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Comparison guide
Jest vs Vitest
Side-by-side NPM package comparison
vitest
Next generation testing framework powered by Vite
Downloads unavailable · 89.4 KB gzip · Health 67/100
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Choosing between Jest and Vitest? Here's a data-driven comparison based on real npm data — downloads, bundle size, health scores, and more — to help you decide which package fits your project best.
Downloads & Popularity
Weekly download data is unavailable for Jest. Weekly download data is unavailable for Vitest. Missing data is not zero downloads. We cannot compare download activity until all counts are available.
Bundle Size
Jest has the smallest gzipped bundle at 2.0 KB. Vitest comes in at 89.4 KB. A smaller bundle size means faster page loads, which improves user experience and Core Web Vitals scores.
Health Score Comparison
Jest has an overall health score of 68/100 (good), with strong maintenance, quality, security scores. Vitest has an overall health score of 67/100 (good), with strong maintenance, security scores. Health scores are calculated from maintenance activity, code quality, security posture, popularity, and stability metrics. Download data is incomplete; these composite scores include a fallback popularity input and should not determine an overall winner.
When to Choose Each
Choose Jest if you value minimal bundle footprint, strong security track record. Choose Vitest if you value actively maintained, strong security track record.
Our Verdict
Download data is incomplete for this comparison of Jest and Vitest. We are not selecting an overall winner from incomplete metrics. Compare the available bundle, maintenance, and quality information against your project's requirements.
Frequently Asked Questions
- Is jest better than vitest?
- It depends on your needs. Jest has a health score of 68/100 while Vitest scores 67/100. Weekly download data is incomplete, so no popularity ranking is available. Consider your specific requirements — bundle size, community support, and feature set — to decide which is the better fit.
- Which has a smaller bundle size, jest or vitest?
- Jest has the smaller gzipped bundle at 2.0 KB. A smaller bundle means faster load times for your users, which can positively impact SEO and user experience.
- How many developers use jest vs vitest?
- Weekly download data is incomplete, so no popularity ranking is available. Download counts reflect package installations, not unique developers.
- Which is better maintained, jest or vitest?
- Vitest has a maintenance score of 100/100. Jest scores 80/100 and Vitest scores 100/100 on maintenance.
Jest vs Vitest: The Established Standard vs The Modern Challenger
Jest and Vitest are the two dominant JavaScript testing frameworks in 2026, and migrating from Jest to Vitest has become one of the most common developer tooling upgrades. Jest, maintained by Meta, set the standard for JavaScript testing with snapshot testing, built-in mocking, and zero-config setup. Vitest, built on top of Vite, offers a Jest-compatible API with dramatically faster test execution — often 3-5x faster for large test suites thanks to Vite's native ES module handling and on-demand transformation.
The key differentiator is developer experience during active development. Vitest's watch mode re-runs only affected tests nearly instantly, because it leverages Vite's module graph to know exactly which tests depend on which files. Jest's watch mode is functional but noticeably slower, especially in large monorepos. Vitest also shares your Vite configuration, so if your project already uses Vite, there's zero additional build config for tests — your path aliases, plugins, and transforms just work.
If you're on a Vite-based project (Vue, Svelte, Solid, or React with Vite), Vitest is the clear choice — faster execution, shared config, and seamless integration. If you're on Next.js or a non-Vite build system, Jest remains well-supported and reliable. For new projects in 2026, Vitest is the default recommendation unless you depend specifically on Jest's ecosystem.
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