# Is is-path-inside ESM-only? Can you require() it?

> is-path-inside@4.0.0 is ESM-only. ESM-only since 4.0.0 — last CommonJS version is 3.0.3.

Check if a path is inside another path

Last verified Sep 9, 2026 against is-path-inside@4.0.0.

is-path-inside dropped its CommonJS build in 4.0.0 (May 2021). The last version with a plain require()-able CommonJS entry is 3.0.3, published Mar 8, 2021; it declares support for Node.js >=8.

On Node.js 20.19+, 22.12+ and newer, require("is-path-inside") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26. On Node.js 18, which has no require(esm), require("is-path-inside") fails with ERR_REQUIRE_ESM.

## What to do

1. On Node.js 20.19+, 22.12+ and newer, require("is-path-inside") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26.
2. From a CommonJS file, use a dynamic import inside an async function: const isPathInside = await import("is-path-inside"). That works on every Node.js version the package supports (>=12).
3. If you need a synchronous require() or run Node.js 18: npm install is-path-inside@3.0.3, the last CommonJS release (published Mar 8, 2021); it declares Node.js >=8.
4. TypeScript: no types are available for is-path-inside; declare the module yourself if you need them.

## Facts

- Latest: 4.0.0 (May 3, 2021)
- Module format: ESM-only
- Last CommonJS version: 3.0.3
- ESM-only since: 4.0.0 (May 3, 2021)
- TypeScript types: none
- Node engines: >=12
- Weekly downloads: 48.4M
- License: MIT

## Runtime test results for is-path-inside@4.0.0

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

| Runtime | require("is-path-inside") | import "is-path-inside" |
|---|---|---|
| Node.js 18 | fails (ERR_REQUIRE_ESM) | 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 is-path-inside

ES modules:

```js
import * as isPathInside from "is-path-inside";
```

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

CommonJS:

```js
// Node.js 20.19+, 22.12+ and newer (verified):
const isPathInside = require("is-path-inside");

// Any Node.js version the package supports (>=12), from an async function:
async function main() {
  const isPathInside = await import("is-path-inside");
}

// Or pin the last CommonJS release (declares Node.js >=8):
// npm install is-path-inside@3.0.3
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (10 versions; the newest 10 shown).

| Versions | Format | First published |
|---|---|---|
| 4.0.0 | ESM-only | May 3, 2021 |
| 0.1.0 – 3.0.3 | CommonJS | Jun 20, 2014 |

## Frequently asked

**Is is-path-inside ESM-only?**

is-path-inside@4.0.0 is ESM-only. is-path-inside dropped its CommonJS build in 4.0.0 (May 2021). The last version with a plain require()-able CommonJS entry is 3.0.3, published Mar 8, 2021; it declares support for Node.js >=8.

**Which version of is-path-inside still supports CommonJS / require()?**

3.0.3 is the last version of is-path-inside with a CommonJS build; it declares Node.js >=8. Install it with "npm install is-path-inside@3.0.3". Every version from 4.0.0 on is ESM-only.

**How do I use is-path-inside from a CommonJS file?**

From a CommonJS file, use a dynamic import inside an async function: const isPathInside = await import("is-path-inside"). That works on every Node.js version the package supports (>=12). On Node.js 20.19+, 22.12+ and newer, require("is-path-inside") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26. Alternatively pin is-path-inside@3.0.3 (declares Node.js >=8).

**Does is-path-inside work in Bun?**

Yes. import "is-path-inside" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does is-path-inside ship TypeScript types?**

No. is-path-inside ships no type declarations and there is no @types package for it.

## Links

- [is-path-inside on npm](https://www.npmjs.com/package/is-path-inside)
- [Source repository](https://github.com/sindresorhus/is-path-inside)
- [HTML version](https://canirequire.com/package/is-path-inside/)
- [JSON version](https://canirequire.com/package/is-path-inside.json)

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