April 10, 2024
The Ultimate Guide to Understanding Visual Regression Testing

Today, users rate the quality of the software application based on their behavior and visual appearance. This is because the maximum users of the software application are not technically sound. Therefore, we must develop a software application that functions well to grab a position in the software industry. We need to focus on its appearance. For this, the best thing a developer or tester may do is to perform visual testing

Also, the other objective of the developers while developing a software application is to make it in the long run. This requires frequent maintenance and updation of the software application. Updation is done through code change. A slight change may also lead to the malfunctioning of the software application. Furthermore, to overcome these issues, we can perform visual regression testing.

In visual regression testing, screenshots are captured before and after test execution to compare them. Comparing screenshots helps the developers and testers find any visual discrepancies present in the software application. In this article, we will briefly learn about visual regression testing. How is it implemented? What are the advantages and disadvantages of using visual regression testing? And then, we will get to know about the best practices. So, let’s get started. 

Understanding Visual Regression Testing

Visual regression testing confirms that a software application looks and behaves as anticipated. There are no unintended changes to its appearance or usefulness. This process compares the base form of your software application with the current form and checks for visual contrasts.

Visual regression testing includes capturing pictures of your software application or website and utilizing specialized apparatuses to compare them and highlight contrasts. There may be contrasts between the two forms that demonstrate changes to the appearance or format of the application or bugs or issues that must be fixed.

They are mostly utilized in conjunction with other types of testing, such as functional and usability testing. It is used to ensure that a software application functions properly and meets quality benchmarks. It is usually valuable if the appearance of your software application is critical to client involvement or if there are frequent changes that must be closely observed.

How Visual Regression Testing Works:

We now know that visual regression testing is done to find visual differences in the software application. The screenshot is taken before and after the execution of the test cases and is compared. Here, we are breaking down this implementation for a clear understanding.

  • Baseline Creation: A baseline is set for initializing the visual regression testing process. This baseline represents the expected appearance of the software application at the user interface. Furthermore, this baseline is set as a reference for future comparison. The baseline must be created carefully and then validated. Having a clear vision of how your software application appears at the user interface is important. 
  • Automated Comparison: The next step is to execute the test cases once the baseline is set. During the execution, the test automation tools capture screenshots of the software application. This shows how the software application currently appears in the user interface. Then, these screenshots are compared using the automated tools for visual regression testing. 
  • Detection of Differences: During the comparison, the differences are detected. The difference can be present in the structure or layout. The automated tools even detect the pixel difference present in the software application. 
  • Reporting: Once the comparison is done and differences are found. A detailed report is generated. These reports contain descriptions of the differences. Also, it has their location. The location helps in easy tracking of the issue. The description helps in an easy understanding of the issue. A report also helps review the software application in the future during updation and maintenance. 
  • Integration with CI/CD Pipeline: The software application needs to be tested after every update. Setting up the environment for testing after every slight change can be effort-taking. Therefore, it is suggested to integrate the visual regression testing into a CI/CD pipeline. Here, whenever a code update is done, the test cases will automatically be executed, and the software application will be verified and validated. 

Key Components of Visual Regression Testing

There are several components of visual regression testing. These are essential for conducting successful testing and developing a seamless software application. The key components are mentioned below.

  • The most important component is the screenshot capturing. You require a screenshot to detect the visual difference present in the software application.
  • Another important component is a baseline. We need to create a baseline to conduct visual regression testing. We need to have a reference point for comparing the screenshots.
  • To ease up the process of visual regression testing, we require automated tools that can detect the differences between the user interface and the baseline. 
  • Differential analysis is another key component of visual regression testing. It lets you identify whether the detected issue is genuine or a false positive.
  • Test reports are another essential component of visual regression testing. It helps in pointing out the location of visual differences. Also, the information about the issue helps analyze the actual problem and solve it efficiently. 

Tools for Visual Regression Testing

Several tools capable of performing visual regression testing are present in the market. Choosing one could be a problematic situation. Therefore, here is a list of highly preferred tools used in the current industry environment. 

  • Selenium: Selenium is an open-source tool various testers use for visual regression testing. It allows you to conduct cross-browser compatibility across multiple devices and environments. Also, it allows you to record, edit, and debug the test simultaneously. Selenium can be used with any programming language. 
  • Chromatic: It is best suggested for testing web applications. It allows you to test across multiple desktop and mobile browsers. Also, it gives you the authority to conduct parallel testing to ensure seamless testing of the software application in less time. Chromatic tests every software application component individually rather than all at once. 
  • Endtest: Endtest comes with intelligent test automation that allows you to conduct efficient end-to-end testing for the software application. Also, it has a screenshot visual layout testing option for conducting visual regression testing. It is reliable and secure, providing a seamless user experience and quality software application. 

Benefits of Visual Regression Testing

Testers and developers highly prefer visual regression testing due to its following benefits.

  • It allows early detection of bugs, later saving software applications from other complex issues.
  • It makes your software application consistent across every version and device.
  • It helps enhance the end-user experience.
  • It reduces overall time and effort when integrated with an automated tool.
  • It helps in developing a quality and confident software application. 
  • To confirm an excellent user interface we require feedback from real users. Here, the visual regression testing is beneficial for enhancing collaboration among various stakeholders of the software application.

Challenges and Limitations of Visual Regression Testing

There are several challenges and limitations of visual regression testing. Knowing them in advance will allow you to take extra care while executing your test cases. It will save you from complex and critical problems in the future. 

  • Testing a dynamic software application can be challenging. You must pay extra attention while testing dynamic elements such as ads or animations. 
  • Automated visual regression testing can sometimes provide a false alert by pointing to insignificant differences. And you need to investigate that unnecessarily. 
  • Regression testing requires an accurate and well-designed baseline image. This takes a lot of effort and time. Changing it with frequent user interface updates can increase overhead costs and time. 
  • Automated visual regression testing may give false positives. Furthermore, determining and ensuring its genuineness is challenging. 
  • We need to test our software application across every device and browser to ensure no visual difference is present. This increases the complexity of testing the software application.

Best Practices for Visual Regression Testing

One faces various challenges while testing the software application using visual regression testing. At the same time, one can follow certain best practices to overcome them. Here is a list of them. 

  • Creating a baseline for comparing your screenshot is essential. You should establish a clear objective for your software application interface. Design your baseline cautiously so that major alteration is not required in the future. 
  • You must integrate your visual testing into the CI/CD pipeline. This will continuously test your software application on every change made. Furthermore, it allows early detection of bugs and debugging them.
  • You should use a version control. This will help you in logging the changes made to the software application. Also will help in easy collaboration among the team members. Furthermore, you can even backtrack to a previous version if needed. 
  • You should avoid conducting visual regression testing on the entire software application. Rather, you should only select critical UI components and elements that provide visual effects to your software application. 
  • Testing for cross-browser compatibility adds complexity to your software testing. However, using cloud-based platforms like LambdaTest eases up your testing process. Here, you do not need physical devices for testing your software application, saving the resource setup cost. Also, it gives you access to a wide range of devices and versions.

LambdaTest is an AI-powered test orchestration and execution platform to run manual and automated tests at scale. The platform allows you to perform both real-time and automation testing across 3000+ environments and real mobile devices. 


We have almost the entire globe using one or more software applications. With limited technology knowledge, the visual appearance of the software application has been set as a standard for declaring the success of the software application. Therefore, focusing on visual testing has become a pivotal part of software development. The article above mentions a brief knowledge about visual regression testing that a tester or developer should know. This will help them perform seamless software testing and provide an excellent user experience. 

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