xUnit.net 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

Category standard

.NET Foundation · since 2007

Widely used

TestNG Team · since 2004

• 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.

• 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.

• 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.

• 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.

New .NET projects.

Java Selenium automation frameworks and large integration suites.