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

> optionator@0.9.4 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

option parsing and help generation

Last verified Sep 9, 2026 against optionator@0.9.4.

optionator ships CommonJS only. require("optionator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.8.0. import "optionator" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

## What to do

1. require("optionator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.8.0.
2. From ES modules use the default import: import optionator from "optionator"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: no types are available for optionator; declare the module yourself if you need them.

## Facts

- Latest: 0.9.4 (Apr 26, 2024)
- Module format: CommonJS
- Last CommonJS version: 0.9.4
- TypeScript types: none
- Node engines: >= 0.8.0
- Weekly downloads: 102.4M
- License: MIT

## Runtime test results for optionator@0.9.4

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

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

ES modules:

```js
import optionator from "optionator";
```

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (20 versions; the newest 20 shown).

| Versions | Format | First published |
|---|---|---|
| 0.1.0 – 0.9.4 | CommonJS | Nov 2, 2013 |

## Frequently asked

**Is optionator ESM-only?**

optionator@0.9.4 is a CommonJS package. optionator ships CommonJS only. require("optionator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.8.0. import "optionator" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

**Can I import optionator with ES module syntax?**

Yes. import optionator from "optionator" works in Node.js and Bun because they support importing CommonJS modules. Named imports work only when Node.js can statically detect the exports.

**Does optionator work in Bun?**

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

**Does optionator ship TypeScript types?**

No. optionator ships no type declarations and there is no @types package for it.

## Links

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

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