[](https://opencollective.com/core-js) [](https://github.com/zloirock/core-js/blob/master/CONTRIBUTING.md) [](https://www.npmjs.com/package/core-js-compat) [](https://npm-stat.com/charts.html?package=core-js&package=core-js-pure&package=core-js-compat&from=2014-11-18)
**I highly recommend reading this: [So, what's next?](https://github.com/zloirock/core-js/blob/master/docs/2023-02-14-so-whats-next.md)**
---
[`core-js-compat` package](https://github.com/zloirock/core-js/tree/master/packages/core-js-compat) contains data about the necessity of [`core-js`](https://github.com/zloirock/core-js) modules and API for getting a list of required core-js modules by browserslist query.
```js
import compat from 'core-js-compat';
const {
list, // array of required modules
targets, // object with targets for each module
} = compat({
targets: '> 1%', // browserslist query or object of minimum environment versions to support, see below
modules: [ // optional list / filter of modules - regex, sting or an array of them:
'core-js/actual', // - an entry point
'esnext.array.unique-by', // - a module name (or just a start of a module name)
/^web\./, // - regex that a module name must satisfy
],
exclude: [ // optional list / filter of modules to exclude, the signature is similar to `modules` option
'web.atob',
],
version: '3.31', // used `core-js` version, by default - the latest
inverse: false, // inverse of the result - shows modules that are NOT required for the target environment
});
console.log(targets);
/* =>
{
'es.error.cause': { ios: '14.5-14.8' },
'es.aggregate-error.cause': { ios: '14.5-14.8' },
'es.array.at': { ios: '14.5-14.8' },
'es.array.find-last': { firefox: '100', ios: '14.5-14.8' },
'es.array.find-last-index': { firefox: '100', ios: '14.5-14.8' },
'es.array.includes': { firefox: '100' },
'es.array.push': { chrome: '100', edge: '101', ios: '14.5-14.8', safari: '15.4' },
'es.array.unshift': { ios: '14.5-14.8', safari: '15.4' },
'es.object.has-own': { ios: '14.5-14.8' },
'es.regexp.flags': { chrome: '100', edge: '101' },
'es.string.at-alternative': { ios: '14.5-14.8' },
'es.typed-array.at': { ios: '14.5-14.8' },
'es.typed-array.find-last': { firefox: '100', ios: '14.5-14.8' },
'es.typed-array.find-last-index': { firefox: '100', ios: '14.5-14.8' },
'esnext.array.group': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.array.group-by': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.array.group-by-to-map': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.array.group-to-map': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.array.to-reversed': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.array.to-sorted': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.array.to-spliced': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.array.unique-by': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.array.with': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.typed-array.to-reversed': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.typed-array.to-sorted': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.typed-array.to-spliced': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'esnext.typed-array.with': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'web.dom-exception.stack': { chrome: '100', edge: '101', ios: '14.5-14.8', safari: '15.4' },
'web.immediate': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' },
'web.structured-clone': { chrome: '100', edge: '101', firefox: '100', ios: '14.5-14.8', safari: '15.4' }
}
*/
```
### `targets` option
`targets` could be [a `browserslist` query](https://github.com/browserslist/browserslist) or a targets object that specifies minimum environment versions to support:
```js
// browserslist query:
'defaults, not IE 11, maintained node versions'
// object (sure, all those fields optional):
{
android: '4.0', // Android WebView version
bun: '0.1.2', // Bun version
chrome: '38', // Chrome version
'chrome-android': '18', // Chrome for Android version
deno: '1.12', // Deno version
edge: '13', // Edge version
electron: '5.0', // Electron framework version
firefox: '15', // Firefox version
'firefox-android': '4', // Firefox for Android version
hermes: '0.11', // Hermes version
ie: '8', // Internet Explorer version
ios: '13.0', // iOS Safari version
node: 'current', // NodeJS version, you can use 'current' for set it to currently used
opera: '12', // Opera version
'opera-android': '7', // Opera for Android version
phantom: '1.9', // PhantomJS headless browser version
quest: '5.0', // Meta Quest Browser version
'react-native': '0.70', // React Native version (default Hermes engine)
rhino: '1.7.13', // Rhino engine version
safari: '14.0', // Safari version
samsung: '14.0', // Samsung Internet version
esmodules: true, // That option set target to minimum supporting ES Modules versions of all browsers
browsers: '> 0.25%', // Browserslist query or object with target browsers
}
```
### Additional API:
```js
// equals of of the method from the example above
require('core-js-compat/compat')({ targets, modules, version }); // => { list: Array, targets: { [ModuleName]: { [EngineName]: EngineVersion } } }
// or
require('core-js-compat').compat({ targets, modules, version }); // => { list: Array, targets: { [ModuleName]: { [EngineName]: EngineVersion } } }
// full compat data:
require('core-js-compat/data'); // => { [ModuleName]: { [EngineName]: EngineVersion } }
// or
require('core-js-compat').data; // => { [ModuleName]: { [EngineName]: EngineVersion } }
// map of modules by `core-js` entry points:
require('core-js-compat/entries'); // => { [EntryPoint]: Array }
// or
require('core-js-compat').entries; // => { [EntryPoint]: Array }
// full list of modules:
require('core-js-compat/modules'); // => Array
// or
require('core-js-compat').modules; // => Array
// the subset of modules which available in the passed `core-js` version:
require('core-js-compat/get-modules-list-for-target-version')('3.31'); // => Array
// or
require('core-js-compat').getModulesListForTargetVersion('3.31'); // => Array
```
If you wanna help to improve this data, you could take a look at the related section of [`CONTRIBUTING.md`](https://github.com/zloirock/core-js/blob/master/CONTRIBUTING.md#how-to-update-core-js-compat-data). The visualization of compatibility data and the browser tests runner is available [here](http://zloirock.github.io/core-js/compat/), the example:
