unittest 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

Python Software Foundation · since 2001

Widely used

TestNG Team · since 2004

• In the standard library — nothing to install or vet.
• unittest.mock is excellent and used almost universally in Python.
• Familiar to anyone coming from JUnit or NUnit.

• 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.

• Verbose compared to pytest for the same coverage.
• No parametrisation or fixture composition worth the name.
• Most teams run unittest tests through pytest anyway.

• 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.

Standard-library-only environments and codebases that already use it.

Java Selenium automation frameworks and large integration suites.