| Aspect | Jest | Vitest |
|---|---|---|
| Foundation | Own runner, transforms via Babel or ts-jest | Vite and esbuild, reuses the project config |
| Speed | Fine, slower on large codebases | Usually faster, especially in watch mode |
| ESM and TypeScript | ESM is experimental, TS needs setup | ESM and TS work out of the box |
| API compatibility | The reference: describe, it, expect, jest.fn | Mostly compatible, vi.fn instead of jest.fn |
| Maintainer | OpenJS Foundation (previously Meta) | Vite team and community |
| License | MIT | MIT |
| Ecosystem | Largest: React Native, Create React App, huge base of examples | Growing fast, the default for Vite projects |
| Best for | React Native, legacy projects, Node services | Vite, Vue, Svelte, new TypeScript projects |
Choose Jest when
- The project is React Native or already has thousands of Jest tests.
- You want the most Stack Overflow answers.
- There is no Vite in your stack.
Choose Vitest when
- The project uses Vite or is a new TypeScript codebase.
- You want fast watch and less configuration.
- You want ESM without hassle.
Bottom line
Use Vitest for a new Vite project. There is no point rewriting an existing Jest setup unless it slows you down.
Compared
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