---
url: /guide.md
---

# Getting Started

## Overview

Vitest (pronounced as *"veetest"*) is a next generation testing framework
powered by
Vite.

You can learn more about the rationale behind the project in the [Why Vitest](/guide/why) section.

## Trying Vitest Online

You can try Vitest online on [StackBlitz](https://vitest.new). It runs Vitest directly in the browser, and it is almost identical to the local setup but doesn't require installing anything on your machine.

## Adding Vitest to Your Project

Learn how to install by Video

::: code-group

```bash [npm]
npm install -D vitest
```

```bash [yarn]
yarn add -D vitest vite
```

```bash [pnpm]
pnpm add -D vitest
```

```bash [bun]
bun add -D vitest
```

```bash [deno]
deno add -D vitest
```

:::

:::tip
Vitest requires Vite >=v6.4.0 and Node >=v22.12.0
:::

It is recommended that you install a copy of `vitest` in your `package.json`, using one of the methods listed above. However, if you would prefer to run `vitest` directly, you can use `npx vitest` (the `npx` tool comes with npm and Node.js).

The `npx` tool will execute the specified command. By default, `npx` will first check if the command exists in the local project's binaries. If it is not found there, `npx` will look in the system's `$PATH` and execute it if found. If the command is not found in either location, `npx` will install it in a temporary location prior to execution.

Vitest and third party integrations can use `.vitest` directory to store generated artifacts. It's recommended to add this in your `.gitignore`.

```sh [.gitignore]
# Vitest reports and artifacts
.vitest/
```

## Writing Tests

As an example, we will write a simple test that verifies the output of a function that adds two numbers.

```js [sum.js]
export function sum(a, b) {
  return a + b
}
```

```js [sum.test.js]
import { expect, test } from 'vitest'
import { sum } from './sum.js'

test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3)
})
```

::: tip
By default, tests must contain `.test.` or `.spec.` in their file name.
:::

Next, in order to execute the test, add the following section to your `package.json`:

```json [package.json]
{
  "scripts": {
    "test": "vitest"
  }
}
```

Finally, run `npm run test`, `yarn test` or `pnpm test`, depending on your package manager, and Vitest will print this message:

```txt
✓ sum.test.js (1)
  ✓ adds 1 + 2 to equal 3

Test Files  1 passed (1)
     Tests  1 passed (1)
  Start at  02:15:44
  Duration  311ms
```

::: warning
If you are using Bun as your package manager, make sure to use `bun run test` command instead of `bun test`, otherwise Bun will run its own test runner.
:::

Your first test is passing! Continue to [Writing Tests](/guide/learn/writing-tests) to learn about organizing tests, reading test output, and the core testing patterns you'll use every day.

To run tests once without watching for file changes, use `vitest run`. You can also pass additional flags like `--reporter` or `--coverage`. For a full list of CLI options, run `npx vitest --help` or see the [CLI guide](/guide/cli).

## Configuring Vitest

Vitest reads your `vite.config.*` by default, so your existing Vite plugins and configuration work out-of-the-box. You can also create a dedicated `vitest.config.*` for test-specific settings. See the [Config Reference](/config/) for details.

## IDE Integrations

We also provided an official extension for Visual Studio Code to enhance your testing experience with Vitest.

[Install from VS Code Marketplace](https://marketplace.visualstudio.com/items?itemName=vitest.explorer)

Learn more about [IDE Integrations](/guide/ide)

## Examples

| Example          | Source                                                                               | Playground                                                                                                                        |
| ---------------- | ------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------- |
| `basic`          | [GitHub](https://github.com/vitest-dev/vitest/tree/main/examples/basic)              | [Play Online](https://stackblitz.com/fork/github/vitest-dev/vitest/tree/main/examples/basic?initialPath=__vitest__/)              |
| `fastify`        | [GitHub](https://github.com/vitest-dev/vitest/tree/main/examples/fastify)            | [Play Online](https://stackblitz.com/fork/github/vitest-dev/vitest/tree/main/examples/fastify?initialPath=__vitest__/)            |
| `in-source-test` | [GitHub](https://github.com/vitest-dev/vitest/tree/main/examples/in-source-test)     | [Play Online](https://stackblitz.com/fork/github/vitest-dev/vitest/tree/main/examples/in-source-test?initialPath=__vitest__/)     |
| `lit`            | [GitHub](https://github.com/vitest-dev/vitest/tree/main/examples/lit)                | [Play Online](https://stackblitz.com/fork/github/vitest-dev/vitest/tree/main/examples/lit?initialPath=__vitest__/)                |
| `vue`            | [GitHub](https://github.com/vitest-tests/browser-examples/tree/main/examples/vue)    | [Play Online](https://stackblitz.com/fork/github/vitest-tests/browser-examples/tree/main/examples/vue?initialPath=__vitest__/)    |
| `marko`          | [GitHub](https://github.com/vitest-tests/browser-examples/tree/main/examples/marko)  | [Play Online](https://stackblitz.com/fork/github/vitest-tests/browser-examples/tree/main/examples/marko?initialPath=__vitest__/)  |
| `preact`         | [GitHub](https://github.com/vitest-tests/browser-examples/tree/main/examples/preact) | [Play Online](https://stackblitz.com/fork/github/vitest-tests/browser-examples/tree/main/examples/preact?initialPath=__vitest__/) |
| `qwik`           | [GitHub](https://github.com/vitest-tests/browser-examples/tree/main/examples/qwik)   | [Play Online](https://stackblitz.com/fork/github/vitest-tests/browser-examples/tree/main/examples/qwik?initialPath=__vitest__/)   |
| `react`          | [GitHub](https://github.com/vitest-tests/browser-examples/tree/main/examples/react)  | [Play Online](https://stackblitz.com/fork/github/vitest-tests/browser-examples/tree/main/examples/react?initialPath=__vitest__/)  |
| `solid`          | [GitHub](https://github.com/vitest-tests/browser-examples/tree/main/examples/solid)  | [Play Online](https://stackblitz.com/fork/github/vitest-tests/browser-examples/tree/main/examples/solid?initialPath=__vitest__/)  |
| `svelte`         | [GitHub](https://github.com/vitest-tests/browser-examples/tree/main/examples/svelte) | [Play Online](https://stackblitz.com/fork/github/vitest-tests/browser-examples/tree/main/examples/svelte?initialPath=__vitest__/) |
| `profiling`      | [GitHub](https://github.com/vitest-dev/vitest/tree/main/examples/profiling)          | Not Available                                                                                                                     |
| `typecheck`      | [GitHub](https://github.com/vitest-dev/vitest/tree/main/examples/typecheck)          | [Play Online](https://stackblitz.com/fork/github/vitest-dev/vitest/tree/main/examples/typecheck?initialPath=__vitest__/)          |
| `projects`       | [GitHub](https://github.com/vitest-dev/vitest/tree/main/examples/projects)           | [Play Online](https://stackblitz.com/fork/github/vitest-dev/vitest/tree/main/examples/projects?initialPath=__vitest__/)           |

## Community

If you have questions or need help, reach out to the community at [Discord](https://chat.vitest.dev) and [GitHub Discussions](https://github.com/vitest-dev/vitest/discussions).