uvu vs Vitest

uvu is a free, lightweight test runner for Node.js and browser projects. It supports individually executable test files, asynchronous tests that may return Promises, native ES modules and a familiar API. Tests can be grouped into named suites or registered through a simpler test interface, and snapshot testing is supported. Each file is self-contained and can also be run directly with Node.js. The optional CLI collects and executes suites, with options to stop after the first failure, ignore patterns, preload modules, set a working directory and colorize output. When a directory is specified, file matching takes a regular-expression pattern rather than relying on glob patterns. The optional assertion module works in browsers and can be swapped for another library, including Node.js’s native assert. Installation uses `npm install --save-dev uvu`. Package metadata specifies Node.js version `>=8`; the repository identifies the project as MIT licensed and credits Luke Edwards.

Vitest is a free and open-source testing framework powered by Vite, though it can also run without Vite. It can reuse Vite configuration, plugins, resolvers, and transform pipelines. Jest-compatible APIs cover assertions, snapshots, and mocking, which can support migration from Jest. Watch mode reruns tests related to changed source or test files, and TypeScript, JSX, and ES modules work out of the box. Browser Mode runs tests in a browser and supports Playwright and WebdriverIO providers. Component testing covers Vue, React, Svelte, Lit, Marko, and other frameworks. Vitest supports coverage through V8 or Istanbul, benchmarking powered by Tinybench, parallel execution, parameterized cases, and property-based checks. An official Visual Studio Code extension is available, and the framework can be tried in StackBlitz without local installation. The listed requirements are Vite 6.4.0 or later and Node 22.12.0 or later. Help is available through the Vitest Discord community and GitHub Discussions.