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

> microbundle@0.15.1 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Zero-configuration bundler for tiny JS libs, powered by Rollup.

Last verified Sep 9, 2026 against microbundle@0.15.1.

microbundle ships CommonJS only. require("microbundle") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "microbundle" 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("microbundle") 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 microbundle from "microbundle"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: no types are available for microbundle; declare the module yourself if you need them.

## Facts

- Latest: 0.15.1 (Aug 12, 2022)
- Module format: CommonJS
- Last CommonJS version: 0.15.1
- TypeScript types: none
- Node engines: not declared
- Weekly downloads: 115K
- License: MIT

## Runtime test results for microbundle@0.15.1

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

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

ES modules:

```js
import microbundle from "microbundle";
```

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (40 versions; the newest 40 shown).

| Versions | Format | First published |
|---|---|---|
| 0.1.0 – 0.15.1 | CommonJS | Dec 11, 2017 |

## Frequently asked

**Is microbundle ESM-only?**

microbundle@0.15.1 is a CommonJS package. microbundle ships CommonJS only. require("microbundle") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "microbundle" 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 microbundle with ES module syntax?**

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

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

**Does microbundle ship TypeScript types?**

No. microbundle ships no type declarations and there is no @types package for it.

## Links

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

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