# Is base64-js ESM-only? Can you require() it?

> base64-js@1.5.1 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Base64 encoding/decoding in pure JS

Last verified Sep 9, 2026 against base64-js@1.5.1.

base64-js ships CommonJS only. require("base64-js") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "base64-js" 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("base64-js") 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 base64Js from "base64-js"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 1.5.1 (Nov 11, 2020)
- Module format: CommonJS
- Last CommonJS version: 1.5.1
- TypeScript types: bundled
- Node engines: not declared
- Weekly downloads: 100.7M
- License: MIT

## Runtime test results for base64-js@1.5.1

Installed and executed on Sep 9, 2026 with require("base64-js") from a CommonJS file and import "base64-js" from an ES module.

| Runtime | require("base64-js") | import "base64-js" |
|---|---|---|
| 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 base64-js

ES modules:

```js
import base64Js from "base64-js";
```

CommonJS:

```js
const base64Js = require("base64-js");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (23 versions; the newest 23 shown).

| Versions | Format | First published |
|---|---|---|
| 0.0.1 – 1.5.1 | CommonJS | Nov 26, 2011 |

## Frequently asked

**Is base64-js ESM-only?**

base64-js@1.5.1 is a CommonJS package. base64-js ships CommonJS only. require("base64-js") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "base64-js" 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 base64-js with ES module syntax?**

Yes. import base64Js from "base64-js" 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 base64-js work in Bun?**

Yes. import "base64-js" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does base64-js ship TypeScript types?**

Yes. base64-js bundles its own type declarations; no @types package is needed.

## Links

- [base64-js on npm](https://www.npmjs.com/package/base64-js)
- [Source repository](https://github.com/beatgammit/base64-js)
- [HTML version](https://canirequire.com/package/base64-js/)
- [JSON version](https://canirequire.com/package/base64-js.json)

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