Vitest Has a Free Test Runner That Replaces Jest — 10x Faster, Native TypeScript, Vite-Powered

The Testing Problem Jest: slow startup, needs babel transform for TypeScript, fights with ESM. Mocha: no assertions built in. Testing Library: great but needs Jest underneath. Vitest uses Vite's transform pipeline. Native TypeScript and ESM. 10x faster than Jest. Same API. What Vitest Gives You Jest-Compatible API import { describe , it , expect } from ' vitest ' ; describe ( ' math ' , () => { it ( ' adds numbers ' , () => { expect ( 1 + 1 ). toBe ( 2 ); }); it ( ' handles arrays ' , () => { expect ([ 1 , 2 , 3 ]). toContain ( 2 ); expect ([ 1 , 2 , 3 ]). toHaveLength ( 3 ); }); }); Migrating from Jest? Most tests work without changes. Native TypeScript interface User { name : string ; email : string ; } it ( ' creates a user ' , () => { const user : User = createUser ( ' John ' , ' john@example.com ' ); expect ( user . name ). toBe ( ' John ' ); }); No ts-jest . No @babel/preset-typescript . Just write TypeScript. Watch Mode (Instant) vitest # Watch mode by default Vitest re-runs onl