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

> postcss@8.5.28 ships CommonJS and ESM builds. Dual package — require() works on every Node.js version we test; import works too.

Tool for transforming styles with JS plugins

Last verified Sep 9, 2026 against postcss@8.5.28.

postcss publishes both a CommonJS entry and a native ESM entry (ESM added in 8.0.0). require("postcss") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js ^10 || ^12 || >=14. import "postcss" works alongside it.

## What to do

1. Nothing to change. require("postcss") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js ^10 || ^12 || >=14. import * as postcss from "postcss" works alongside it; use named imports for what the ESM entry exports.
2. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 8.5.28 (Sep 3, 2026)
- Module format: Dual (CommonJS + ESM)
- Last CommonJS version: 8.5.28
- Native ESM since: 8.0.0
- TypeScript types: bundled
- Node engines: ^10 || ^12 || >=14
- Weekly downloads: 249.3M
- License: MIT

## Runtime test results for postcss@8.5.28

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

| Runtime | require("postcss") | import "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 postcss

ES modules:

```js
import * as postcss from "postcss";
```

Namespace import shown because the ESM entry may have no default export; use named imports for what it exports.

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (292 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 8.4.19 – 8.5.28 | Dual (CommonJS + ESM) | Nov 10, 2022 |

## Frequently asked

**Is postcss ESM-only?**

postcss@8.5.28 ships CommonJS and ESM builds. postcss publishes both a CommonJS entry and a native ESM entry (ESM added in 8.0.0). require("postcss") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js ^10 || ^12 || >=14. import "postcss" works alongside it.

**Can I require postcss?**

Yes. postcss ships a CommonJS entry alongside the native ESM entry. require("postcss") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js ^10 || ^12 || >=14.

**Does postcss work in Bun?**

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

**Does postcss ship TypeScript types?**

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

## Links

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

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