Visual Regression Testing: Detecting UI Changes With Precision

Visual testing is a way to verify the authenticity of a program according to its design, appearance, and behavior. It assists in identifying any unintentional changes to visual presentation or performance. The process involves comparing the initial version of the app (or website) (referred to by its base) against the current version to determine any visual differences that could be present.

Today’s software industry is undergoing intense competition to release new software with many options and features.

To stay ahead of the pack, the latest software programs are launched frequently, so updates are regularly made by altering the current lines of code. But even a small modification to the code could affect the performance and functionality of the code in place, which could impact users’ experience.

In the fast-paced digital world, the user experience is crucial, and visually flawless UI for software applications is essential. Additionally, appealing layouts and designs with various colors, fonts, and other visual elements are essential for user satisfaction.

According to research, 88% of people are less likely to visit the site after a negative experience. Additionally, Stanford research states that 90% of users believe that the design of a website affects the first impression a website gets from visitors.

Sometimes, we’ll not use certain eCommerce websites or applications when their user interfaces are not as good as they should be. It could result in businesses losing business transactions.

To ensure that the user interface is visually pleasing and user-friendly, we have to carry out an additional layer of testing known as visual regression testing. This type of test tests the elements’ visual layout and appearance and ensures that they align with design specifications and deliver an enjoyable user experience. So, let us understand visual regression testing in detail.

What Is Visual Regression Testing?


Visual regression testing, sometimes known as visual testing for UI, is a test method to test the visual appearances, user interfaces of graphical user interfaces, and software performance.

Visual regression testing allows you to examine the appearance of software applications and identify any obvious bugs on the pages that appear on websites or mobile applications. After that, a comparison is conducted between the output visible in software programs and the anticipated result of the design.

What is the purpose of visual regression testing? Are you merely looking at the design of the software application? Visual regression testing checks every aspect of websites to verify the proper shapes, sizes, and locations across all devices, browsers, and operating systems.

Furthermore, visual regression tests confirm the diverse behaviors of websites, including elements like labels and buttons, navigation content, and many other functions.

This allows software developers to create the same experience for their customers. They can easily identify mistakes or discrepancies in the appearance of websites or web applications by looking at the expected and rendered output.

To learn more about visual regression testing, Click here.

Can Functional Testing Address Visual Issues or UI Changes?

It is important to understand that testing for functional functionality within software applications can determine how well the UI performs. For instance, while using eCommerce software, when a customer presses “Pay Now,” the functional test will ensure that the link can deduct charges from the user’s account correctly. However, verifying the specifics, like aligning the “Pay Now” button through functional tests, requires much effort.

Functional tests may overlook the following aspects:

  • Minute pixel differences
  • Alignment shifts
  • Page layout discrepancies
  • Rendering issues
  • Element overlap problems
  • Responsive layout variations
  • Font discrepancies
  • Color variations

Confirming these points using functional tests could lead to chaining lengthy assertions to record the visual differences between versions. Ultimately, the scripts become an insecure break, are broken, and are difficult to maintain in the next releases.

These issues are solvable by the implementation of the automated testing of visuals. Visual tests are primarily focused on testing the visual aspects of an application. They offer an extensive evaluation of its design, appearance layout, and design, assuring an unmatched user experience with visuals.

Remembering that an operational test alone does not assure the non-existence of visible bugs is crucial. Visual regression testing is required within the Software Testing Life Cycle to test the software’s applications visually.

Visual Vs. Functional Testing: Know the Difference


Visual testing concentrates on the design and appearance that the interface displays; however, Functional testing concentrates on testing the capabilities of the software. Functional testing doesn’t capture visual issues like alignment, pixel-to-pixel comparison rendering, layout overlap, font modifications, or responsive design issues.

Most software tests are designed to test the various components of the software work according to their intended purpose. But, these tests usually ignore the vital visual aspect from the user from the user’s perspective.

In the example at the start of this guide, the functional tests would have revealed an operating website with the check-out feature included. However, the users encountered a significant issue and could not complete one of the main features.

Different Types Of Visual Regression Testing

Different approaches to testing, like tests that test for regression, can help ensure that updates to the software aren’t causing unexpected problems concerning its visual aspects. Regression testing is the contrast between a web page’s look before and after an update to ensure the overall look and feel are consistent.

Many specialized testing subtypes can be tailored to meet the requirements of a particular project within these three categories. We will now be able to understand the kinds of tests.

Usability Testing: This category of visual tests is designed to assess the ease of use and design. Experts in the area of user experience use techniques like eye-tracking to measure the ease the user can navigate an interface or design.

For instance, a usability test might involve assessing how people interact using the menu bar on the mobile application or the speed at which they find items on the eCommerce website.

A/B Testing: A/B testing enables designers to test two designs to determine which is most effective in communicating an exact message or satisfying the needs. For example, a website designer could examine two different color options to determine which produces an attractive call to action.

Compatibility Testing: This form of visual UI testing is designed to ensure that the software works as it should across different browsers, platforms, and devices. Examples include testing the look of a site’s design on different platforms or testing the performance of mobile apps using simultaneously Android or iOS devices.

Color contrast testing: This visual test tests how much contrast is present between different colors to ensure they are suitable for a specific intended group or message. For example, it confirms whether the brightness between the background color and text is within a suitable range.

Responsive Testing: This test will ensure a website’s functionality and visual appeal across different devices like laptops, desktops, tablets, and many more.

Motion graphic Testing: This test evaluates the effectiveness with which the design communicates using motion graphics, like videos and animations, to improve the quality of services, products, or messages in a captivating way.

Iconography Testing: This study examines the importance of icons and other graphic elements in a website or web application for communicating the intended message or action to the end-users.

Visual Accessibility Testing: This kind of test does not just ensure accessibility to assistive technology and checks for visual accessibility to everyone. For instance, an accessibility professional may determine whether users can easily discern similar-colored buttons on websites.

Layout Testing: Layout testing concentrates on the layout of elements within a layout to ensure uniformity and aesthetic appeal to the interface.

Visual Regression Testing: Where and When Not to Use?


Automated visual tests examine the software’s visual aspects and compare the results with standard screenshots to confirm their alignment. This method also examines aspects associated with visual aesthetics, such as consistent rendering, exact alignment, and the correct dimensions.

It’s important to remember that this technique is unsuitable for situations where time limitations are an issue. Visual regression testing takes enormous time and should only be used in situations with tight deadlines. It’s not the ideal choice to be used purely in manual or automated execution.

A combination of manual and automated regression testing usually yields the best results. It is not advisable to rely solely on the accuracy rates produced by tools in the process of comparing images.

The visual regression test is among the most reliable ways to attain the desired results. It is conducted alongside functional testing to test the visual integrity of an application. It can be challenging to resolve since functional automation frameworks are built to handle functional issues.

Various Visual Regression Testing Tools For Detecting UI Changes

To facilitate visual testing, there is always a requirement for various automated tests, which help identify the problem and help ensure that their solutions are in place. As mentioned earlier, the process of automation of the visual test does not only mean making it easier to test and save time.

If you are performing the test visually and require an application to write and conduct the test. It will require developers and QA to create codes that can quickly replicate the actions of users. In this case, every test includes statements describing conditions that can be passed or failed.

To deal with this test, you need to organize them into blocks of different sizes and place them into separate files, which are utilized to test a specific module or function of the software.

After finishing your test, you’ll require visual test tools to communicate with browsers. They are not just for visual tests, but they also allow you to produce images of websites. We would like to know more about what you think about this tool:

#1 LambdaTest:

LambdaTest is an AI-powered test orchestration and execution system that provides instant visual testing and transforms the identification of visual UI bug regressions. It offers an AI-powered SmartUI platform that allows for visual regression tests at a size.

With LambdaTest, the ability to perform intelligent image-to-image comparisons is a breeze, making it possible to detect visually distinct differences between different elements, such as layout, text colors, sizes, padding, and placement.

What distinguishes LambdaTest is the capacity to create automated visual tests with different testing frameworks such as Selenium, Cypress, Playwright ,Storybook, and Appium with a range of programming languages, such as Java, Node.js, and C#.

Additionally, LambdaTest’s parallel testing capabilities dramatically cut down on the time it takes to test, and its seamless integration of other tools for CI/CD makes it an outstanding choice for creating flawless software with excellent visual quality.

#2 Selenium:

Selenium is an extremely powerful open-source automation test tool created for web applications. It makes automated visual testing easier by enabling you to record screenshots of web pages when testing. This feature lets you test your interface’s elements, the layout, and layouts of the pages visually.

With Selenium, it is possible to connect to web-based elements and navigate websites through webDriver. WebDriver API. A unique feature of Selenium is its compatibility with various web browsers, making it flexible to conduct visual tests on various platforms.

#3 Cypress:

Cypress is an open-source automation software that offers valuable visual records throughout the process of testing. The logs can help you track the progress of your test and spot any flaws easily. Cypress allows real-time testing by simulating user actions and interactions within the web browser.

Its unique capacity to hold off until elements are displayed and then become interactive increases the validity of visual tests. It also gives access to network-based requests and XMLHttpRequest (XHR), allowing users to simulate and intercept responses. Additionally, you can extend your Cypress visual regression testing using plugins like “cypress-image-snapshot.”

Steps to Perform Visual Regression Testing


Visual UI testing involves various stages and steps that require attention to detail. We will discuss them in greater detail:

1) Choosing the right visual test tool: When performing a visual test first, you need to select the best visual test instrument. You’ve now discovered the different visual test tools; it can be difficult for some people to select the best tool for software. It is important to research various tests using visuals, study their capabilities, and then evaluate whether they are compatible with your specifications.

2) Creating a robust test plan: If you’re using an appropriate visual test instrument and can use it, you must create the test plan, including all details regarding the test. This information can be found as follows:

It is important to clearly identify what component of the software program you’ll be evaluating visually. It could include important web pages, crucial user flows, and different screen sizes.

The testing plan should include information on the different devices, browsers, and resolutions you wish to test in your methods. It is crucial to remember that the test plan should be prioritized according to the target group of users.

It is necessary to create an initial baseline by taking a screenshot of the application’s interface to use as a reference point to compare to the visual test results.

3) Set up your Testing Environment: The most important element to perform visually-based regression testing is establishing your setting up the testing space. It is possible to think about the following elements:

  • Start by selecting the devices, tools, and browsers that are similar to those end-users utilize. Additionally, ensure that their configurations are similar to the configurations of the real-world environment. It is crucial to ensure that test results are precise and correspond to real-world user experiences.
  • If your testing process allows automation, setting it to capture seamless screenshots is vital. This configuration should seamlessly integrate with your ongoing integration (CI) pipeline, allowing automated visual checks to be integral to the development process.
  • To avoid the possibility of false positives resulting from data changes, it is essential to ensure consistency of the test data across environments for testing. This will ensure that any differences in the visual appearance are due to code changes instead of data discrepancies.

After the above steps have been followed, you need to implement by following the necessary steps:

Step 1: Identifying UI elements and choosing the best testing approach

Start by identifying the UI elements that need to be tested. You can choose between manual or automatic testing. Manual testing involves looking over every UI page, while automated testing uses algorithms to evaluate visual elements against a reference.

Step 2: Ensure a balance between automated and manual testing

Check if your software requires detailed manual testing to verify attributes such as colors, fonts, or animations. Although automated tests are more accurate and faster, combining both strategies may be needed. No matter the chosen method, the aim is to ensure uniform UI functions across different devices and platforms.

Step 3: Ensuring Cross-Platform Compatibility

Once you have identified the components to test, ensure their accuracy in representation and support for a variety of devices and browsers. Testing across platforms is possible with tools such as pixel-to-pixel comparators or software for screenshot comparison, making it simpler to test the different versions against the baseline.

Step 4: Leverage Automated Visual testing tools

Visual test tools that are automated are essential in identifying any deviation from the design and producing specific reports about these deviations. The goal is to verify the exactness of the design and the operational efficiency of all design elements regardless of the device or browser being utilized.

Step 5: Integrate Development Workflow through Automated Testing

Integrate automated testing into your process of development. This will save time and money by identifying issues before their impact on the launch or production process and ensure every user’s identical appearance of the software’s User Interface (UI). The ability to identify issues before production is extremely valuable.

Step 6: Implement UI Change Monitoring

Set up a monitoring system that can quickly and accurately identify UI changes. This proactive approach quickly eliminates problems while ensuring that the UI of your application is continual quality and uniformity.



Visual regression testing is a test software method that validates the layout and visual design of an interface for users or a graphical component within the software application. Its importance in the field of web development cannot be understated as it provides a pleasing appearance and optimum functionality.

This comprehensive guide explains all aspects of tests using visuals, such as categories, benefits, and tools that are accessible. This guide will give you an in-depth understanding of the basic concepts and provide a solid foundation for detecting UI changes. Through practice, you’ll quickly become an adept visual tester.