100 Automation testing interview questions with their answers:

1. What is Automation Testing?

Automation Testing is the process of using specialized software tools and scripts to automate the execution of test cases, reducing manual effort and time taken for testing.

2. What are the advantages of Automation Testing?

• Faster test execution
• Reusability of test scripts
• Improved accuracy and reliability
• Supports multiple platforms and browsers
• Ideal for regression and repetitive testing

3. What are the disadvantages of Automation Testing?

• High initial setup cost for tools and infrastructure
• Requires skilled resources to write and maintain scripts
• Not suitable for exploratory testing
• Maintenance overhead when the application changes frequently

4. What is Selenium?

Selenium is an open-source, portable framework used for automating web applications. It supports various programming languages such as Java, C#, Python, and Ruby.

5. What are the components of Selenium?

• Selenium WebDriver: For browser automation.
• Selenium IDE: A browser plugin used for recording and playing back tests.
• Selenium Grid: For running tests in parallel across multiple machines and environments.

6. What is Selenium WebDriver?

Selenium WebDriver is a tool for automating web browsers. It provides an API to interact with browsers and perform actions like clicking buttons, entering text, and validating content.

7. What is the difference between Selenium WebDriver and Selenium RC?

• WebDriver: Communicates directly with the browser and does not require a server.
• RC: Requires a server that intermediates between the browser and the testing script.

8. What is the purpose of XPath in Selenium?

XPath is used to locate elements in the DOM (Document Object Model) using a query syntax. It helps navigate through elements and attributes in an XML document, and it is often used in Selenium for element identification.

9. What is the difference between XPath and CSS Selectors?

• XPath: XPath is used to navigate through elements in an XML document, offering flexibility in finding elements with specific attributes.
• CSS Selectors: A simpler and faster way to locate elements based on CSS attributes (e.g., class, id).

10. What is TestNG?

TestNG is a testing framework inspired by JUnit, designed for test configuration and parallel execution. It provides powerful features like test grouping, parameterization, and data-driven testing.

11. What is the difference between TestNG and JUnit?

• TestNG: Supports parallel execution, test configuration, data-driven testing, and annotations.
• JUnit: Primarily designed for unit testing, and lacks some of the advanced features of TestNG.

12. What is the role of assertions in Automation Testing?

Assertions validate whether the expected result matches the actual result. If the condition is false, the test fails. Examples: assertTrue(), assertFalse(), assertEquals().

13. What are Test Annotations in TestNG?

TestNG annotations are used to define the test methods' behavior and execution order. Common annotations include:

• @Test: Marks a method as a test method.
• @BeforeTest: Executed before any test is run.
• @AfterTest: Executed after all tests are run.

14. What is Parallel Test Execution in TestNG?

Parallel Test Execution allows running multiple test methods, classes, or suites simultaneously, reducing the time taken to execute tests.

15. What is the difference between @BeforeClass and @BeforeMethod in TestNG?

• @BeforeClass: Executes once before the first method in the class.
• @BeforeMethod: Executes before each test method in the class.

16. What is Selenium Grid?

Selenium Grid is used for executing Selenium tests across multiple machines and browsers simultaneously, enabling parallel test execution.

17. What is the Page Object Model (POM)?

Page Object Model (POM) is a design pattern used to create object-oriented classes that serve as an interface to the web page. It helps maintain a clean and scalable code structure by separating page-specific actions from test scripts.

18. What is a Data-Driven Testing approach?

Data-Driven Testing involves running the same test with multiple sets of input data to validate how the application handles different data inputs.

19. What are the benefits of using Selenium for Automation Testing?

• Open-source
• Supports multiple browsers
• Compatible with multiple programming languages
• Can be integrated with other tools like TestNG, JUnit, Jenkins, and Maven.

20. How do you handle dynamic elements in Selenium?

Dynamic elements can be handled by using:

• XPath with contains()
• CSS Selectors with dynamic attributes
• Explicit Waits to wait for elements to load completely

21. What is the difference between Implicit Wait and Explicit Wait in Selenium?

• Implicit Wait: Sets a default wait time for all elements.
• Explicit Wait: Waits for a specific condition (e.g., element visibility) before proceeding with the next action.

22. What is the difference between a test case and a test script?

• Test Case: A set of conditions or steps to verify a specific feature of the application.
• Test Script: A piece of code written to automate the execution of the test case.

23. What is Continuous Integration (CI) in Automation Testing?

Continuous Integration involves integrating code into a shared repository frequently. Automation testing tools are used to run test cases after each code commit to ensure the system’s stability.

24. What is the role of Jenkins in Automation Testing?

Jenkins is an open-source automation server that supports continuous integration. It automates the process of building, testing, and deploying applications.

25. What are the challenges of Automation Testing?

• High initial setup cost
• Complexity in maintaining test scripts
• Handling dynamic elements
• Not suitable for ad-hoc testing or exploratory testing

26. What is a Locator in Selenium?

A Locator is an object or strategy used to find an element on a web page. Common locators include ID, Name, Class Name, CSS Selector, XPath, etc.

27. What is Headless Testing?

Headless Testing involves running tests without a graphical user interface. It’s faster and uses fewer resources, ideal for continuous integration environments.

28. How do you handle multiple windows or tabs in Selenium?

Use driver.getWindowHandles() to get the handles of all open windows and then switch to the desired window using driver.switchTo().window(windowHandle).

29. What is the difference between "findElement()" and "findElements()" in Selenium?

• findElement(): Finds a single element and returns a WebElement. If not found, it throws NoSuchElementException.
• findElements(): Returns a list of WebElements. If no element is found, it returns an empty list.

30. What is the difference between a WebDriver and a RemoteWebDriver?

• WebDriver: Used to automate browser actions directly.
• RemoteWebDriver: A subclass of WebDriver that is used for running tests on remote machines (like Selenium Grid).

31. What is a Synchronization issue in Automation Testing?

Synchronization issues occur when a script tries to interact with an element before it is ready. This can be handled using waits, such as Thread.sleep(), implicit wait, and explicit wait.

32. What is an Assertion in Selenium?

An assertion is a statement used to verify if the actual result matches the expected result. If the assertion fails, the test is marked as failed.

33. What is the difference between Assert and Verify in Selenium?

• Assert: If an assertion fails, it immediately stops the execution of the test.
• Verify: If a verification fails, the test continues executing, and the failure is recorded.

34. What is Selenium IDE?

Selenium IDE (Integrated Development Environment) is a Firefox and Chrome plugin used for recording and playing back user interactions with the web application. It’s often used for creating quick and simple test scripts.

35. What is a Test Case in Automation Testing?

A Test Case in Automation Testing refers to a series of actions, inputs, and expected results that define a particular scenario to be automated.

36. What is Browser Compatibility Testing?

Browser Compatibility Testing ensures that the application works correctly across different browsers (e.g., Chrome, Firefox, Safari, IE) and browser versions.

37. What is the importance of version control in Automation Testing?

Version control helps manage changes to automation scripts, track modifications, and collaborate with other team members without conflicts.

38. What is Appium?

Appium is an open-source mobile application automation tool that supports both Android and iOS apps. It allows for writing tests in multiple programming languages.

39. What is BDD (Behavior-Driven Development)?

BDD is a software development approach that encourages collaboration between developers, testers, and non-technical stakeholders. It uses natural language constructs (like Gherkin) to write tests.

40. What is Cucumber?

Cucumber is a BDD testing tool that uses Gherkin syntax to define tests in a human-readable format. It is used to write automated acceptance tests in a domain-specific language.

41. What is the difference between Data-Driven Testing and Keyword-Driven Testing?

• Data-Driven Testing: Focuses on testing a function with multiple sets of data inputs.
• Keyword-Driven Testing: Uses a set of predefined keywords for actions to be performed during the test execution.

42. What are the challenges of Data-Driven Testing?

• Maintenance of large datasets
• Complexity in managing and synchronizing data
• Handling complex input validation
• Managing the mapping of data with corresponding tests

43. What is an Automation Framework?

An Automation Framework is a set of guidelines, concepts, and best practices used for automating testing. It can include test case management, reusable code, data handling, and reporting.

44. What is the Page Factory in Selenium?

Page Factory is a Selenium class used for initializing web elements that are located using Page Object Model (POM). It improves the performance of test execution by initializing elements only when needed.

45. What are the different types of Automation Frameworks?

• Linear Scripting Framework: Simple scripting without any modularity or reusable components.
• Modular Framework: Breaks the tests into smaller, independent modules.
• Data-Driven Framework: Data is separated from the test scripts and fed into the tests.
• Keyword-Driven Framework: Tests are written using keywords to represent actions.
• Hybrid Framework: Combines features of multiple frameworks (e.g., data-driven and keyword-driven).

46. What is the role of Jenkins in Automation Testing?

Jenkins is used for continuous integration and automates the execution of test scripts whenever there is a code change. It helps ensure that the system is tested frequently during the development cycle.

47. How do you perform parallel test execution in Selenium?

Parallel execution can be achieved using:

• TestNG Parallel Execution: Using @Test annotations with a parallel attribute.
• Selenium Grid: Running tests in parallel on multiple machines and browsers.

48. What is a Test Runner in Selenium?

A Test Runner is a component or tool that orchestrates the execution of multiple test cases or test scripts. In the context of Selenium, TestNG or JUnit is often used as a Test Runner.

49. What is an Object Repository in Automation Testing?

An Object Repository is a central place where locators (IDs, names, XPath, CSS Selectors, etc.) are stored for easy reuse in automation scripts, reducing the duplication of locator code.

50. What are the benefits of using Selenium Grid?

• Allows parallel test execution
• Supports multiple browsers and platforms
• Reduces the time for running tests
• Scalable by adding more nodes

51. How do you handle alerts in Selenium?

Selenium provides methods like switchTo().alert() to handle JavaScript alerts, including:

• accept() to click "OK"
• dismiss() to click "Cancel"
• getText() to retrieve alert text
• sendKeys() to enter text into prompt alerts

52. What is the difference between findElement() and findElements()?

• findElement(): Returns a single WebElement; throws NoSuchElementException if the element is not found.
• findElements(): Returns a list of WebElements (may be empty if not found).

53. What is an explicit wait in Selenium?

An explicit wait makes the WebDriver wait for a certain condition to be met before proceeding. Example:

WebDriverWait wait = new WebDriverWait(driver, 10);
wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("element")));

54. What is a synchronous test in automation?

A synchronous test is one where the execution of the test happens in a specific order, and each step is completed before moving to the next.

55. What is the difference between “assert” and “verify” in Selenium?

• Assert: If the assertion fails, the test case stops immediately.
• Verify: The test case continues even if the verification fails, recording the failure.

56. What is the difference between WebDriver and RemoteWebDriver?

• WebDriver: Automates the browser directly.
• RemoteWebDriver: Extends WebDriver to support remote execution, commonly used with Selenium Grid.

57. What is a headless browser?

A headless browser runs without a graphical user interface (GUI), which makes it faster and more suitable for automated testing in CI/CD pipelines. Examples: PhantomJS, Headless Chrome.

58. What is a session in Selenium WebDriver?

A session in WebDriver refers to the interaction between a WebDriver instance and a web browser. Each session is identified by a unique session ID.

59. What is an implicit wait in Selenium?

Implicit wait is used to tell WebDriver to wait for a certain amount of time before throwing a NoSuchElementException. The wait time is applied to all element searches.

driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);

60. What is the difference between driver.get() and driver.navigate().to()?

• driver.get(): Loads a new web page and waits for the page to load completely.
• driver.navigate().to(): Similar to get(), but it can also be used to navigate between browser history (forward, back).

61. How do you handle dynamic elements in Selenium?

Dynamic elements can be handled using:

• XPath with functions: contains(), starts-with()
• CSS Selectors: Matching attributes that change dynamically
• Explicit waits: To ensure elements are ready before interacting with them.

62. What is the role of JavaScript Executor in Selenium?

JavaScript Executor is used to execute JavaScript code within the browser. It is useful for performing tasks that are not directly supported by Selenium WebDriver (e.g., clicking hidden elements).

63. What is the difference between driver.quit() and driver.close()?

• driver.quit(): Closes all the browser windows and ends the WebDriver session.
• driver.close(): Closes the current browser window but does not end the WebDriver session.

64. What is a Locator Strategy?

Locator strategies are used to identify elements on a web page. Common strategies include id, name, xpath, cssSelector, linkText, and partialLinkText.

65. How do you perform actions on mouse events in Selenium?

Selenium provides Actions class to handle mouse events like:

• moveToElement()
• click()
• doubleClick()
• contextClick() (right-click)

66. What is the purpose of the Actions class in Selenium?

The Actions class in Selenium is used to perform complex user interactions such as drag-and-drop, keyboard events, mouse hover, etc.

67. How do you handle file uploads in Selenium?

Selenium does not directly support file uploads. However, you can:

• Use the sendKeys() method to send a file path to an input element of type file.
• Automate file upload using AutoIT or Robot class.

68. What is the Robot class in Java?

The Robot class in Java is used to simulate user input events like keyboard and mouse movements. It is commonly used for automating actions outside the scope of Selenium.

69. How do you handle drop-downs in Selenium?

Drop-downs are handled using the Select class:

Select select = new Select(driver.findElement(By.id("dropdown")));
select.selectByVisibleText("Option");

70. What is a hybrid framework?

A hybrid framework combines features of multiple testing frameworks, such as data-driven, keyword-driven, and modular testing approaches, to leverage their advantages.

71. What is Continuous Delivery in Automation Testing?

Continuous Delivery (CD) involves automatically deploying software after every successful integration to ensure that the product is always ready for release.

72. What are the different types of testing you can automate?

• Regression Testing
• Smoke Testing
• Functional Testing
• Load Testing
• Performance Testing

73. What is Behavior-Driven Development (BDD)?

BDD is an approach to software development that involves writing tests in a language understandable by all stakeholders. It uses frameworks like Cucumber and SpecFlow to define behavior scenarios in a natural language format.

74. What is Cucumber?

Cucumber is a BDD tool that uses the Gherkin syntax to define behavior scenarios in natural language. It allows both technical and non-technical team members to write and understand tests.

75. What is Gherkin?

Gherkin is a language used to write feature files for Cucumber. It defines test scenarios in a natural, human-readable format, typically using Given, When, and Then statements.

76. What is the difference between @BeforeClass and @BeforeMethod in TestNG?

• @BeforeClass: Runs before any test methods in the class.
• @BeforeMethod: Runs before each individual test method

.

77. What is the role of Assert in automation testing?

Assert is used to validate expected outcomes in test cases. If an assertion fails, the test stops immediately and reports a failure.

78. How do you validate test results in Selenium?

Validation can be done using assertions. Examples:

• assertEquals(expected, actual)
• assertTrue(condition)
• assertFalse(condition)

79. What are the types of reports available in TestNG?

• HTML Report
• XML Report
• JUnit Report
• Custom Reports

80. What is the role of the WebElement interface?

The WebElement interface represents elements on a web page and contains methods for performing actions on those elements (e.g., click, send keys, get text).

81. How do you handle AJAX calls in Selenium?

Wait for the AJAX calls to complete using explicit waits or JavaScriptExecutor to check if the AJAX element is loaded.

82. What is the difference between assertTrue and assertFalse in TestNG?

• assertTrue: Passes the test if the condition is true.
• assertFalse: Passes the test if the condition is false.

83. What is a mock object in unit testing?

Mock objects simulate the behavior of real objects to isolate specific units of code during testing.

84. What is a stub in testing?

A stub is a method or component that simulates the behavior of a dependency or function in the system.

85. What is load testing in Selenium?

Load testing measures how an application performs under heavy traffic or load to identify performance bottlenecks.

86. What are the methods for handling synchronization issues in Selenium?

• Implicit Wait
• Explicit Wait
• Thread.sleep()

87. How do you capture a screenshot in Selenium?

Use the TakesScreenshot interface to capture a screenshot:

File screenshot = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
FileUtils.copyFile(screenshot, new File("path_to_save"));

88. What is the role of driver.manage().timeouts()?

This is used to configure the timeouts for implicit wait, page load, and script timeouts.

89. What is the role of WebDriver in Selenium?

WebDriver is used to automate browser interactions. It interacts with web pages and simulates real user behavior for testing purposes.

90. What are JavaScript Executor methods in Selenium?

• executeScript(): Executes JavaScript code in the browser.
• executeAsyncScript(): Executes asynchronous JavaScript.

91. How do you run a test on multiple browsers in Selenium?

Use Selenium Grid or cross-browser testing tools like Sauce Labs or BrowserStack to run tests across multiple browsers.

92. What is Continuous Integration in testing?

Continuous Integration (CI) refers to the practice of frequently integrating code into a shared repository and automatically testing the code.

93. What is the difference between hard assertion and soft assertion in TestNG?

• Hard Assertion: Test fails immediately after the assertion fails.
• Soft Assertion: The test continues even after the assertion fails.

94. How do you perform performance testing in Selenium?

Use tools like JMeter, Gatling, or LoadRunner alongside Selenium for performance testing.

95. What is a Wait in Selenium?

A Wait is used to tell Selenium to wait for certain conditions (e.g., element visibility) before performing further actions.

96. How do you handle dynamic data in Selenium?

Use dynamic XPath or CSS selectors with functions like contains(), starts-with(), or text() to locate elements with changing attributes.

97. What is Robot Class in Selenium?

The Robot class is used to simulate user input events like keyboard and mouse actions.

98. How do you handle file download in Selenium?

Configure browser settings or use libraries like AutoIT to automate file downloads.

99. What is the importance of version control in automation?

Version control helps manage changes to test scripts, maintain different versions, and collaborate with team members effectively.

100. What are the limitations of Automation Testing?

• High initial setup costs
• Maintenance overhead
• Inability to handle exploratory testing
• Limited in handling visual/UI aspects