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

> bytes@3.1.2 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Utility to parse a string bytes to bytes and vice-versa

Last verified Sep 9, 2026 against bytes@3.1.2.

bytes ships CommonJS only. require("bytes") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.8. import "bytes" 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("bytes") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.8.
2. From ES modules use the default import: import bytes from "bytes"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: npm install -D @types/bytes

## Facts

- Latest: 3.1.2 (Jan 28, 2022)
- Module format: CommonJS
- Last CommonJS version: 3.1.2
- TypeScript types: @types/bytes
- Node engines: >= 0.8
- Weekly downloads: 118.1M
- License: MIT

## Runtime test results for bytes@3.1.2

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

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

ES modules:

```js
import bytes from "bytes";
```

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (18 versions; the newest 18 shown).

| Versions | Format | First published |
|---|---|---|
| 0.0.1 – 3.1.2 | CommonJS | Jun 11, 2012 |

## Frequently asked

**Is bytes ESM-only?**

bytes@3.1.2 is a CommonJS package. bytes ships CommonJS only. require("bytes") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.8. import "bytes" 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 bytes with ES module syntax?**

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

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

**Does bytes ship TypeScript types?**

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

## Links

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

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