xUnit.net vs TestNG
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.
Entry price
Free and open source
Open sourceFree and open source
Open sourceWhat drives the bill
The metric that actually scales your invoice.
Free and open source. You pay in engineering time and CI minutes.
Free and open source. You pay in engineering time and CI minutes.
Free tier
Everything, self-hosted
Everything, self-hosted
Open source
Apache-2.0
Apache-2.0
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Category standard
.NET Foundation · since 2007
Widely used
TestNG Team · since 2004
Strengths
- 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.
Limitations
- 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.
Best for
New .NET projects.
Java Selenium automation frameworks and large integration suites.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.