browser 35 compat data mapping