JUnit 5 vs Vitest

Free and open source

Free and open source

Free and open source. You pay in engineering time and CI minutes.

Free and open source. You pay in engineering time and CI minutes.

Everything, self-hosted

Everything, self-hosted

Category standard

JUnit Team · since 2017

Category standard

VoidZero / OSS community · since 2021

• Universal support across IDEs, build tools and CI in the Java ecosystem.
• The extension model replaced JUnit 4's runners and rules with something composable.
• Pairs cleanly with Mockito, AssertJ, Spring Test and Testcontainers.

• Fastest watch-mode feedback of the JavaScript runners, by a wide margin on large repos.
• Zero-config ESM and TypeScript — the single biggest source of Jest configuration pain simply disappears.
• Jest-compatible API means migration is usually a day, not a quarter.

• Java verbosity persists — expect more lines per test than in Python or JavaScript.
• Parallel execution is opt-in and still occasionally surprising.
• Mixed JUnit 4 and 5 codebases need the vintage engine and stay confusing for years.

• Assumes Vite. On a Webpack or Metro project the advantage largely evaporates.
• Younger ecosystem; a handful of niche Jest plugins have no equivalent.
• Browser mode is still maturing relative to a dedicated component test runner.

Every Java and Kotlin project on the JVM.

Any Vite-based project, and most new JavaScript projects generally.