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

> nyc@18.0.0 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

the Istanbul command line interface

Last verified Sep 9, 2026 against nyc@18.0.0.

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

## Facts

- Latest: 18.0.0 (Feb 22, 2026)
- Module format: CommonJS
- Last CommonJS version: 18.0.0
- TypeScript types: none
- Node engines: 20 || >=22
- Weekly downloads: 7.5M
- License: ISC

## Runtime test results for nyc@18.0.0

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

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

ES modules:

```js
import nyc from "nyc";
```

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (115 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 6.4.2 – 18.0.0 | CommonJS | May 2, 2016 |

## Frequently asked

**Is nyc ESM-only?**

nyc@18.0.0 is a CommonJS package. nyc ships CommonJS only. require("nyc") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js 20 || >=22. import "nyc" 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 nyc with ES module syntax?**

Yes. import nyc from "nyc" 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 nyc work in Bun?**

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

**Does nyc ship TypeScript types?**

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

## Links

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

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