TestNG is one of the most popular testing frameworks used for Java-based automation, making it a key topic in QA interviews. Interviewers often focus on how well candidates understand annotations, grouping, test configuration, and parallel execution in TestNG. This blog brings together the top 25+ TestNG interview questions and answers asked in 2025. Each question is designed to help clarify core concepts and real-world use cases.
Go through this list to brush up on your TestNG knowledge and prepare effectively for your next QA or automation interview.
Fun Fact – As of 2025, TestNG is the 6th most used testing framework on Maven, with over 12,000 dependent artifacts.
Note – We have categorized the TestNG interview questions into three sections – Basic, For Freshers, and For Experienced Professionals to help you navigate and prepare better based on your skill level.
Basic TestNG Framework Interview Questions
Here is a list of basic TestNG interview questions and answers.
- What is TestNG, and how does it differ from other testing frameworks?
TestNG (Test Next Generation) is a testing framework inspired by JUnit and NUnit but designed to be more flexible and powerful. It supports parallel test execution, data-driven testing, test configuration, and annotations. Unlike JUnit, it allows grouping and prioritizing tests without needing multiple classes.
- What are the key features of TestNG?
Some key features include:
- Flexible test configuration using XML
- Support for parallel execution and multi-threading
- Powerful annotation-based test structure
- Integration with tools like Maven, Jenkins, and Selenium
- Support for parameterization and data-driven testing
- How do you install TestNG in Eclipse?
Go to Help > Eclipse Marketplace, search for “TestNG,” and install it. After restarting Eclipse, TestNG options will be available under the New TestNG Class wizard. You can also install it via the update site URL if needed.
- Explain the execution flow of TestNG annotations.
A typical order is: @BeforeSuite → @BeforeTest → @BeforeClass → @BeforeMethod → @Test → @AfterMethod → @AfterClass → @AfterTest → @AfterSuite.
Each controls different stages of test execution—suite level, class level, method level, etc.
- What is the purpose of the testng.xml file in TestNG?
It is used to define test suites, control the order of test execution, group tests, include/exclude methods, and enable parallel execution. It helps manage test runs without changing the code.
Also Read - Top 20 Robot Framework Interview Questions and Answers
TestNG Interview Questions for Freshers
Here are some commonly asked TestNG interview questions and answers for freshers.
- How do you create and run a basic TestNG test case?
Create a Java class, add the @Test annotation to a method, then run it as a TestNG test. TestNG automatically executes all methods marked with @Test.
- What are the different types of assertions available in TestNG?
Some common assertions are:
- assertEquals()
- assertTrue()
- assertFalse()
- assertNull()
- assertNotNull()
They help validate expected outcomes during test execution.
- How can you disable a test case in TestNG?
Use the enabled=false attribute in the @Test annotation:
@Test(enabled = false)
- What is the default priority of test methods in TestNG, and how can it be changed?
By default, TestNG runs test methods in alphabetical order. You can change this using the priority attribute in the @Test annotation:
@Test(priority = 1)
- Explain the concept of data providers in TestNG.
@DataProvider is used for data-driven testing. It feeds multiple sets of data to the same test method. It returns a two-dimensional Object[][] array, allowing the same test to run multiple times with different inputs.
TestNG Interview Questions for Experienced
Let’s go through some important TestNG interview questions and answers for experienced professionals.
- How do you perform parallel test execution in TestNG?
Use the parallel attribute in testng.xml. Set it to “methods”, “classes”, or “tests”, and define thread-count. This helps reduce execution time.
Example:
<suite name=”Suite” parallel=”tests” thread-count=”2″>
- What are TestNG listeners, and how do you implement them?
Listeners let you monitor test execution events. Implement interfaces like ITestListener or ISuiteListener. Then register the listener in testng.xml or use the @Listeners annotation.
- How can you handle dependencies between test methods in TestNG?
Use dependsOnMethods in the @Test annotation. The dependent test will only run if the specified method passes.
- Explain how to generate custom reports in TestNG.
Implement the IReporter or ITestListener interface and override methods like onTestSuccess, onTestFailure, etc. This allows logging and formatting results as needed.
- What is the use of the @Factory annotation in TestNG?
@Factory is used to run the same test class with different sets of data or configurations. It returns an array of test class instances for dynamic execution.
TestNG Interview Questions for 2 Years Experienced
- How do you group test cases in TestNG, and what is the benefit?
- What is the significance of the @Parameters annotation in TestNG?
- How can you rerun failed tests in TestNG?
TestNG Interview Questions for 5 Years Experienced
- Describe the process of integrating TestNG with build tools like Maven or Gradle.
- How do you implement parallel execution at the suite level in TestNG?
- What strategies do you use to manage large test suites in TestNG?
Also Read - Top 20 Maven Interview Questions and Answers
Selenium TestNG Interview Questions
These are some important TestNG Selenium interview questions and answers.
- How do you integrate Selenium WebDriver tests with TestNG?
Write Selenium test steps inside methods annotated with @Test. Add the TestNG library to your project, then use a test runner or testng.xml to execute the tests. This setup supports assertions, reporting, and test grouping.
- What are the advantages of using TestNG with Selenium?
TestNG simplifies test execution, allows grouping of tests, parallel execution, flexible configuration using XML, and better reporting compared to plain Selenium scripts.
- How can you perform cross-browser testing using TestNG with Selenium?
You might also come across TestNG in Selenium interview questions like this one.
Use the @Parameters annotation with testng.xml to pass browser names. Based on the parameter value, initialize the respective WebDriver (ChromeDriver, FirefoxDriver, etc.).
- Explain how to parameterize Selenium tests using TestNG.
Use either @Parameters (for single values via testng.xml) or @DataProvider (for multiple sets of data). @DataProvider allows more dynamic control over inputs.
- How do you handle test dependencies in Selenium TestNG tests?
Use dependsOnMethods to define test execution order. If one test relies on the result of another (e.g., login before checkout), this ensures proper flow.
Also Read - Top 70+ Selenium Interview Questions and Answers
TestNG Annotations Interview Questions
These are some frequently asked TestNG interview questions on annotations.
- What is the difference between @BeforeMethod and @BeforeTest annotations in TestNG?
@BeforeMethod runs before each @Test method inside a class.
@BeforeTest runs once before any test in a <test> tag from testng.xml executes.
So, @BeforeMethod is method-level, while @BeforeTest is suite-level.
- How does the @DataProvider annotation work in TestNG?
It provides a way to pass multiple sets of data to a test method. It returns an Object[][] array, and each row is used as input for a separate execution of the test.
- Explain the use of @BeforeSuite and @AfterSuite annotations.
@BeforeSuite runs once before any test in the suite begins.
@AfterSuite runs once after all tests in the suite finish.
They are useful for setting up or cleaning up global resources like DB connections or reports.
- What is the purpose of the @Listener annotation in TestNG?
@Listener is used to hook into the test execution lifecycle. By implementing interfaces like ITestListener, you can capture events like test success, failure, or skip—and use them for logging or reporting.
- How can you create a custom annotation in TestNG?
You can define your own Java annotation using @interface, but TestNG doesn’t automatically recognize it. To use it with TestNG, you’d need to pair it with custom logic (like reflection or listeners) to process it.
Also Read - Top 70+ Automation Testing Interview Questions and Answers
Wrapping Up
With these top 25+ TestNG interview questions and answers, you’ll be better prepared to face technical interviews with confidence. From basic concepts to real-world scenarios, this guide covers what matters.
Looking for TestNG jobs? Find the best opportunities on Hirist—an online job portal made for tech professionals. Explore top TestNG roles across India quickly and easily.
Also Read - Top 25+ Java Questions for Selenium Interview
FAQs
Are TestNG questions asked in automation testing interviews?
Yes, especially if you use Java with Selenium. Interviewers often ask about TestNG annotations, test execution flow, test grouping, and data providers during automation interviews.
What is the best way to prepare for TestNG interview questions?
Practice writing TestNG tests in a sample framework. Focus on annotations, dependencies, and real-time use with Selenium. Review commonly asked questions before your interview.
How to explain TestNG in an interview?
TestNG is a Java-based testing framework. It helps organize tests using annotations. It supports grouping, priorities, parallel execution, and better reporting compared to older frameworks like JUnit.
Should freshers learn TestNG for QA interviews?
Yes. TestNG is beginner-friendly and widely used in test automation. Learning it helps freshers understand structured test execution and prepare better for entry-level QA roles.
Is TestNG still relevant in 2025?
Absolutely. TestNG is actively used in Java-based automation frameworks. It supports parallel testing, reporting, and easy integration with Selenium, Maven, and CI tools like Jenkins.
Also Read - Top 45+ Jenkins Interview Questions and Answers
Do I need to know testng.xml for interviews?
Yes. Knowing testng.xml helps you answer questions on test configuration, grouping, browser parameterization, and parallel test execution. It’s often a common interview topic.
What is the difference between @Factory and @DataProvider annotation?
@Factory creates multiple test class instances. It’s used for class-level parameterization.
@DataProvider supplies data to test methods. It’s used for running the same test with different inputs.
What is the main use of TestNG?
TestNG helps run, manage, and structure test cases in automation. It supports annotations, parallel runs, dependencies, and flexible configurations using XML or code.
What is the average salary for TestNG automation testers in India?
In 2025, automation testers with TestNG skills earn between ₹5–12 LPA. Salaries vary based on experience, location, and additional tools like Selenium or Jenkins.
