# Is @sindresorhus/is ESM-only? Can you require() it?

> @sindresorhus/is@8.1.0 is ESM-only. ESM-only since 5.0.1 — last CommonJS version is 4.6.0.

Type check values

Last verified Sep 9, 2026 against @sindresorhus/is@8.1.0.

@sindresorhus/is dropped its CommonJS build in 5.0.1 (June 2022). The last version with a plain require()-able CommonJS entry is 4.6.0, published Feb 27, 2022; it declares support for Node.js >=10.

On Node.js 22.12+ and newer (@sindresorhus/is@8.1.0 declares Node.js >=22), require("@sindresorhus/is") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 22, 24 and 26. Node.js 18 has no require(esm), and @sindresorhus/is@8.1.0 declares Node.js >=22, so 18 is outside its supported range anyway.

@sindresorhus/is@8.1.0 declares engines ">=22", so Node.js 18, 20 are outside its supported range regardless of module format.

## What to do

1. On Node.js 22.12+ and newer (@sindresorhus/is@8.1.0 declares Node.js >=22), require("@sindresorhus/is") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 22, 24 and 26.
2. From a CommonJS file, use a dynamic import inside an async function: const is = await import("@sindresorhus/is"). That works on every Node.js version the package supports (>=22).
3. If you need a synchronous require() or run Node.js 18: npm install @sindresorhus/is@4.6.0, the last CommonJS release (published Feb 27, 2022); it declares Node.js >=10.
4. @sindresorhus/is@8.1.0 declares engines ">=22", so Node.js 18, 20 are unsupported regardless: upgrade Node.js or pin an older release.
5. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 8.1.0 (May 11, 2026)
- Module format: ESM-only
- Last CommonJS version: 4.6.0
- ESM-only since: 5.0.1 (Jun 11, 2022)
- TypeScript types: bundled
- Node engines: >=22
- Weekly downloads: 45.3M
- License: MIT

## Runtime test results for @sindresorhus/is@8.1.0

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

| Runtime | require("@sindresorhus/is") | import "@sindresorhus/is" |
|---|---|---|
| Node.js 18 | fails (ERR_REQUIRE_ESM) | fails (SyntaxError) |
| 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 @sindresorhus/is

ES modules:

```js
import * as is from "@sindresorhus/is";
```

Namespace import shown because the ESM entry may have no default export; use named imports for what it exports.

CommonJS:

```js
// Node.js 22.12+ and newer (verified):
const is = require("@sindresorhus/is");

// Any Node.js version the package supports (>=22), from an async function:
async function main() {
  const is = await import("@sindresorhus/is");
}

// Or pin the last CommonJS release (declares Node.js >=10):
// npm install @sindresorhus/is@4.6.0
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (63 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 5.0.1 – 8.1.0 | ESM-only | Jun 11, 2022 |
| 5.0.0 | No JS entry point | Jun 11, 2022 |
| 0.3.0 – 4.6.0 | CommonJS | Oct 11, 2017 |

## Frequently asked

**Is @sindresorhus/is ESM-only?**

@sindresorhus/is@8.1.0 is ESM-only. @sindresorhus/is dropped its CommonJS build in 5.0.1 (June 2022). The last version with a plain require()-able CommonJS entry is 4.6.0, published Feb 27, 2022; it declares support for Node.js >=10.

**Which version of @sindresorhus/is still supports CommonJS / require()?**

4.6.0 is the last version of @sindresorhus/is with a CommonJS build; it declares Node.js >=10. Install it with "npm install @sindresorhus/is@4.6.0". Every version from 5.0.1 on is ESM-only.

**How do I use @sindresorhus/is from a CommonJS file?**

From a CommonJS file, use a dynamic import inside an async function: const is = await import("@sindresorhus/is"). That works on every Node.js version the package supports (>=22). On Node.js 22.12+ and newer (@sindresorhus/is@8.1.0 declares Node.js >=22), require("@sindresorhus/is") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 22, 24 and 26. Alternatively pin @sindresorhus/is@4.6.0 (declares Node.js >=10).

**Does @sindresorhus/is work in Bun?**

Yes. import "@sindresorhus/is" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does @sindresorhus/is ship TypeScript types?**

Yes. @sindresorhus/is bundles its own type declarations; no @types package is needed.

## Links

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

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