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

> postcss-nested@8.0.1 is ESM-only. ESM-only since 8.0.0 — last CommonJS version is 7.0.2.

PostCSS plugin to unwrap nested rules like how Sass does it

Last verified Sep 9, 2026 against postcss-nested@8.0.1.

postcss-nested dropped its CommonJS build in 8.0.0 (July 2026). The last version with a plain require()-able CommonJS entry is 7.0.2, published Nov 1, 2024; it declares support for Node.js >=18.0.

On Node.js 22.12+ and newer (postcss-nested@8.0.1 declares Node.js ^22.0.0 || ^24.0.0 || >= 26.0.0), require("postcss-nested") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 22, 24 and 26. Node.js 18 has no require(esm), and postcss-nested@8.0.1 declares Node.js ^22.0.0 || ^24.0.0 || >= 26.0.0, so 18 is outside its supported range anyway.

postcss-nested@8.0.1 declares engines "^22.0.0 || ^24.0.0 || >= 26.0.0", so Node.js 18, 20 are outside its supported range regardless of module format.

## What to do

1. On Node.js 22.12+ and newer (postcss-nested@8.0.1 declares Node.js ^22.0.0 || ^24.0.0 || >= 26.0.0), require("postcss-nested") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 22, 24 and 26.
2. From a CommonJS file, use a dynamic import inside an async function: const postcssNested = await import("postcss-nested"). That works on every Node.js version the package supports (^22.0.0 || ^24.0.0 || >= 26.0.0).
3. If you need a synchronous require() or run Node.js 18: npm install postcss-nested@7.0.2, the last CommonJS release (published Nov 1, 2024); it declares Node.js >=18.0.
4. postcss-nested@8.0.1 declares engines "^22.0.0 || ^24.0.0 || >= 26.0.0", so Node.js 18, 20 are unsupported regardless: upgrade Node.js or pin an older release.
5. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 8.0.1 (Aug 2, 2026)
- Module format: ESM-only
- Last CommonJS version: 7.0.2
- ESM-only since: 8.0.0 (Jul 29, 2026)
- TypeScript types: bundled
- Node engines: ^22.0.0 || ^24.0.0 || >= 26.0.0
- Weekly downloads: 35.4M
- License: MIT

## Runtime test results for postcss-nested@8.0.1

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

| Runtime | require("postcss-nested") | import "postcss-nested" |
|---|---|---|
| Node.js 18 | fails (ERR_REQUIRE_ESM) | 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-nested

ES modules:

```js
import * as postcssNested from "postcss-nested";
```

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

CommonJS:

```js
// Node.js 22.12+ and newer (verified):
const postcssNested = require("postcss-nested");

// Any Node.js version the package supports (^22.0.0 || ^24.0.0 || >= 26.0.0), from an async function:
async function main() {
  const postcssNested = await import("postcss-nested");
}

// Or pin the last CommonJS release (declares Node.js >=18.0):
// npm install postcss-nested@7.0.2
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (41 versions; the newest 41 shown).

| Versions | Format | First published |
|---|---|---|
| 8.0.0 – 8.0.1 | ESM-only | Jul 29, 2026 |
| 0.1.0 – 7.0.2 | CommonJS | Nov 11, 2014 |

## Frequently asked

**Is postcss-nested ESM-only?**

postcss-nested@8.0.1 is ESM-only. postcss-nested dropped its CommonJS build in 8.0.0 (July 2026). The last version with a plain require()-able CommonJS entry is 7.0.2, published Nov 1, 2024; it declares support for Node.js >=18.0.

**Which version of postcss-nested still supports CommonJS / require()?**

7.0.2 is the last version of postcss-nested with a CommonJS build; it declares Node.js >=18.0. Install it with "npm install postcss-nested@7.0.2". Every version from 8.0.0 on is ESM-only.

**How do I use postcss-nested from a CommonJS file?**

From a CommonJS file, use a dynamic import inside an async function: const postcssNested = await import("postcss-nested"). That works on every Node.js version the package supports (^22.0.0 || ^24.0.0 || >= 26.0.0). On Node.js 22.12+ and newer (postcss-nested@8.0.1 declares Node.js ^22.0.0 || ^24.0.0 || >= 26.0.0), require("postcss-nested") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 22, 24 and 26. Alternatively pin postcss-nested@7.0.2 (declares Node.js >=18.0).

**Does postcss-nested work in Bun?**

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

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

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

## Links

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

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