---
title: environment | Config
---

# environment

- **Type:** `'node' | 'jsdom' | 'happy-dom' | 'edge-runtime' | string`
- **Default:** `'node'`
- **CLI:** `--environment=<env>`

The environment that will be used for testing. The default environment in Vitest
is a Node.js environment. If you are building a web application, you can use
browser-like environment through either [`jsdom`](https://github.com/jsdom/jsdom)
or [`happy-dom`](https://github.com/capricorn86/happy-dom) instead.
If you are building edge functions, you can use [`edge-runtime`](https://edge-runtime.vercel.app/packages/vm) environment

::: tip
You can also use [Browser Mode](/guide/browser/) to run integration or unit tests in the browser without mocking the environment.
:::

To define custom options for your environment, use [`environmentOptions`](/config/environmentoptions).

By adding a `@vitest-environment` docblock or comment at the top of the file,
you can specify another environment to be used for all tests in that file:

Docblock style:

```js
/**
 * @vitest-environment jsdom
 */

test('use jsdom in this test file', () => {
  const element = document.createElement('div')
  expect(element).not.toBeNull()
})
```

Comment style:

```js
// @vitest-environment happy-dom

test('use happy-dom in this test file', () => {
  const element = document.createElement('div')
  expect(element).not.toBeNull()
})
```

For compatibility with Jest, there is also a `@jest-environment`:

```js
/**
 * @jest-environment jsdom
 */

test('use jsdom in this test file', () => {
  const element = document.createElement('div')
  expect(element).not.toBeNull()
})
```

You can also define a custom environment. When non-builtin environment is used, Vitest will try to load the file if it's relative or absolute, or a package `vitest-environment-${name}`, if the name is a bare specifier.

The custom environment file should export an object with the shape of `Environment`:

```ts [environment.js]
import type { Environment } from 'vitest'

export default <Environment>{
  name: 'custom',
  viteEnvironment: 'ssr',
  setup() {
    // custom setup
    return {
      teardown() {
        // called after all tests with this env have been run
      }
    }
  }
}
```

::: tip
The `viteEnvironment` field corresponds to the environment defined by the [Vite Environment API](https://vite.dev/guide/api-environment#environment-api). By default, Vite exposes `client` (for the browser) and `ssr` (for the server) environments.
:::

Vitest also exposes `builtinEnvironments` through `vitest/environments` entry, in case you just want to extend it. You can read more about extending environments in [our guide](/guide/environment).

::: tip
jsdom environment exposes `jsdom` global variable equal to the current [JSDOM](https://github.com/jsdom/jsdom) instance. If you want TypeScript to recognize it, you can add `vitest/jsdom` to your `tsconfig.json` when you use this environment:

```json [tsconfig.json]
{
  "compilerOptions": {
    "types": ["vitest/jsdom"]
  }
}
```
:::
