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

> indent-string@5.0.0 is ESM-only. ESM-only since 5.0.0 — last CommonJS version is 4.0.0.

Indent each line in a string

Last verified Sep 9, 2026 against indent-string@5.0.0.

indent-string dropped its CommonJS build in 5.0.0 (April 2021). The last version with a plain require()-able CommonJS entry is 4.0.0, published Apr 17, 2019; it declares support for Node.js >=8.

On Node.js 20.19+, 22.12+ and newer, require("indent-string") 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("indent-string") fails with ERR_REQUIRE_ESM.

## What to do

1. On Node.js 20.19+, 22.12+ and newer, require("indent-string") 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 indentString = await import("indent-string"). 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 indent-string@4.0.0, the last CommonJS release (published Apr 17, 2019); it declares Node.js >=8.
4. TypeScript: npm install -D @types/indent-string

## Facts

- Latest: 5.0.0 (Apr 17, 2021)
- Module format: ESM-only
- Last CommonJS version: 4.0.0
- ESM-only since: 5.0.0 (Apr 17, 2021)
- TypeScript types: @types/indent-string
- Node engines: >=12
- Weekly downloads: 94.0M
- License: MIT

## Runtime test results for indent-string@5.0.0

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

| Runtime | require("indent-string") | import "indent-string" |
|---|---|---|
| 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 indent-string

ES modules:

```js
import * as indentString from "indent-string";
```

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 indentString = require("indent-string");

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

// Or pin the last CommonJS release (declares Node.js >=8):
// npm install indent-string@4.0.0
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (16 versions; the newest 16 shown).

| Versions | Format | First published |
|---|---|---|
| 5.0.0 | ESM-only | Apr 17, 2021 |
| 0.1.0 – 4.0.0 | CommonJS | Jun 6, 2014 |

## Frequently asked

**Is indent-string ESM-only?**

indent-string@5.0.0 is ESM-only. indent-string dropped its CommonJS build in 5.0.0 (April 2021). The last version with a plain require()-able CommonJS entry is 4.0.0, published Apr 17, 2019; it declares support for Node.js >=8.

**Which version of indent-string still supports CommonJS / require()?**

4.0.0 is the last version of indent-string with a CommonJS build; it declares Node.js >=8. Install it with "npm install indent-string@4.0.0". Every version from 5.0.0 on is ESM-only.

**How do I use indent-string from a CommonJS file?**

From a CommonJS file, use a dynamic import inside an async function: const indentString = await import("indent-string"). That works on every Node.js version the package supports (>=12). On Node.js 20.19+, 22.12+ and newer, require("indent-string") works with the latest version: Node.js loads synchronous ES modules through require(). Verified on Node.js 20, 22, 24 and 26. Alternatively pin indent-string@4.0.0 (declares Node.js >=8).

**Does indent-string work in Bun?**

Yes. import "indent-string" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does indent-string ship TypeScript types?**

Not bundled. Install the community types with "npm install -D @types/indent-string".

## Links

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

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