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

> postcss-preset-env@11.5.2 is ESM-only. ESM-only since 11.0.0 — last CommonJS version is 10.6.1.

Convert modern CSS into something browsers understand

Last verified Sep 9, 2026 against postcss-preset-env@11.5.2.

postcss-preset-env dropped its CommonJS build in 11.0.0 (January 2026). The last version with a plain require()-able CommonJS entry is 10.6.1, published Jan 10, 2026; it declares support for Node.js >=18.

On Node.js 20.19+, 22.12+ and newer, require("postcss-preset-env") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26. Node.js 18 has no require(esm), and postcss-preset-env@11.5.2 declares Node.js >=20.19.0, so 18 is outside its supported range anyway.

postcss-preset-env@11.5.2 declares engines ">=20.19.0", so Node.js 18 is outside its supported range regardless of module format.

## What to do

1. On Node.js 20.19+, 22.12+ and newer, require("postcss-preset-env") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26.
2. From a CommonJS file, use a dynamic import inside an async function: const postcssPresetEnv = await import("postcss-preset-env"). That works on every Node.js version the package supports (>=20.19.0).
3. If you need a synchronous require() or run Node.js 18: npm install postcss-preset-env@10.6.1, the last CommonJS release (published Jan 10, 2026); it declares Node.js >=18.
4. postcss-preset-env@11.5.2 declares engines ">=20.19.0", so Node.js 18 is unsupported regardless: upgrade Node.js or pin an older release.
5. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 11.5.2 (Sep 6, 2026)
- Module format: ESM-only
- Last CommonJS version: 10.6.1
- ESM-only since: 11.0.0 (Jan 14, 2026)
- TypeScript types: bundled
- Node engines: >=20.19.0
- Weekly downloads: 6.6M
- License: MIT-0

## Runtime test results for postcss-preset-env@11.5.2

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

| Runtime | require("postcss-preset-env") | import "postcss-preset-env" |
|---|---|---|
| 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-preset-env

ES modules:

```js
import * as postcssPresetEnv from "postcss-preset-env";
```

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

CommonJS:

```js
// Node.js 20.19+, 22.12+ and newer (verified):
const postcssPresetEnv = require("postcss-preset-env");

// Any Node.js version the package supports (>=20.19.0), from an async function:
async function main() {
  const postcssPresetEnv = await import("postcss-preset-env");
}

// Or pin the last CommonJS release (declares Node.js >=18):
// npm install postcss-preset-env@10.6.1
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (153 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 11.0.0 – 11.5.2 | ESM-only | Jan 14, 2026 |
| 9.5.1 – 10.6.1 | Dual (CommonJS + ESM) | Mar 13, 2024 |

## Frequently asked

**Is postcss-preset-env ESM-only?**

postcss-preset-env@11.5.2 is ESM-only. postcss-preset-env dropped its CommonJS build in 11.0.0 (January 2026). The last version with a plain require()-able CommonJS entry is 10.6.1, published Jan 10, 2026; it declares support for Node.js >=18.

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

10.6.1 is the last version of postcss-preset-env with a CommonJS build; it declares Node.js >=18. Install it with "npm install postcss-preset-env@10.6.1". Every version from 11.0.0 on is ESM-only.

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

From a CommonJS file, use a dynamic import inside an async function: const postcssPresetEnv = await import("postcss-preset-env"). That works on every Node.js version the package supports (>=20.19.0). On Node.js 20.19+, 22.12+ and newer, require("postcss-preset-env") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26. Alternatively pin postcss-preset-env@10.6.1 (declares Node.js >=18).

**Does postcss-preset-env work in Bun?**

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

**Does postcss-preset-env ship TypeScript types?**

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

## Links

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