Mocha vs NUnit

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

Widely used

OpenJS Foundation · since 2011

Widely used

.NET Foundation · since 2002

• Small, stable and predictable — it does one job and has done it the same way for years.
• Pick your own assertions, mocks and coverage rather than accepting a bundle.
• Excellent async and reporter support.

• The most expressive built-in assertion library in .NET.
• Familiar attribute model for teams migrating from older frameworks.
• Very stable, very long-lived.

• No built-in mocking, snapshots, coverage or parallel-by-default execution.
• Assembling and documenting the stack is work every new project repeats.
• Fewer new projects adopt it; momentum sits with Vitest and Jest.

• Shared test-class instances mean state can leak between tests unless you are careful.
• New Microsoft templates default to xUnit, so it is drifting from the mainstream.
• Attribute-heavy style feels dated.

Node.js services where you want explicit control over every part of the test stack.

Existing .NET codebases already standardised on NUnit.