Migrate to JUnit 5
JUnit 5 (also known as JUnit Jupiter) was released in 2017 and introduced significant improvements over JUnit 4.
Migrate to JUnit 6
JUnit 6 was released in 2025. The main change is a baseline requirement of Java 17, which affects tests using conditional execution annotations like @EnabledOnJre and @DisabledOnJre.
JUnit Jupiter best practices
After migrating to JUnit 5, there are several common patterns that should be cleaned up to make tests more modern and maintainable.
Parameterized tests
Instead of writing multiple similar test methods that differ only in input values and expected results, use @ParameterizedTest to run the same test logic with different parameters. This reduces code duplication and makes it easier to add more test cases.
Nested tests
JUnit Jupiter supports nested test classes to better organize related tests and share setup code.
Practice: Migrate to JUnit 5
Ready to practice migrating from JUnit 4 to JUnit 5? We've prepared a test class with common JUnit 4 patterns that you can improve.
Practice: Parameterized Class
Ready to practice using JUnit 6's @ParameterizedClass to parameterize entire test classes? We've prepared a test class