JUnit vs TestNG: a practical comparison for Java teams

JUnit and TestNG are the two dominant testing frameworks in Java. Both let you write automated tests with annotations, assertions, and lifecycle hooks, but they differ in philosophy, feature depth, and where they excel. This guide gives you the key differences, current version details, and practical guidance on when to use each.

Quick-reference comparison table

Feature	JUnit (5 / 6)	TestNG (7.x)
Latest stable version	JUnit 6.0.2 (Jan 2026); JUnit 5.12.2 for Java 8-16 projects	TestNG 7.11.0
Minimum Java version	Java 17 (JUnit 6); Java 8 (JUnit 5)	Java 11
Test grouping	`@Tag` annotation + suite support	`groups` attribute in `@Test` + XML suite files
Parameterized tests	`@ParameterizedTest` with 7+ argument sources	`@DataProvider` annotation
Test execution order	`@TestMethodOrder` with built-in orderers	`priority` attribute + `dependsOnMethods`
Test dependencies	Not built-in (by design)	`dependsOnMethods` / `dependsOnGroups`
Parallel execution	Configurable via `junit-platform.properties`	Built-in via XML suite configuration
Reporting	XML/HTML via build tools (Maven Surefire, Gradle)	Built-in detailed HTML reports with retry tracking
Configuration	Annotation-driven + properties files	XML suite files + annotations
Kotlin support	Native `suspend` function support (JUnit 6)	Basic Kotlin compatibility
Ecosystem adoption	~62% of Java projects	~6% of Java projects
Diffblue Cover support	JUnit 4.11-4.13, JUnit 5.0-5.12.2, JUnit 6	TestNG 6.0.1-7.10.2

Annotation mapping: JUnit 4 vs JUnit 5/6 vs TestNG

If you’re migrating between frameworks or maintaining a project that uses multiple, this table maps equivalent annotations across all three.

Purpose	JUnit 4	JUnit 5 / 6	TestNG
Mark a test method	`@Test`	`@Test`	`@Test`
Run before each test	`@Before`	`@BeforeEach`	`@BeforeMethod`
Run after each test	`@After`	`@AfterEach`	`@AfterMethod`
Run once before all tests in class	`@BeforeClass`	`@BeforeAll`	`@BeforeClass`
Run once after all tests in class	`@AfterClass`	`@AfterAll`	`@AfterClass`
Disable a test	`@Ignore`	`@Disabled`	`@Test(enabled = false)`
Expected exception	`@Test(expected = ...)`	`assertThrows()`	`@Test(expectedExceptions = ...)`
Timeout	`@Test(timeout = ...)`	`@Timeout`	`@Test(timeOut = ...)`
Parameterized data	`@RunWith(Parameterized.class)`	`@ParameterizedTest`	`@DataProvider`
Test grouping / tagging	`@Category`	`@Tag`	`@Test(groups = {...})`
Test ordering	`@FixMethodOrder`	`@TestMethodOrder`	`@Test(priority = ...)`
Test dependencies	—	—	`@Test(dependsOnMethods = ...)`
Run before suite	—	—	`@BeforeSuite`
Run after suite	—	—	`@AfterSuite`
Display name	—	`@DisplayName`	`@Test(description = ...)`
Nested test classes	—	`@Nested`	—
Extensions / Listeners	`@RunWith` / `@Rule`	`@ExtendWith`	`@Listeners`

Note: The @Test annotation comes from different packages in each framework: org.junit.Test (JUnit 4), org.junit.jupiter.api.Test (JUnit 5/6), and org.testng.annotations.Test (TestNG). Watch your imports when migrating.

What changed recently: JUnit 6 and TestNG 7.11

The Java testing landscape shifted in late 2025. JUnit 6.0.0 shipped in September 2025, the first major version bump since JUnit 5 launched in 2017. Meanwhile, TestNG continues steady incremental updates at 7.11.0.

JUnit 6: key changes

Java 17 baseline: JUnit 6 requires Java 17 or higher. Projects on Java 8-16 should stay on JUnit 5.
Unified versioning: Platform, Jupiter, and Vintage now share a single version number, eliminating the confusing split numbering from JUnit 5.
Native Kotlin support: Test and lifecycle methods can now be suspend functions without runBlocking wrappers.
CancellationToken API: Enables cancelling test runs mid-execution. The ConsoleLauncher gained a --fail-fast flag.
JSpecify nullability annotations: Adopted across all modules for better null-safety.

TestNG 7.11: incremental improvements

Bug fixes for ITestResult.status, parallel execution, and DataProvider skip handling.
Added missing assertEquals(long, Long, String) overload.
Updated SLF4J to 2.0.16.
No major architectural changes or new version track planned.

Test organization and grouping

Both frameworks let you organize tests beyond simple class-and-method structure, but they approach it differently.

JUnit: tags and suites

JUnit 5/6 uses the @Tag annotation to label tests, then filters them at execution time through build tool configuration or the @Suite API.

JUnit: tagging tests for selective execution

@Tag("smoke")
@Test
void loginShouldSucceedWithValidCredentials() {
    // test implementation
}

@Tag("regression")
@Test
void loginShouldFailWithExpiredToken() {
    // test implementation
}

TestNG: groups and XML suites

TestNG embeds grouping directly in the @Test annotation and configures execution through XML suite files. This gives you centralized control over which groups run, in what order, and with what parallelism.

TestNG: group-based test organization

@Test(groups = {"smoke", "auth"})
public void loginShouldSucceedWithValidCredentials() {
    // test implementation
}

@Test(groups = {"regression", "auth"})
public void loginShouldFailWithExpiredToken() {
    // test implementation
}

TestNG XML suite: running only smoke tests

<suite name="Smoke Suite" parallel="methods" thread-count="4">
    <test name="Smoke Tests">
        <groups>
            <run>
                <include name="smoke" />
            </run>
        </groups>
        <classes>
            <class name="com.example.AuthTests" />
        </classes>
    </test>
</suite>

Bottom line: TestNG’s grouping is more powerful out of the box, especially for large suites where you need centralized orchestration. JUnit’s tags work well for simpler filtering scenarios driven by your build tool.

Parameterized and data-driven testing

Both frameworks support running the same test logic against multiple data sets. The approaches differ in flexibility and syntax.

JUnit: multiple argument sources

JUnit 5/6 provides @ParameterizedTest with a rich set of built-in argument sources:

@ValueSource – inline primitives and strings
@CsvSource / @CsvFileSource – CSV data inline or from files
@MethodSource – data from a factory method
@EnumSource – enum constants
@ArgumentsProvider – custom implementations

JUnit: parameterized test with multiple sources

@ParameterizedTest
@CsvSource({
    "admin,    true",
    "editor,   true",
    "viewer,   false",
    "guest,    false"
})
void shouldValidateWritePermission(String role, boolean expected) {
    assertEquals(expected, new PermissionService().canWrite(role));
}

TestNG: DataProvider annotation

TestNG uses @DataProvider methods that return Object[][] or Iterator<Object[]>. Data providers can be defined in a separate class and referenced by name, making them reusable across test classes.

TestNG: data-driven test with DataProvider

@DataProvider(name = "rolePermissions")
public Object[][] roleData() {
    return new Object[][] {
        {"admin",  true},
        {"editor", true},
        {"viewer", false},
        {"guest",  false}
    };
}

@Test(dataProvider = "rolePermissions")
public void shouldValidateWritePermission(String role, boolean expected) {
    assertEquals(expected, new PermissionService().canWrite(role));
}

Bottom line: JUnit’s argument source variety covers most parameterization needs cleanly. TestNG’s @DataProvider is more flexible for complex or externally-sourced data, especially when you need to share data sets across multiple test classes.

Test execution order and dependencies

This is where the two frameworks diverge most sharply in philosophy.

JUnit: ordered but independent

JUnit 5/6 supports explicit test ordering via @TestMethodOrder with four built-in orderers:

Orderer	Behavior
`OrderAnnotation`	Sort by `@Order(n)` value
`MethodName`	Alphabetical by method name
`DisplayName`	Alphabetical by display name
`Random`	Pseudo-random (seed configurable)

JUnit: explicit test ordering with @Order

@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
class UserWorkflowTest {

    @Test @Order(1)
    void createUser() { /* ... */ }

    @Test @Order(2)
    void updateUserProfile() { /* ... */ }

    @Test @Order(3)
    void deleteUser() { /* ... */ }
}

However, JUnit intentionally does not support test dependencies. If createUser() fails, updateUserProfile() still runs. This reflects JUnit’s philosophy that tests should be independent and isolated.

TestNG: dependencies as a first-class concept

TestNG lets you declare explicit dependencies between tests using dependsOnMethods or dependsOnGroups. If a prerequisite test fails, dependent tests are automatically skipped rather than producing misleading failures.

TestNG: test dependencies that skip on prerequisite failure

@Test
public void createUser() { /* ... */ }

@Test(dependsOnMethods = "createUser")
public void updateUserProfile() { /* ... */ }

@Test(dependsOnMethods = "updateUserProfile")
public void deleteUser() { /* ... */ }

Bottom line: JUnit supports ordering but enforces test independence. TestNG supports both ordering and dependencies, which is valuable for integration and end-to-end test workflows where sequential steps depend on prior state.

Parallel execution

Both frameworks support parallel test execution, but differ in configuration approach.

JUnit configures parallelism through junit-platform.properties:

JUnit: enabling parallel execution

junit.jupiter.execution.parallel.enabled = true
junit.jupiter.execution.parallel.mode.default = concurrent
junit.jupiter.execution.parallel.mode.classes.default = concurrent

TestNG configures parallelism directly in the XML suite file, with granular control over thread count and parallel scope (methods, classes, tests, or instances):

TestNG: parallel execution via XML suite

<suite name="Parallel Suite" parallel="classes" thread-count="8">
    <test name="All Tests">
        <packages>
            <package name="com.example.tests" />
        </packages>
    </test>
</suite>

Bottom line: TestNG’s XML-based parallel configuration is more expressive and easier to adjust per suite without touching code. JUnit’s properties-file approach is simpler but less granular.

Reporting

JUnit produces XML reports (consumed by CI tools like Jenkins) and relies on build tool plugins (Maven Surefire Report, Gradle test reports) for HTML output. The reports are functional and well-supported.

TestNG generates detailed HTML reports out of the box, including pass/fail percentages, execution times, retry counts, and per-group breakdowns. For teams that want rich test reporting without additional tooling, TestNG has an edge.

Build tool and CI/CD integration

Both frameworks integrate seamlessly with Maven (via Surefire/Failsafe plugins) and Gradle. Both work with all major CI/CD platforms: Jenkins, GitHub Actions, GitLab CI, CircleCI, and others. Neither framework presents a significant integration advantage over the other in this area.

Note: When using Maven Surefire with recent versions, it automatically detects your testing framework from project dependencies. Explicitly specifying a framework in Surefire’s plugin dependencies can reduce its capabilities and may affect test grouping and coverage calculations.

When to use JUnit

Unit testing: JUnit’s strength is testing isolated components. Its design encourages independent, fast-running tests.
Test-driven development (TDD): JUnit’s quick feedback loop and simple annotation model are ideal for red-green-refactor cycles.
Greenfield projects on Java 17+: JUnit 6 brings modern features like native Kotlin support and unified versioning.
Team familiarity: With ~62% adoption across Java projects, most developers already know JUnit.
Spring Boot projects: Spring’s test framework is built on JUnit, with @SpringBootTest, @WebMvcTest, and other annotations targeting JUnit directly.

When to use TestNG

Integration and end-to-end testing: TestNG’s dependency management and group execution simplify complex multi-step test workflows.
Selenium-based UI automation: TestNG remains the preferred framework in the Selenium automation community for its parallel execution, grouping, and retry capabilities.
Complex data-driven testing: When you need reusable @DataProvider methods shared across test classes with external data sources.
Large test suite orchestration: XML suite files provide centralized control over what runs, when, and how.
Legacy enterprise projects: Many enterprise automation frameworks are built on TestNG. Migration may not be worth the effort.

Using both frameworks together

Many teams use JUnit for unit tests and TestNG for integration or system-level tests within the same project. This is a valid approach. Both frameworks coexist through Maven or Gradle dependency scoping, and CI pipelines can execute them in separate phases.

Automating test creation with Diffblue Cover

Regardless of which framework you choose, writing comprehensive unit tests is time-consuming. Diffblue Cover is an AI-powered tool that automatically generates human-readable Java unit tests for both JUnit and TestNG projects.

Framework support

Diffblue Cover auto-detects your project’s testing framework and version from the classpath. It supports:

JUnit 4: versions 4.11 to 4.13
JUnit Jupiter 5: versions 5.0 to 5.12.2
JUnit 6: for projects on Java 17 and higher
TestNG: versions 6.0.1 to 7.10.2

You can also explicitly specify the framework using the CLI:

Specifying the test framework with Diffblue Cover CLI

# Auto-detect (default behavior)
dcover create

# Force JUnit 5
dcover create --test-framework=junit-5

# Force TestNG
dcover create --test-framework=testng-7.8

# Generate tests for a specific class
dcover create com.example.service.OrderService

How it works

Cover analyzes your project’s bytecode, runs your code in a secure sandbox, and produces tests that compile, execute, and validate the current behavior. It generates tests following standard patterns (Arrange-Act-Assert) with meaningful assertions. Cover is available as:

Cover Plugin: Write tests with one click directly in IntelliJ IDEA.
Cover CLI: Generate tests across entire projects from the command line.
Cover Pipeline: Integrate automated test generation into your CI/CD pipeline.

Practical use case: establishing a test baseline

When adopting either framework on a project with low test coverage, Diffblue Cover can generate a comprehensive test baseline in minutes rather than weeks. This is especially valuable before major refactoring or framework upgrades, where unit tests serve as regression guards to verify that behavior is preserved. See the verified application modernization tutorial for a step-by-step walkthrough.

Conclusion

JUnit and TestNG solve different problems well. JUnit is the standard for focused, independent unit tests and fits naturally into TDD workflows and Spring Boot projects. TestNG excels at complex test orchestration where dependencies, grouping, parallel execution, and data-driven scenarios matter most.

Key takeaways:

JUnit 6 is current: Requires Java 17+, brings Kotlin-native support and unified versioning. JUnit 5 remains the choice for Java 8-16 projects.
JUnit supports test ordering: @TestMethodOrder with four built-in orderers, but not test dependencies (by design).
TestNG shines for integration testing: Dependencies, XML suite orchestration, and built-in parallel execution make complex workflows manageable.
You can use both: JUnit for unit tests, TestNG for integration tests is a common and valid pattern.
AI-generated tests work with both: Tools like Diffblue Cover support JUnit 4/5/6 and TestNG, removing framework choice as a barrier to test coverage.

JUnit vs TestNG: a practical comparison for Java teams

Author

JUnit vs TestNG: a practical comparison for Java teams

Quick-reference comparison table

Annotation mapping: JUnit 4 vs JUnit 5/6 vs TestNG

What changed recently: JUnit 6 and TestNG 7.11

JUnit 6: key changes

TestNG 7.11: incremental improvements

Test organization and grouping

JUnit: tags and suites

TestNG: groups and XML suites

Parameterized and data-driven testing

JUnit: multiple argument sources

TestNG: DataProvider annotation

Test execution order and dependencies

JUnit: ordered but independent

TestNG: dependencies as a first-class concept

Parallel execution

Reporting

Build tool and CI/CD integration

When to use JUnit

When to use TestNG

Using both frameworks together

Automating test creation with Diffblue Cover

Framework support

How it works

Practical use case: establishing a test baseline

Conclusion

References

Framework documentation

Diffblue resources

FAQ

Does JUnit 6 replace JUnit 5?

Can Diffblue Cover generate TestNG tests for a project that also uses JUnit?

Is TestNG losing relevance?

What about Spock or other alternatives?

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