# Is object-assign ESM-only? Can you require() it?

> object-assign@4.1.1 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

ES2015 `Object.assign()` ponyfill

Last verified Sep 9, 2026 against object-assign@4.1.1.

object-assign ships CommonJS only. require("object-assign") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=0.10.0. import "object-assign" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

## What to do

1. require("object-assign") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=0.10.0.
2. From ES modules use the default import: import objectAssign from "object-assign"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: npm install -D @types/object-assign

## Facts

- Latest: 4.1.1 (Jan 16, 2017)
- Module format: CommonJS
- Last CommonJS version: 4.1.1
- TypeScript types: @types/object-assign
- Node engines: >=0.10.0
- Weekly downloads: 149.4M
- License: MIT

## Runtime test results for object-assign@4.1.1

Installed and executed on Sep 9, 2026 with require("object-assign") from a CommonJS file and import "object-assign" from an ES module.

| Runtime | require("object-assign") | import "object-assign" |
|---|---|---|
| Node.js 18 | works | works |
| Node.js 20 | works | works |
| Node.js 22 | works | works |
| Node.js 24 | works | works |
| Node.js 26 | works | works |
| Bun 1.4.0 | works | works |

## How to import object-assign

ES modules:

```js
import objectAssign from "object-assign";
```

CommonJS:

```js
const objectAssign = require("object-assign");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (17 versions; the newest 17 shown).

| Versions | Format | First published |
|---|---|---|
| 0.1.0 – 4.1.1 | CommonJS | Feb 2, 2014 |

## Frequently asked

**Is object-assign ESM-only?**

object-assign@4.1.1 is a CommonJS package. object-assign ships CommonJS only. require("object-assign") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=0.10.0. import "object-assign" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

**Can I import object-assign with ES module syntax?**

Yes. import objectAssign from "object-assign" works in Node.js and Bun because they support importing CommonJS modules. Named imports work only when Node.js can statically detect the exports.

**Does object-assign work in Bun?**

Yes. import "object-assign" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does object-assign ship TypeScript types?**

Not bundled. Install the community types with "npm install -D @types/object-assign".

## Links

- [object-assign on npm](https://www.npmjs.com/package/object-assign)
- [Source repository](https://github.com/sindresorhus/object-assign)
- [HTML version](https://canirequire.com/package/object-assign/)
- [JSON version](https://canirequire.com/package/object-assign.json)

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