Top 50 Selenium Interview Question and Answers

1. What is Selenium?
   Selenium is an open-source automation testing tool for web applications. It supports multiple programming languages, including Java, Python, and C#.

2. What are the main components of Selenium?

   • Selenium IDE
   • Selenium WebDriver
   • Selenium Grid

3. What are the advantages of using Selenium?

   • Open-source
   • Multi-language support
   • Cross-browser and cross-platform compatibility
   • Community support

4. What types of applications can Selenium test?
   Selenium is used exclusively for testing web applications and cannot test desktop or mobile apps.

5. What are the limitations of Selenium?

   • Cannot test desktop applications
   • No in-built reporting feature
   • Requires third-party tools for complete automation testing (e.g., for capturing screenshots).

6. What is Selenium WebDriver?
   Selenium WebDriver is an API that interacts with web browsers to automate browser actions like clicking, typing, and navigation.

7. How do you start a browser session in Selenium?

   WebDriver driver = new ChromeDriver();

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

   • driver.get(): Waits for the page to load completely.
   • driver.navigate().to(): Does not wait for page load.

9. How do you handle browser windows in Selenium?
   Use driver.getWindowHandles() to get all open windows’ handles and switch using driver.switchTo().window(handle).

10. How do you handle alerts in Selenium?

    Alert alert = driver.switchTo().alert(); alert.accept(); // To accept the alert

11. How do you find elements in Selenium?
    Using locators like:

• id
• name
• className
• tagName
• cssSelector
• xpath

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

• findElement(): Returns the first matching element or throws an exception if none is found.
• findElements(): Returns a list of matching elements or an empty list if none are found.

1. What are XPath and its types?
   XPath is a syntax used to navigate through elements in an XML document.

• Absolute XPath: Starts from the root (/).
• Relative XPath: Starts from any element (//).

1. How do you handle dynamic elements in Selenium?
   Use dynamic XPath expressions like:

   //*[contains(@id, 'dynamic-part')]

2. How do you perform mouse hover actions in Selenium?

Actions actions = new Actions(driver); actions.moveToElement(element).perform();

1. What is the Page Object Model (POM)?
   POM is a design pattern where web pages are represented as classes, and elements are defined as variables in those classes.

2. What is a Fluent Wait in Selenium?
   Fluent Wait defines the maximum time to wait for a condition and the frequency with which to check the condition.

3. How do you handle frames in Selenium?

   driver.switchTo().frame("frameName");

4. What are Selenium Grid and its usage?
   Selenium Grid is used for parallel test execution across different machines and browsers.

5. What is the difference between implicit wait and explicit wait?

• Implicit Wait: Waits for a specified time for all elements globally.
• Explicit Wait: Waits for a specific condition for a particular element.

1. How do you integrate Selenium with TestNG?
   By using annotations like @Test, @BeforeTest, and @AfterTest in TestNG.

2. What are the benefits of integrating Selenium with Jenkins?

• Continuous Integration and Continuous Deployment (CI/CD)
• Automated execution of Selenium tests

1. How do you capture a screenshot in Selenium?

   File srcFile = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);

2. Can Selenium be used with other testing tools?
   Yes, Selenium can be integrated with JUnit, TestNG, Cucumber, and Appium.

3. How do you handle SSL certificates in Selenium?
   Use desired capabilities to accept insecure certificates.

   DesiredCapabilities capabilities = new DesiredCapabilities(); capabilities.setAcceptInsecureCerts(true);

4. What should you do if an element is not clickable?

• Scroll to the element using JavaScript.
• Use explicit waits.

1. How do you handle stale element exceptions?
   Refresh the element using findElement() or retry the action.

2. What is the cause of a NoSuchElementException?
   The locator used does not match any element in the DOM.

3. How do you handle timeouts in Selenium?
   Use appropriate waits like WebDriverWait or increase the default timeout.

4. What is the cause of an ElementNotVisibleException?
   The element is present in the DOM but not visible on the UI.

5. How do you optimize Selenium test scripts?

• Use Page Object Model.
• Minimize hard-coded waits.
• Use reusable utility methods.

1. How do you handle CAPTCHA in Selenium?
   Use manual intervention or external tools like OCR.

2. How do you validate text on a webpage using Selenium?

   String text = driver.findElement(By.id("elementId")).getText();

3. What is headless testing in Selenium?
   Running tests without a UI (e.g., using Chrome Headless or PhantomJS).

4. How do you verify broken links using Selenium?
   Use HTTP client libraries like HttpURLConnection to check response codes.

5. What is the difference between Selenium 3 and Selenium 4?
   Selenium 4 introduces W3C compliance, better debugging tools, and native support for Chrome DevTools Protocol.

6. How do you simulate a double-click in Selenium?

   Actions actions = new Actions(driver); actions.doubleClick(element).perform();

7. How do you handle dropdowns in Selenium?

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

8. How do you perform drag-and-drop actions in Selenium?

   actions.dragAndDrop(sourceElement, targetElement).perform();

9. What are some common exceptions in Selenium?

• NoSuchElementException
• TimeoutException
• StaleElementReferenceException

1. How do you handle file uploads in Selenium?

driver.findElement(By.id("uploadId")).sendKeys("filePath");

1. How do you execute JavaScript in Selenium?

   JavascriptExecutor js = (JavascriptExecutor) driver; js.executeScript("window.scrollBy(0,1000)");

2. How do you verify tooltips in Selenium?
   Retrieve the title attribute of the element.

3. How do you manage cookies in Selenium?

   driver.manage().getCookies(); driver.manage().addCookie(new Cookie("key", "value"));

4. How do you close a browser in Selenium?

• driver.close(): Closes the current browser window.
• driver.quit(): Closes all browser windows.

1. What is a shadow DOM, and how do you handle it in Selenium?
   A shadow DOM encapsulates part of the DOM. Use JavaScript executors to access shadow DOM elements.

2. What is an AutoIT tool?
   AutoIT is a third-party tool used to handle file upload/download dialogs.

3. How do you test responsive web designs using Selenium?
   Use browser developer tools or resize the window programmatically.

4. What are WebDriverWait and ExpectedConditions?
   WebDriverWait waits for a specific condition defined in ExpectedConditions.

5. How do you integrate Selenium tests with a CI/CD pipeline?

• Configure Jenkins or GitHub Actions.
• Add Selenium tests as a stage in the pipeline configuration.