# Is eventemitter3 ESM-only? Can you require() it?

> eventemitter3@5.0.4 ships CommonJS and ESM builds. Dual package — require() works on every Node.js version we test; import works too.

EventEmitter3 focuses on performance while maintaining a Node.js AND browser compatible interface.

Last verified Sep 9, 2026 against eventemitter3@5.0.4.

eventemitter3 publishes both a CommonJS entry and a native ESM entry (ESM added in 5.0.0). require("eventemitter3") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "eventemitter3" works alongside it.

## What to do

1. Nothing to change. require("eventemitter3") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import * as eventemitter3 from "eventemitter3" works alongside it; use named imports for what the ESM entry exports.
2. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 5.0.4 (Jan 19, 2026)
- Module format: Dual (CommonJS + ESM)
- Last CommonJS version: 5.0.4
- Native ESM since: 5.0.0
- TypeScript types: bundled
- Node engines: not declared
- Weekly downloads: 136.6M
- License: MIT

## Runtime test results for eventemitter3@5.0.4

Installed and executed on Sep 9, 2026 with require("eventemitter3") from a CommonJS file and import "eventemitter3" from an ES module.

| Runtime | require("eventemitter3") | import "eventemitter3" |
|---|---|---|
| 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 eventemitter3

ES modules:

```js
import * as eventemitter3 from "eventemitter3";
```

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

CommonJS:

```js
const eventemitter3 = require("eventemitter3");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (38 versions; the newest 38 shown).

| Versions | Format | First published |
|---|---|---|
| 5.0.0 – 5.0.4 | Dual (CommonJS + ESM) | Nov 28, 2022 |
| 0.0.0 – 4.0.7 | CommonJS | Sep 25, 2013 |

## Frequently asked

**Is eventemitter3 ESM-only?**

eventemitter3@5.0.4 ships CommonJS and ESM builds. eventemitter3 publishes both a CommonJS entry and a native ESM entry (ESM added in 5.0.0). require("eventemitter3") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. import "eventemitter3" works alongside it.

**Can I require eventemitter3?**

Yes. eventemitter3 ships a CommonJS entry alongside the native ESM entry. require("eventemitter3") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun.

**Does eventemitter3 work in Bun?**

Yes. import "eventemitter3" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does eventemitter3 ship TypeScript types?**

Yes. eventemitter3 bundles its own type declarations; no @types package is needed.

## Links

- [eventemitter3 on npm](https://www.npmjs.com/package/eventemitter3)
- [Source repository](https://github.com/primus/eventemitter3)
- [HTML version](https://canirequire.com/package/eventemitter3/)
- [JSON version](https://canirequire.com/package/eventemitter3.json)

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