xUnit.net 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

.NET Foundation · since 2007

Category standard

VoidZero / OSS community · since 2021

• Per-test instance isolation eliminates a whole class of shared-state bugs by design.
• Idiomatic modern C# — no attribute soup.
• The default in current .NET project templates.

• 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.

• Fewer built-in assertions than NUnit; most teams add FluentAssertions.
• The isolation model surprises developers migrating from NUnit.
• Parallelism defaults occasionally bite on integration tests.

• 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.

New .NET projects.

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