# core-js-builder

> core-js builder

Latest version **3.50.0** (published 2026-08-05) · MIT license · 0 weekly downloads

## Install

```sh
npm install core-js-builder
pnpm add core-js-builder
yarn add core-js-builder
bun add core-js-builder
```

## Health

**Score 60/100 (C)** — status: active.

Positive: has types; no vulnerabilities; recently updated; high maintenance score.

Warnings: low downloads; no esm support.

## Facts

| | |
|---|---|
| Version | 3.50.0 |
| Published | 2026-08-05 |
| First published | 2015-12-18 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | CommonJS |
| Node | >=8.9.0 |
| Dependencies | 4 |
| Unpacked size | 9.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Author | Denis Pushkarev |
| Maintainers | zloirock |

## Links

- npm: https://www.npmjs.com/package/core-js-builder
- Repository: https://github.com/zloirock/core-js
- Homepage: https://core-js.io
- Issues: https://github.com/zloirock/core-js/issues
- Funding: https://opencollective.com/core-js
- npm.io page: https://npm.io/package/core-js-builder

## Dependencies (4)

- [mkdirp](https://npm.io/package/mkdirp.md) >=0.5.6 <1
- [core-js](https://npm.io/package/core-js.md) 3.50.0
- [webpack](https://npm.io/package/webpack.md) >=4.47.0 <5
- [core-js-compat](https://npm.io/package/core-js-compat.md) 3.50.0

## Recent versions

- 3.50.0 (latest) — 2026-08-05
- 3.0.0-beta.20 (beta) — 2019-03-17
- 3.0.0-alpha.4 (alpha) — 2018-04-09
- 3.49.0 — 2026-03-16
- 3.48.0 — 2026-01-21
- 3.47.0 — 2025-11-18
- 3.46.0 — 2025-10-09
- 3.45.1 — 2025-08-20
- 3.45.0 — 2025-08-04
- 3.44.0 — 2025-07-07
- 3.43.0 — 2025-06-09
- 3.42.0 — 2025-04-29
- 3.41.0 — 2025-03-01
- 3.40.0 — 2025-01-07
- 3.39.0 — 2024-10-31
- … 187 more at https://npm.io/package/core-js-builder/versions

## README

![logo](https://user-images.githubusercontent.com/2213682/146607186-8e13ddef-26a4-4ebf-befd-5aac9d77c090.png)

<div align="center">

[![fundraising](https://opencollective.com/core-js/all/badge.svg?label=fundraising)](https://opencollective.com/core-js) [![PRs welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](https://github.com/zloirock/core-js/blob/master/CONTRIBUTING.md) [![version](https://img.shields.io/npm/v/core-js-builder.svg)](https://www.npmjs.com/package/core-js-builder)

</div>

**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)**
---

For some cases could be useful to exclude some [`core-js`](https://core-js.io) features or generate a polyfill for target engines. This API helps conditionally include or exclude certain parts of [`core-js`](https://core-js.io) and build for targets. `modules`, `exclude` and `targets` options are specified in [the `core-js-compat` format](https://github.com/zloirock/core-js/tree/master/packages/core-js-compat).

```js
import builder from 'core-js-builder';

const bundle = await builder({
  // entry / module / namespace / an array of them, by default - all `core-js` modules
  modules: ['core-js/actual', /^esnext\.reflect\./],
  // a blacklist of entries / modules / namespaces, by default - empty list
  exclude: [/^es\.math\./, 'es.number.constructor'],
  // optional browserslist or core-js-compat format query
  targets: '> 0.5%, not dead, ie 9-11',
  // shows summary for the bundle, disabled by default
  summary: {
    // in the console, you could specify required parts or set `true` for enable all of them
    console: { size: true, modules: false },
    // in the comment in the target file, similarly to `summary.console`
    comment: { size: false, modules: true },
  },
  // output format, 'bundle' by default, can be 'cjs' or 'esm', and in this case
  // the result will not be bundled and will contain imports of required modules
  format: 'bundle',
  // optional target filename, if it's missed a file will not be created
  filename: PATH_TO_MY_COREJS_BUNDLE,
});
```

ℹ️ When using TypeScript, make sure to set `esModuleInterop` to `true`.

---
_Source: https://npm.io/package/core-js-builder · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._