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

> tsd@0.33.0 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Check TypeScript type definitions

Last verified Sep 9, 2026 against tsd@0.33.0.

tsd ships CommonJS only. require("tsd") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=14.16. import "tsd" 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("tsd") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=14.16.
2. From ES modules use the default import: import tsd from "tsd"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 0.33.0 (Aug 5, 2025)
- Module format: CommonJS
- Last CommonJS version: 0.33.0
- TypeScript types: bundled
- Node engines: >=14.16
- Weekly downloads: 474K
- License: MIT

## Runtime test results for tsd@0.33.0

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

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

ES modules:

```js
import tsd from "tsd";
```

CommonJS:

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

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (65 versions; the newest 60 shown).

| Versions | Format | First published |
|---|---|---|
| 0.2.2 – 0.33.0 | CommonJS | Nov 8, 2012 |

## Frequently asked

**Is tsd ESM-only?**

tsd@0.33.0 is a CommonJS package. tsd ships CommonJS only. require("tsd") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >=14.16. import "tsd" 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 tsd with ES module syntax?**

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

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

**Does tsd ship TypeScript types?**

Yes. tsd bundles its own type declarations; no @types package is needed.

## Links

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

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