# Is rollup-plugin-postcss ESM-only? Can you require() it?

> rollup-plugin-postcss@4.0.2 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Seamless integration between Rollup and PostCSS

Last verified Sep 9, 2026 against rollup-plugin-postcss@4.0.2.

rollup-plugin-postcss ships CommonJS only. require("rollup-plugin-postcss") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=10. import "rollup-plugin-postcss" 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("rollup-plugin-postcss") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=10.
2. From ES modules use the default import: import rollupPluginPostcss from "rollup-plugin-postcss"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 4.0.2 (Nov 22, 2021)
- Module format: CommonJS
- Last CommonJS version: 4.0.2
- TypeScript types: bundled
- Node engines: >=10
- Weekly downloads: 1.3M
- License: MIT

## Runtime test results for rollup-plugin-postcss@4.0.2

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

| Runtime | require("rollup-plugin-postcss") | import "rollup-plugin-postcss" |
|---|---|---|
| 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 rollup-plugin-postcss

ES modules:

```js
import rollupPluginPostcss from "rollup-plugin-postcss";
```

CommonJS:

```js
const rollupPluginPostcss = require("rollup-plugin-postcss");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (86 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 1.0.2 – 4.0.2 | CommonJS | Jan 10, 2018 |

## Frequently asked

**Is rollup-plugin-postcss ESM-only?**

rollup-plugin-postcss@4.0.2 is a CommonJS package. rollup-plugin-postcss ships CommonJS only. require("rollup-plugin-postcss") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=10. import "rollup-plugin-postcss" 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 rollup-plugin-postcss with ES module syntax?**

Yes. import rollupPluginPostcss from "rollup-plugin-postcss" 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 rollup-plugin-postcss work in Bun?**

Yes. import "rollup-plugin-postcss" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does rollup-plugin-postcss ship TypeScript types?**

Yes. rollup-plugin-postcss bundles its own type declarations; no @types package is needed.

## Links

- [rollup-plugin-postcss on npm](https://www.npmjs.com/package/rollup-plugin-postcss)
- [Source repository](https://github.com/egoist/rollup-plugin-postcss)
- [HTML version](https://canirequire.com/package/rollup-plugin-postcss/)
- [JSON version](https://canirequire.com/package/rollup-plugin-postcss.json)

---

For scripts and AI agents: any package is at https://canirequire.com/package/<name>/index.md (Markdown) or https://canirequire.com/package/<name>.json (JSON); the site index is https://canirequire.com/llms.txt. Fetch the URL directly; no search needed.