NUnit vs TestNG

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

.NET Foundation · since 2002

Widely used

TestNG Team · since 2004

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

• Mature parallel-execution and grouping model, ideal for large Selenium suites.
• Data providers make data-driven testing straightforward.
• Test dependencies and ordering, which JUnit deliberately avoids.

• 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.

• XML suite configuration is dated and error-prone.
• Test dependencies encourage ordering coupling that makes suites fragile.
• Community momentum favours JUnit 5 for new projects.

Existing .NET codebases already standardised on NUnit.

Java Selenium automation frameworks and large integration suites.