# Is @isaacs/cliui ESM-only? Can you require() it?

> @isaacs/cliui@9.0.0 ships CommonJS and ESM builds. Dual package — require() works on every Node.js version we test; import works too.

easily create complex multi-column command-line-interfaces

Last verified Sep 9, 2026 against @isaacs/cliui@9.0.0.

@isaacs/cliui publishes both a CommonJS entry and a native ESM entry (ESM added in 8.0.2). require("@isaacs/cliui") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=18. import "@isaacs/cliui" works alongside it.

## What to do

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

## Facts

- Latest: 9.0.0 (Feb 5, 2026)
- Module format: Dual (CommonJS + ESM)
- Last CommonJS version: 9.0.0
- Native ESM since: 8.0.2
- TypeScript types: bundled
- Node engines: >=18
- Weekly downloads: 72.9M
- License: BlueOak-1.0.0

## Runtime test results for @isaacs/cliui@9.0.0

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

| Runtime | require("@isaacs/cliui") | import "@isaacs/cliui" |
|---|---|---|
| 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 @isaacs/cliui

ES modules:

```js
import * as cliui from "@isaacs/cliui";
```

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

CommonJS:

```js
const cliui = require("@isaacs/cliui");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (2 versions; the newest 2 shown).

| Versions | Format | First published |
|---|---|---|
| 8.0.2 – 9.0.0 | Dual (CommonJS + ESM) | May 2, 2023 |

## Frequently asked

**Is @isaacs/cliui ESM-only?**

@isaacs/cliui@9.0.0 ships CommonJS and ESM builds. @isaacs/cliui publishes both a CommonJS entry and a native ESM entry (ESM added in 8.0.2). require("@isaacs/cliui") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=18. import "@isaacs/cliui" works alongside it.

**Can I require @isaacs/cliui?**

Yes. @isaacs/cliui ships a CommonJS entry alongside the native ESM entry. require("@isaacs/cliui") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=18.

**Does @isaacs/cliui work in Bun?**

Yes. import "@isaacs/cliui" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does @isaacs/cliui ship TypeScript types?**

Yes. @isaacs/cliui bundles its own type declarations; no @types package is needed.

## Links

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

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