JUnit

Free plan Self-hosted

What JUnit is

JUnit is a free testing framework for Java and the JVM, with support for Java, Kotlin, and Groovy. The current JUnit 6.1.3 generation requires Java 17 or newer at runtime, and Kotlin use requires Kotlin 2.1 or above. Its architecture has three parts: JUnit Platform, JUnit Jupiter, and JUnit Vintage. The Platform supplies the TestEngine API, Console Launcher, and Suite Engine for starting JVM testing frameworks. Jupiter combines the programming and extension models used to write tests and extensions. Vintage runs JUnit 3 and JUnit 4 tests for temporary migration, requires JUnit 4.12 or later, and is deprecated. Platform integrations are listed for IntelliJ IDEA, Eclipse, NetBeans, Visual Studio Code, Gradle, Maven, Ant, Bazel, and sbt. JUnit supports parameterized cases and parallel execution. Artifacts are deployed to Maven Central and signed release files are listed. JUnit 6.1.x and 5.14.x are supported lines; versions below 5.14 are unsupported. Community help is available through Stack Overflow and GitHub Discussions.

Who it suits

JUnit suits developers building tests for Java, Kotlin, or Groovy applications on the JVM. Its IDE, build-tool, parameterized-test, and parallel-execution support fit established development pipelines.

What it does well

Supports Java, Kotlin, and Groovy
Integrates with major IDEs and build tools
Provides parameterized cases and parallel execution
JUnit Platform launches JVM test engines
Artifacts are available through Maven Central

What to know first

JUnit 6 requires Java 17 or newer
Kotlin projects require Kotlin 2.1 or above
Vintage engine is deprecated
Versions below 5.14 are unsupported

Plans

Plan	Billed and limits	Price
JUnit	Eclipse Public License v2.0 · released for everyone	Free

As junit.org lists them, read 30 Sept 2026. The maker's own page has the final word.

Verdict

JUnit provides a structured testing stack with broad IDE and build integrations. Check runtime and Kotlin requirements, and treat Vintage as a temporary migration component.

Facts from JUnit's own pages

Architecture: JUnit 6.1.3 consists of JUnit Platform, JUnit Jupiter, and JUnit Vintage. · docs.junit.org, 30 Sept 2026
Build integrations: The JUnit Platform has first-class support in Gradle, Maven, Ant, Bazel, and sbt. · docs.junit.org, 30 Sept 2026
Commercial support: Core JUnit team members offer commercial support through OpenElements, including 4–8 hours of support per month, guaranteed response time, quarterly expert webinars, and a monthly newsletter. · junit.org, 30 Sept 2026
Community support: JUnit directs users to Stack Overflow and GitHub Discussions for questions. · docs.junit.org, 30 Sept 2026
Current generation: JUnit 6.1.3 is the current generation and requires Java 17 or higher at runtime. · junit.org, 30 Sept 2026
Distribution: JUnit artifacts are deployed to Maven Central and the released files are signed with keys listed in the KEYS file. · junit.org, 30 Sept 2026
IDE integrations: The JUnit Platform has first-class support in IntelliJ IDEA, Eclipse, NetBeans, and Visual Studio Code. · docs.junit.org, 30 Sept 2026
Jupiter: JUnit Jupiter combines the programming model and extension model for writing JUnit tests and extensions. · docs.junit.org, 30 Sept 2026
Kotlin requirement: JUnit 6 requires Kotlin 2.1 or above. · junit.org, 30 Sept 2026
Platform: JUnit Platform provides the TestEngine API, Console Launcher, and Suite Engine for launching testing frameworks on the JVM. · docs.junit.org, 30 Sept 2026
Purpose: JUnit is a programmer-friendly testing framework for Java and the JVM. · junit.org, 30 Sept 2026
Security policy: JUnit JARs released on Maven Central are signed; versions 6.1.x and 5.14.x are supported, while versions below 5.14 are unsupported. · github.com, 30 Sept 2026
Vintage engine: JUnit Vintage runs JUnit 3 and JUnit 4 tests, requires JUnit 4.12 or later, and is deprecated for temporary migration use. · docs.junit.org, 30 Sept 2026
Vulnerability reporting: Security vulnerabilities can be reported privately on GitHub or by email to [email protected] using the published OpenPGP key. · github.com, 30 Sept 2026