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

> react-is@19.2.8 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Brand checking of React Elements.

Last verified Sep 9, 2026 against react-is@19.2.8.

react-is ships CommonJS only. require("react-is") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "react-is" 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("react-is") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun.
2. From ES modules use the default import: import reactIs from "react-is"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: npm install -D @types/react-is

## Facts

- Latest: 19.2.8 (Jul 21, 2026)
- Module format: CommonJS
- Last CommonJS version: 19.2.8
- TypeScript types: @types/react-is
- Node engines: not declared
- Weekly downloads: 316.1M
- License: MIT

## Runtime test results for react-is@19.2.8

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

| Runtime | require("react-is") | import "react-is" |
|---|---|---|
| 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 react-is

ES modules:

```js
import reactIs from "react-is";
```

CommonJS:

```js
const reactIs = require("react-is");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (66 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 16.4.2 – 19.2.8 | CommonJS | Aug 1, 2018 |

## Frequently asked

**Is react-is ESM-only?**

react-is@19.2.8 is a CommonJS package. react-is ships CommonJS only. require("react-is") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "react-is" 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 react-is with ES module syntax?**

Yes. import reactIs from "react-is" 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 react-is work in Bun?**

Yes. import "react-is" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does react-is ship TypeScript types?**

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

## Links

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

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