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

> postcss-loader@8.2.1 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

PostCSS loader for webpack

Last verified Sep 9, 2026 against postcss-loader@8.2.1.

postcss-loader ships CommonJS only. require("postcss-loader") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 18.12.0. import "postcss-loader" 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("postcss-loader") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 18.12.0.
2. From ES modules use the default import: import postcssLoader from "postcss-loader"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: no types are available for postcss-loader; declare the module yourself if you need them.

## Facts

- Latest: 8.2.1 (Feb 15, 2026)
- Module format: CommonJS
- Last CommonJS version: 8.2.1
- TypeScript types: none
- Node engines: >= 18.12.0
- Weekly downloads: 12.9M
- License: MIT

## Runtime test results for postcss-loader@8.2.1

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

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

ES modules:

```js
import postcssLoader from "postcss-loader";
```

CommonJS:

```js
const postcssLoader = require("postcss-loader");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (88 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 1.2.2 – 8.2.1 | CommonJS | Jan 11, 2017 |

## Frequently asked

**Is postcss-loader ESM-only?**

postcss-loader@8.2.1 is a CommonJS package. postcss-loader ships CommonJS only. require("postcss-loader") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 18.12.0. import "postcss-loader" 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 postcss-loader with ES module syntax?**

Yes. import postcssLoader from "postcss-loader" 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 postcss-loader work in Bun?**

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

**Does postcss-loader ship TypeScript types?**

No. postcss-loader ships no type declarations and there is no @types package for it.

## Links

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

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