How To Debug Selenium Scripts For More Effective Testing?

As software testing becomes increasingly complex, automation plays a vital role in ensuring the reliability of software products. Selenium is a popular open-source automation framework for testing web applications. However, like any technology, Selenium testing can be prone to bugs, which can cause headaches for automation testers. Debugging Selenium scripts is an essential part of the automation testing process, as identifying and resolving issues early on can save valuable time and resources. Effective debugging requires a systematic approach, attention to detail, and a deeper understanding of Selenium’s features and functionalities. 

In this article, different ways to debug Selenium script will be discussed to improve software testing and ensure the quality of the web application. 

What is Debugging?

Developing and maintaining test automation code is not an easy task. Despite thorough planning and execution, unpredictable outcomes may arise in automated test cases, resulting in false positives or negatives. In such situations, debugging is essential to pinpoint and rectify issues.

Debugging is a crucial aspect of software development that involves detecting and resolving errors or bugs in the software application. This process plays an integral role in ensuring the seamless functioning of a software application and attaining its intended performance. Debugging necessitates careful inspection and analysis of code, followed by identifying the underlying issue and then making appropriate modifications to rectify the problem.

Debugging Selenium scripts involves identifying and resolving code issues that prevent the script from running accurately. To debug the error, you must have a combination of advanced analytical and problem-solving abilities alongside a comprehensive knowledge of programming languages and software development methodologies. Thus, debugging Selenium test scripts is an ongoing process that requires constant effort and attention to detail and is a crucial aspect of ensuring that software products are of high quality and meet user expectations.

Let’s get started. 

Techniques Of Debugging Test Automation Scripts

In automated testing, the quantity of test cases cannot ensure seamless execution. Changes in an application’s user interface or business logic can disrupt Selenium-based test scripts. It is common for test scripts to fail not because of a flawed code in the automation framework but due to a bug in the application itself. To identify the root cause of test case failure, it is essential to employ assertions properly before proceeding to advanced debugging techniques.

When you perform the Selenium test, it happens that issues like element not found or timeout errors and others may encounter. This prevents the test script from running and executing further testing. It is important to debug Selenium scripts to find the cause of errors and fix it early to ensure their execution, 

When developing a Selenium test from scratch, it is beneficial to import utilities that make it easier to debug source code. Debugging buggy code using the Java console output alone can be challenging in failure cases. 

To effectively address these challenges, let us explore debugging techniques that can simplify the development process for professionals.

Local testing

One effective method of validating your script is by conducting local testing on your local machine. In circumstances where automated testing is executed on remote devices or cloud platforms may be difficult. The approach of visual validation and manual intervention may provide insight into potential issues that the automation test may miss. 

The script must run in a consistent local testing environment with the remote device to evade errors from discrepancies in configuration. When debugging your test script with local testing, it is crucial to take note of this aspect.

Capturing Screenshots

To identify the precise location and cause of a failed test case, it may be necessary to devote a substantial amount of time to observe. However, it is unreasonable to expect testers to maintain an intense focus for extended periods of time. To mitigate this issue, it is recommended to capture frequent screenshots.

Having a screenshot of the point where your test case failed can significantly simplify the debugging and troubleshooting process. Fortunately, Selenium offers a “TakesScreenshot” interface designed specifically for capturing web page screenshots. By utilizing this interface, you can effortlessly obtain the necessary screenshots to resolve any issues encountered during testing.

One such cloud-based platform is LambdaTest which offers cross-browser automation tests. The easiest way to capture screenshots in Selenium is using the cloud Selenium Grid which helps to automate tests across 3000+ browsers, devices, and OS. 

Session Recording

Session recording is an advanced debugging method. When running a lengthy regression suite, it can be challenging to monitor the entire execution of consistently failing test cases. To address this issue, enabling session recording and retaining it for future debugging purposes can be extremely helpful. In cases where test cases in the regression suite fail to replicate when executed as a single class, session recordings provide an effective solution. This approach allows us to observe and verify the test actions effortlessly, ensuring no unexpected alerts or elements appear.

Session recording provides a superior debugging level compared to basic logs or screenshot capturing. It is especially beneficial for test suites that contain a large number of test cases. With session recording, developers can gain valuable insight into server performance and UI usability. Additionally, recorded sessions can be easily shared with developers to help replicate any bugs found in the production or staging environment.

Add Breakpoints

Breakpoints are a fundamental component of an integrated development environment (IDE) that enable developers to temporarily halt the execution of code at different stages of their test cases. By strategically placing breakpoints at different stages of the test cases, developers can detect and rectify errors efficiently. This approach allows them to extract critical data elements from the source code during the pause in execution.

Debugging code with the use of breakpoints can be accomplished efficiently by following these steps:

  • Set up breakpoints at the points where issues have been identified in the code.
  • Initiate the source code in debug mode.
  • Verify the data retrieved in the debugger.
  • Continue debugging if additional breakpoints are incorporated.
  • Halt the debug mode execution.
  • Fix the error and deploy the updated code.

Debug Selenium-Based Test Scripts on an Opened Browser

When the final steps of a selenium test case fail, debugging them within an already-opened browser is advantageous. This approach saves valuable time as executing the test again would require the observer to sit and monitor the code. Debugging the test code in an already-opened browser involves certain manual tasks, such as initiating the browser and performing web actions to verify if it aligns smoothly with the test scripts.

Chrome Devtools Protocol is a powerful tool used for inspecting and debugging Chrome browsers. By utilizing this tool, you can efficiently debug code that may contain errors. Ultimately, this approach saves both time and effort while improving the overall quality of the code.

Recheck the Environment

If your Selenium test cases encounter errors or technical issues, it is important to ensure that the correct environment is properly set up. This includes installing the latest and correct version of the required browser and other necessary software components such as the latest version of JDK/JRE, Selenium WebDriver specific to your operating system, and an IDE like Eclipse or IntelliJ for writing test scripts. 

Once all the necessary components are installed, setting up environment variables for your operating system to allow Selenium WebDriver to be accessed from anywhere is important. By taking these steps, you can ensure that your Selenium tests run smoothly and effectively.

Simplify the Test Case

If you encounter difficulty in executing your test cases, it is possible that the code syntax is overly complex. Streamlining the test case is imperative to ensure that your code runs smoothly.

To simplify a test case, consider the following steps:

  • Break down the code into smaller, more manageable fragments that are easier to comprehend.
  • Carefully examine each step of the test case to pinpoint and understand its expected behavior.
  • Utilize automated testing tools and implement assertions to validate the desired behavior.
  • Automate the test cases and use Selenium API to interact with the browser for streamlined execution.

The benefits of Selenium can be leveraged by using LambdaTest, where you can run tests on a Selenium Grid with thousands of parallel sessions, ensuring faster test execution and quicker feedback.

Check Timing Issues

Your test cases may encounter timing issues, which can be attributed to various factors. This includes instances such as slow responsiveness of the testing environment or slow execution of the test cases. To mitigate this issue, it is advised to ensure that the page is fully loaded before executing the test cases. Additionally, increasing the wait time for elements to load and utilizing explicit waits when feasible can also be helpful.

Effective synchronization techniques can be employed to determine the presence of an element, while the JavaScript executor can handle AJAX calls. It is recommended to utilize appropriate locator strategies and element visibility techniques to identify the desired aspect promptly.

Use Assertions

Assertions are crucial in debugging Selenium test cases due to their reliable functionality. They are essential elements in the development process of Selenium tests as they serve the critical purpose of informing developers whether an application is performing as designed. Using assertions, developers can verify whether a specific condition or test case executes. This is important, as any failure to execute a test could throw an error, requiring the automation team to resolve the issue.

To effectively utilize assertion, it is recommended to compare the outcomes of the actual test execution with the anticipated results. Identifying the discrepancies between these two results makes it easier to facilitate debugging the issue at hand.


Debugging Selenium scripts is a critical step in ensuring effective testing. With the right approach and tools, you can swiftly identify and fix any issues in your code, saving you time and resources in the long run. Remember to use session recording, logging, and breakpoints to isolate the problem and identify the root cause. By mastering the art of debugging, you will become a more efficient and effective Selenium tester, delivering high-quality results with every test.