# Is @jridgewell/gen-mapping ESM-only? Can you require() it?

> @jridgewell/gen-mapping@0.3.13 ships CommonJS and ESM builds. Dual package — require() works on every Node.js version we test; import works too.

Generate source maps

Last verified Sep 9, 2026 against @jridgewell/gen-mapping@0.3.13.

@jridgewell/gen-mapping publishes both a CommonJS entry and a native ESM entry (ESM added in 0.1.0). require("@jridgewell/gen-mapping") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "@jridgewell/gen-mapping" works alongside it.

## What to do

1. Nothing to change. require("@jridgewell/gen-mapping") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import * as genMapping from "@jridgewell/gen-mapping" works alongside it; use named imports for what the ESM entry exports.
2. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 0.3.13 (Aug 12, 2025)
- Module format: Dual (CommonJS + ESM)
- Last CommonJS version: 0.3.13
- Native ESM since: 0.1.0
- TypeScript types: bundled
- Node engines: not declared
- Weekly downloads: 163.4M
- License: MIT

## Runtime test results for @jridgewell/gen-mapping@0.3.13

Installed and executed on Sep 9, 2026 with require("@jridgewell/gen-mapping") from a CommonJS file and import "@jridgewell/gen-mapping" from an ES module.

| Runtime | require("@jridgewell/gen-mapping") | import "@jridgewell/gen-mapping" |
|---|---|---|
| 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 @jridgewell/gen-mapping

ES modules:

```js
import * as genMapping from "@jridgewell/gen-mapping";
```

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

CommonJS:

```js
const genMapping = require("@jridgewell/gen-mapping");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (17 versions; the newest 17 shown).

| Versions | Format | First published |
|---|---|---|
| 0.1.0 – 0.3.13 | Dual (CommonJS + ESM) | Apr 27, 2022 |

## Frequently asked

**Is @jridgewell/gen-mapping ESM-only?**

@jridgewell/gen-mapping@0.3.13 ships CommonJS and ESM builds. @jridgewell/gen-mapping publishes both a CommonJS entry and a native ESM entry (ESM added in 0.1.0). require("@jridgewell/gen-mapping") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "@jridgewell/gen-mapping" works alongside it.

**Can I require @jridgewell/gen-mapping?**

Yes. @jridgewell/gen-mapping ships a CommonJS entry alongside the native ESM entry. require("@jridgewell/gen-mapping") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun.

**Does @jridgewell/gen-mapping work in Bun?**

Yes. import "@jridgewell/gen-mapping" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does @jridgewell/gen-mapping ship TypeScript types?**

Yes. @jridgewell/gen-mapping bundles its own type declarations; no @types package is needed.

## Links

- [@jridgewell/gen-mapping on npm](https://www.npmjs.com/package/@jridgewell/gen-mapping)
- [Source repository](https://github.com/jridgewell/sourcemaps)
- [HTML version](https://canirequire.com/package/@jridgewell/gen-mapping/)
- [JSON version](https://canirequire.com/package/@jridgewell/gen-mapping.json)

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