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

> which@7.0.0 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Like which(1) unix command. Find the first instance of an executable in the PATH.

Last verified Sep 9, 2026 against which@7.0.0.

which ships CommonJS only. require("which") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js ^22.22.2 || ^24.15.0 || >=26.0.0. import "which" 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("which") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js ^22.22.2 || ^24.15.0 || >=26.0.0.
2. From ES modules use the default import: import which from "which"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: npm install -D @types/which

## Facts

- Latest: 7.0.0 (May 8, 2026)
- Module format: CommonJS
- Last CommonJS version: 7.0.0
- TypeScript types: @types/which
- Node engines: ^22.22.2 || ^24.15.0 || >=26.0.0
- Weekly downloads: 290.2M
- License: ISC

## Runtime test results for which@7.0.0

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

| Runtime | require("which") | import "which" |
|---|---|---|
| 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 which

ES modules:

```js
import which from "which";
```

CommonJS:

```js
const which = require("which");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (37 versions; the newest 37 shown).

| Versions | Format | First published |
|---|---|---|
| 1.0.0 – 7.0.0 | CommonJS | Aug 7, 2011 |

## Frequently asked

**Is which ESM-only?**

which@7.0.0 is a CommonJS package. which ships CommonJS only. require("which") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js ^22.22.2 || ^24.15.0 || >=26.0.0. import "which" 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 which with ES module syntax?**

Yes. import which from "which" 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 which work in Bun?**

Yes. import "which" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does which ship TypeScript types?**

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

## Links

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

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