Comparison guide
Jest vs Vitest
Side-by-side NPM package comparison

Quick Verdict
Smallest Bundle
Jest
2.0 KB gzipped
Most Popular
Vitest
123.0M weekly downloads
Best Maintained
Jest
100/100 maintenance score
Highest Quality
Jest
80/100 quality score
Overall Pick
Jest
Best all-around based on popularity, size, maintenance & quality
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vitest
Next generation testing framework powered by Vite
123.0M weekly downloads · 101.3 KB gzip · Health 85/100
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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
Vitest leads with 123.0M weekly downloads — roughly 2.7x more. Jest has 46.3M weekly downloads. Higher download counts generally indicate broader community adoption and a larger ecosystem of tutorials, plugins, and support.
Bundle Size
Jest has the smallest gzipped bundle at 2.0 KB. Vitest comes in at 101.3 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 92/100 (excellent), with strong maintenance, quality, security, popularity scores. Vitest has an overall health score of 85/100 (very good), with strong maintenance, security, popularity scores. Health scores are calculated from maintenance activity, code quality, security posture, popularity, and stability metrics.
When to Choose Each
Choose Jest if you value massive community and ecosystem, minimal bundle footprint, actively maintained, strong security track record. Choose Vitest if you value massive community and ecosystem, actively maintained, strong security track record.
Our Verdict
Both Jest and Vitest are solid choices for JavaScript development. Jest has the edge in overall health score (92/100), while each package brings unique strengths to the table. Evaluate them based on your project's priorities — whether that's community size, bundle efficiency, or maintenance activity — and choose the one that aligns best with your requirements.
Frequently Asked Questions
- Is jest better than vitest?
- It depends on your needs. Jest has a health score of 92/100 while Vitest scores 85/100. Vitest has more recorded weekly downloads (123.0M). 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?
- Vitest has more recorded weekly downloads (123.0M). Download counts reflect package installations, not unique developers.
- Which is better maintained, jest or vitest?
- Jest has a maintenance score of 100/100. Jest scores 100/100 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.
Related Comparisons
The 2026 JavaScript Stack Cheatsheet
One PDF: the best package for every category (ORMs, bundlers, auth, testing, state management). Used by 500+ devs. Free, updated monthly.

