JUnit 5 vs NUnit

Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.

JUnit 5NUnit

Entry price

Free and open source

Open source

Free and open source

Open source

What drives the bill

The metric that actually scales your invoice.

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

Free tier

Everything, self-hosted

Open source

EPL-2.0

MIT

Self-hostable

No-code authoring

Languages

JavaKotlin

Platforms

WebAPI

WebAPIDesktop

Fits teams

Solo / side projectStartupScale-up / mid-marketEnterprise

Scale-up / mid-marketEnterprise

Adoption

Category standard

JUnit Team · since 2017

Widely used

.NET Foundation · since 2002

Strengths

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.

Limitations

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.

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.

Best for

Every Java and Kotlin project on the JVM.

Existing .NET codebases already standardised on NUnit.

All of these integrate with: Jenkins.

Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.