# Is @jridgewell/sourcemap-codec ESM-only? Can you require() it?

> @jridgewell/sourcemap-codec@1.6.0 ships CommonJS and ESM builds. Dual package — require() works on every Node.js version we test; import works too.

Encode/decode sourcemap mappings

Last verified Sep 9, 2026 against @jridgewell/sourcemap-codec@1.6.0.

@jridgewell/sourcemap-codec publishes both a CommonJS entry and a native ESM entry (ESM added in 1.4.9). require("@jridgewell/sourcemap-codec") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "@jridgewell/sourcemap-codec" works alongside it.

## What to do

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

## Facts

- Latest: 1.6.0 (Aug 28, 2026)
- Module format: Dual (CommonJS + ESM)
- Last CommonJS version: 1.6.0
- Native ESM since: 1.4.9
- TypeScript types: bundled
- Node engines: not declared
- Weekly downloads: 191.3M
- License: MIT

## Runtime test results for @jridgewell/sourcemap-codec@1.6.0

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

| Runtime | require("@jridgewell/sourcemap-codec") | import "@jridgewell/sourcemap-codec" |
|---|---|---|
| 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/sourcemap-codec

ES modules:

```js
import * as sourcemapCodec from "@jridgewell/sourcemap-codec";
```

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

CommonJS:

```js
const sourcemapCodec = require("@jridgewell/sourcemap-codec");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (14 versions; the newest 14 shown).

| Versions | Format | First published |
|---|---|---|
| 1.4.9 – 1.6.0 | Dual (CommonJS + ESM) | Feb 5, 2022 |

## Frequently asked

**Is @jridgewell/sourcemap-codec ESM-only?**

@jridgewell/sourcemap-codec@1.6.0 ships CommonJS and ESM builds. @jridgewell/sourcemap-codec publishes both a CommonJS entry and a native ESM entry (ESM added in 1.4.9). require("@jridgewell/sourcemap-codec") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "@jridgewell/sourcemap-codec" works alongside it.

**Can I require @jridgewell/sourcemap-codec?**

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

**Does @jridgewell/sourcemap-codec work in Bun?**

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

**Does @jridgewell/sourcemap-codec ship TypeScript types?**

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

## Links

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

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