TestNG vs JUnit 5: Which Java Testing Framework in 2026?

Choosing between TestNG and JUnit 5 is one of the most common decisions Java teams face when setting up their testing strategy. Both frameworks are mature, well-maintained, and capable of supporting enterprise-grade test suites. This guide provides a comprehensive comparison to help you make an informed choice based on your project needs, team expertise, and testing requirements.

Key Takeaways

JUnit 5 is the default choice for new projects due to its modular architecture, extension model, and broader ecosystem support
TestNG excels in complex test orchestration scenarios with its XML suite configuration, dependency management, and built-in data providers
JUnit 5 parameterized tests require less boilerplate than TestNG data providers for simple cases, but TestNG data providers offer more flexibility for complex scenarios
Both frameworks support parallel execution, but TestNG offers more granular control via XML configuration out of the box
Migration from TestNG to JUnit 5 is straightforward for most test suites with a clear annotation mapping
AI coding agents with QA skills from qaskills.sh can generate tests for either framework following best practices

Feature Comparison Table

Feature	JUnit 5	TestNG
Architecture	Modular (Platform + Jupiter + Vintage)	Monolithic JAR
Annotations	`@Test`, `@BeforeEach`, `@AfterEach`	`@Test`, `@BeforeMethod`, `@AfterMethod`
Parameterized Tests	`@ParameterizedTest` with multiple sources	`@DataProvider`
Nested Tests	`@Nested` inner classes	Not supported natively
Parallel Execution	Via properties file	Via XML suite configuration
Test Dependencies	Not supported (by design)	`@Test(dependsOnMethods)`
Suite Configuration	Via `@Suite` or build tool	XML suite files
Test Groups	`@Tag`	`@Test(groups)`
Soft Assertions	`assertAll()`	`SoftAssert` class
Extension Model	`@ExtendWith` (composable)	Listeners and `@Listeners`
Retry Failed Tests	Via extensions	`@Test(retryAnalyzer)` built-in
Default Test Timeout	`@Timeout` annotation	`@Test(timeOut)` attribute
IDE Support	Excellent (all major IDEs)	Excellent (all major IDEs)
Spring Boot Default	Yes (default dependency)	Requires manual setup
Community Size	Larger	Smaller but active

Annotations Comparison

Understanding the annotation mapping between the two frameworks is essential for migration and for teams working with both.

JUnit 5 Annotations

import org.junit.jupiter.api.*;

class JUnit5Example {

    @BeforeAll
    static void beforeAll() { /* once before all tests */ }

    @BeforeEach
    void beforeEach() { /* before each test */ }

    @Test
    @DisplayName("descriptive test name")
    void testMethod() { /* test logic */ }

    @Test
    @Disabled("reason for skipping")
    void skippedTest() { /* skipped */ }

    @AfterEach
    void afterEach() { /* after each test */ }

    @AfterAll
    static void afterAll() { /* once after all tests */ }
}

TestNG Annotations

import org.testng.annotations.*;

class TestNGExample {

    @BeforeSuite
    void beforeSuite() { /* once before entire suite */ }

    @BeforeClass
    void beforeClass() { /* once before this class */ }

    @BeforeMethod
    void beforeMethod() { /* before each test */ }

    @Test(description = "descriptive test name")
    void testMethod() { /* test logic */ }

    @Test(enabled = false)
    void skippedTest() { /* skipped */ }

    @AfterMethod
    void afterMethod() { /* after each test */ }

    @AfterClass
    void afterClass() { /* once after this class */ }

    @AfterSuite
    void afterSuite() { /* once after entire suite */ }
}

Annotation Mapping Reference

Purpose	JUnit 5	TestNG
Test method	`@Test`	`@Test`
Before each test	`@BeforeEach`	`@BeforeMethod`
After each test	`@AfterEach`	`@AfterMethod`
Before all tests	`@BeforeAll`	`@BeforeClass`
After all tests	`@AfterAll`	`@AfterClass`
Disable test	`@Disabled`	`@Test(enabled = false)`
Timeout	`@Timeout(5)`	`@Test(timeOut = 5000)`
Tag/Group	`@Tag("smoke")`	`@Test(groups = "smoke")`

Parameterized Tests vs Data Providers

This is one of the biggest practical differences between the two frameworks.

JUnit 5 Parameterized Tests

@ParameterizedTest
@DisplayName("should validate email format")
@CsvSource({
    "user@example.com, true",
    "invalid-email, false",
    "user@, false",
    "user@domain.co.uk, true"
})
void shouldValidateEmail(String email, boolean expected) {
    assertEquals(expected, validator.isValid(email));
}

@ParameterizedTest
@MethodSource("orderTestData")
void shouldCalculateOrderTotal(
        List<Item> items, double discount, double expected) {
    Order order = new Order(items);
    order.applyDiscount(discount);
    assertEquals(expected, order.getTotal(), 0.01);
}

static Stream<Arguments> orderTestData() {
    return Stream.of(
        Arguments.of(
            List.of(new Item("A", 10.0), new Item("B", 20.0)),
            0.0, 30.0),
        Arguments.of(
            List.of(new Item("A", 10.0), new Item("B", 20.0)),
            0.1, 27.0),
        Arguments.of(
            List.of(new Item("C", 100.0)),
            0.5, 50.0)
    );
}

TestNG Data Providers

@DataProvider(name = "emailData")
public Object[][] emailData() {
    return new Object[][] {
        {"user@example.com", true},
        {"invalid-email", false},
        {"user@", false},
        {"user@domain.co.uk", true}
    };
}

@Test(dataProvider = "emailData")
public void shouldValidateEmail(String email, boolean expected) {
    assertEquals(expected, validator.isValid(email));
}

// Data provider from a separate class
@Test(dataProvider = "orderData",
      dataProviderClass = OrderDataProviders.class)
public void shouldCalculateTotal(
        List<Item> items, double discount, double expected) {
    Order order = new Order(items);
    order.applyDiscount(discount);
    assertEquals(expected, order.getTotal(), 0.01);
}

// Lazy data provider using Iterator
@DataProvider(name = "largeDataset")
public Iterator<Object[]> largeDataset() {
    return Files.lines(Path.of("testdata.csv"))
        .map(line -> line.split(","))
        .map(parts -> new Object[]{parts[0], parts[1]})
        .iterator();
}

Verdict: JUnit 5 parameterized tests are more concise for simple cases with @CsvSource and @ValueSource. TestNG data providers are more flexible for complex scenarios, especially when data comes from external sources or needs to be shared across test classes.

Parallel Execution

JUnit 5 Parallel Execution

# junit-platform.properties
junit.jupiter.execution.parallel.enabled=true
junit.jupiter.execution.parallel.mode.default=concurrent
junit.jupiter.execution.parallel.mode.classes.default=concurrent
junit.jupiter.execution.parallel.config.strategy=fixed
junit.jupiter.execution.parallel.config.fixed.parallelism=4

// Opt specific tests out of parallel execution
@Execution(ExecutionMode.SAME_THREAD)
class SequentialDatabaseTest {
    @Test
    void testA() { /* runs sequentially */ }

    @Test
    void testB() { /* runs sequentially */ }
}

TestNG Parallel Execution

<!-- testng.xml -->
<suite name="Parallel Suite" parallel="methods" thread-count="4">
    <test name="All Tests">
        <classes>
            <class name="com.example.UserServiceTest"/>
            <class name="com.example.OrderServiceTest"/>
        </classes>
    </test>
</suite>

<!-- More granular control -->
<suite name="Mixed Suite">
    <test name="Sequential Tests" parallel="none">
        <classes>
            <class name="com.example.DatabaseMigrationTest"/>
        </classes>
    </test>
    <test name="Parallel Tests" parallel="methods" thread-count="8">
        <classes>
            <class name="com.example.ApiTest"/>
            <class name="com.example.ValidationTest"/>
        </classes>
    </test>
</suite>

Verdict: TestNG provides more granular control over parallel execution through XML configuration without modifying test code. JUnit 5 parallel execution is configured via properties and annotations, which keeps everything in code but offers less fine-grained suite-level control.

Test Dependencies and Ordering

TestNG Dependencies

public class WorkflowTest {

    @Test(priority = 1)
    public void createUser() {
        // Creates test user
    }

    @Test(priority = 2, dependsOnMethods = "createUser")
    public void loginUser() {
        // Logs in with created user
    }

    @Test(priority = 3, dependsOnMethods = "loginUser")
    public void performAction() {
        // Performs action as logged-in user
    }
}

JUnit 5 Test Ordering

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

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

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

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

Verdict: TestNG has first-class dependency support where a dependent test is automatically skipped if its prerequisite fails. JUnit 5 supports ordering but deliberately does not support dependencies, encouraging independent tests. For workflow testing, TestNG is more natural; for unit testing, JUnit 5's approach prevents fragile test chains.

Reporting

TestNG Built-in Reports

TestNG generates HTML reports by default in the test-output directory, including:

Index page with suite summary
Per-test results with pass/fail/skip counts
Detailed failure information with stack traces
Chronological view of test execution

JUnit 5 Reporting

JUnit 5 relies on build tools and third-party reporters:

// Gradle - Generate XML reports for CI
test {
    useJUnitPlatform()
    reports {
        html.required = true
        junitXml.required = true
    }
}

For richer reports, integrate Allure:

<dependency>
    <groupId>io.qameta.allure</groupId>
    <artifactId>allure-junit5</artifactId>
    <version>2.25.0</version>
    <scope>test</scope>
</dependency>

Verdict: TestNG provides better out-of-the-box reporting. JUnit 5 requires additional setup for rich reports but integrates well with standard CI tools and Allure.

Retry Mechanism

TestNG Retry Analyzer

public class RetryAnalyzer implements IRetryAnalyzer {
    private int count = 0;
    private static final int MAX_RETRY = 2;

    @Override
    public boolean retry(ITestResult result) {
        if (count < MAX_RETRY) {
            count++;
            return true;
        }
        return false;
    }
}

@Test(retryAnalyzer = RetryAnalyzer.class)
public void flakyNetworkTest() {
    // Will retry up to 2 times on failure
}

JUnit 5 Retry via Extension

// Requires a custom extension or third-party library
@RetryingTest(maxAttempts = 3)
void flakyNetworkTest() {
    // Uses junit-pioneer library
}

Verdict: TestNG has built-in retry support. JUnit 5 requires the junit-pioneer library or a custom extension, but the result is equivalent.

When to Choose Each Framework

Choose JUnit 5 When

Starting a new project with Spring Boot (it is the default)
Your team is familiar with the JUnit ecosystem
You want a modular, extensible architecture
You prefer nested test classes for organization
You need broad library and IDE support
You value the principle of independent, isolated tests

Choose TestNG When

You need complex suite orchestration via XML
Test dependencies are a natural fit for your workflow tests
You want built-in retry analysis without third-party libraries
Your team already has TestNG expertise and existing suites
You need fine-grained parallel execution control at the suite level
You rely heavily on data providers from external classes

Migration Guide: TestNG to JUnit 5

For teams migrating from TestNG to JUnit 5, here is a step-by-step approach.

Step 1: Update Dependencies

<!-- Remove TestNG -->
<!-- <dependency>
    <groupId>org.testng</groupId>
    <artifactId>testng</artifactId>
</dependency> -->

<!-- Add JUnit 5 -->
<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter</artifactId>
    <version>5.11.0</version>
    <scope>test</scope>
</dependency>

Step 2: Update Imports and Annotations

// Before (TestNG)
import org.testng.annotations.Test;
import org.testng.annotations.BeforeMethod;
import static org.testng.Assert.assertEquals;

// After (JUnit 5)
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.BeforeEach;
import static org.junit.jupiter.api.Assertions.assertEquals;

Step 3: Convert Data Providers

// Before (TestNG)
@DataProvider
public Object[][] data() {
    return new Object[][] {{"a", 1}, {"b", 2}};
}

@Test(dataProvider = "data")
public void test(String s, int n) { /* ... */ }

// After (JUnit 5)
@ParameterizedTest
@MethodSource("data")
void test(String s, int n) { /* ... */ }

static Stream<Arguments> data() {
    return Stream.of(
        Arguments.of("a", 1),
        Arguments.of("b", 2)
    );
}

Step 4: Convert Assertions

// TestNG assertion order: (actual, expected)
assertEquals(result, "expected");

// JUnit 5 assertion order: (expected, actual)
assertEquals("expected", result);

Note the reversed parameter order. This is the most common source of bugs during migration.

Integrating QA Skills

Whether you use TestNG or JUnit 5, QA skills can accelerate your test authoring:

npx @qaskills/cli add junit5-testing
npx @qaskills/cli add testng-testing

These skills configure your AI coding agent to generate tests following each framework's conventions and best practices.

10 Best Practices (Both Frameworks)

Keep tests independent. Each test should set up and tear down its own state. Test ordering and dependencies are code smells in unit tests.
Use meaningful names. @DisplayName in JUnit 5 or description in TestNG makes test reports human-readable.
One logical assertion per test. Multiple assertions checking different behaviors should be separate test methods.
Prefer composition over inheritance. Use JUnit 5 extensions or TestNG listeners instead of deep test class hierarchies.
Parameterize repetitive tests. If three tests differ only by input data, use parameterized tests or data providers.
Mock external dependencies. Database calls, API calls, and file system operations should be mocked in unit tests.
Run tests in parallel. Design tests for concurrent execution from the start. Fix shared state issues early.
Fail fast with clear messages. Custom assertion messages should explain what went wrong, not just that something failed.
Measure and monitor test execution time. Slow tests indicate design problems. Track test suite duration in CI.
Review tests in code reviews. Test code deserves the same review rigor as production code.

8 Anti-Patterns to Avoid

Mixing JUnit 4 and JUnit 5 annotations. Importing @Test from the wrong package silently skips tests. Be consistent across the codebase.
Using test dependencies as a shortcut for setup. dependsOnMethods in TestNG should not replace proper @BeforeMethod setup. Dependencies couple tests and cause cascading failures.
Asserting on toString() output. Comparing string representations is fragile. Assert on specific properties instead.
Testing implementation details. Tests should verify behavior, not internal state. Refactoring should not break tests unless behavior changes.
Ignoring flaky tests. A flaky test is worse than no test because it erodes confidence in the suite. Fix or remove flaky tests immediately.
Hardcoding test data. Magic numbers and strings scattered through tests make them unreadable. Use constants, builders, or factory methods.
Writing integration tests disguised as unit tests. If your "unit test" needs a database, network, or file system, it is an integration test. Label and isolate it accordingly.
Skipping cleanup. Tests that create files, database records, or external resources must clean up after themselves, even when they fail.

Conclusion

Both TestNG and JUnit 5 are excellent Java testing frameworks. JUnit 5 is the better default choice for most new projects due to its modular design, broader ecosystem integration, and the fact that Spring Boot includes it out of the box. TestNG remains a strong choice for teams that need complex suite orchestration, built-in dependency management, and granular parallel execution control. Regardless of your choice, the fundamentals of good testing remain the same: isolated tests, clear assertions, and fast feedback loops. Use QA skills from qaskills.sh to ensure your AI coding agents generate tests that follow whichever framework's best practices your team adopts.