xUnit.net vs AVA

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

Established

OSS community · since 2015

• 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.

• Process isolation catches hidden coupling between tests that other runners hide.
• Concurrent by default, so suites stay fast without configuration.
• Clean, small API with no magic globals.

• 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.

• No DOM environment; not for front-end work.
• No built-in mocking or snapshots comparable to Jest.
• Smaller community than the mainstream runners.

New .NET projects.

Node libraries where test isolation and speed matter more than ecosystem breadth.