Visual testing and visual regression testing are essential techniques in the software development and quality assurance process, ensuring that applications not only function correctly but also look perfect. At its core, visual testing involves the assessment of an application’s user interface (UI) to ensure that it appears as intended across various devices and screen resolutions. It’s akin to proofreading a book for formatting and layout discrepancies. On the other hand, visual regression testing is a more specialized form of visual testing. This technique focuses on identifying unintended visual changes by comparing current UI snapshots with previously accepted baseline images.
Whenever a change in the codebase is made, visual regression testing can pinpoint if these changes have inadvertently affected the application’s appearance, thus ensuring that any modifications don’t degrade the visual experience for users. In this blog, we will explore the distinctions between both testing approaches in greater detail. So, without further ado, let’s begin…
Key Differences Between Visual Testing And Visual Regression Testing
Visual testing and visual regression testing are two different testing ways to ensure that the graphical user interface (GUI) of a web application or software remains consistent and visually appealing across different versions or environments. Here are the key differences between them:
Scope Of Visual Testing: Visual testing is a quality assurance technique that focuses on the examination of individual elements and pages within a software application. In this approach, testers meticulously inspect the visual aspects of user interfaces, such as buttons, images, text, and layout, to ensure they meet design specifications and maintain a consistent appearance. It is particularly useful for catching cosmetic defects that might affect the user experience but not necessarily the functionality of the application.
Scope Of Visual Regression Testing (VRT): Visual Regression Testing is a specialized form of testing that is primarily concerned with detecting visual differences or changes across the entire application. Unlike traditional functional testing, VRT is not focused on verifying specific functionalities or features. Instead, it captures screenshots or images of the application at different stages of development or after each release and compares them to a baseline or reference image. Any discrepancies, even minor ones, are flagged as potential regressions, indicating unintended visual alterations that may have occurred due to code changes or updates.
VRT helps ensure that the application’s appearance remains consistent and that no unexpected visual glitches or defects have been introduced as the software evolves. It plays a crucial role in maintaining a polished and professional user interface, which is vital for user satisfaction and branding.
Automation In Visual Testing: Visual testing can be executed using both manual and automated methods. Manual visual testing involves human testers meticulously inspecting the graphical user interface (GUI) of a software application to identify visual defects or discrepancies. On the other hand, automated visual testing employs specialized tools and scripts to capture screenshots or record the visual state of the application. These tools can then compare these images against expected baseline images to detect any visual differences automatically. It helps ensure that the application’s visual elements remain consistent across different platforms, browsers, and devices.
Automation In Visual Regression Testing (VRT): VRT is primarily an automated testing approach. It relies on automated tools and scripts to capture screenshots or record the visual state of an application at various stages of development or after each code change. These captured images are then automatically compared to a baseline or reference image to identify any visual discrepancies or regressions. VRT tools excel at quickly detecting even subtle visual changes that might go unnoticed in manual testing. This automation is crucial because modern software development often involves frequent updates and code changes, making it challenging to manually track visual consistency across the entire application.
Baseline For Visual Testing: In the context of visual testing, the baseline serves as a reference point for assessing the appearance and design of a digital product, such as a website or application. This baseline is typically presented as a mock-up, wireframe, or design file, and it essentially represents what the final product is intended to look like. It serves as a blueprint that helps maintain consistency in the visual aspects of the product throughout its development.
Baseline For Visual Regression Testing: Visual regression testing, on the other hand, involves comparing the current state of a web page or a component with a known correct version to detect any unintended visual changes or regressions. In this context, the baseline is a screenshot or an image capture of the existing, correctly functioning version of the web page or component. This initial screenshot serves as the baseline against which subsequent tests are compared.
Frequency Of Visual Testing: Visual testing is typically conducted less frequently compared to visual regression testing. It is commonly carried out during specific phases of the development process, especially during the initial development phase when designers and developers are working on creating the visual design of a product. It may also be conducted when significant visual changes or updates are planned for an existing application or website. Visual testing serves as a checkpoint to ensure that the visual design aligns with the intended specifications.
Frequency Of Visual Regression Testing: Visual regression testing is performed with a higher frequency and is often integrated into the continuous integration (CI) pipeline of a software development project. This means that visual regression tests are run automatically and systematically as part of the development and deployment process. They are executed each time new code changes are introduced, whether it’s through regular updates or continuous integration processes. The goal is to catch visual regressions as soon as they occur, allowing developers to identify and address them promptly.
Dependencies In Visual Testing: The effectiveness of visual testing is often heavily reliant on the skill and expertise of the tester performing the evaluation. Testers need to possess a keen eye for design details and an understanding of the intended visual specifications. Their ability to accurately identify visual issues, such as discrepancies in color, layout, or element positioning, plays a critical role in the success of visual testing.
However, the level of precision in visual testing can also be enhanced through the use of automation tools designed for capturing and comparing visual elements. These tools can help reduce human error and subjectivity, but they still require proper configuration and maintenance to ensure reliable results. In essence, the quality of visual testing can vary based on the skill and experience of the tester and the effectiveness of the chosen tools.
Dependencies In Visual Regression Testing: Visual regression testing places a heavier reliance on the quality of the baseline images used for comparison and the precision of the testing tools. The baseline images, which represent the known correct visual state of the application or webpage, must accurately reflect the desired design and functionality. Any inaccuracies or discrepancies in these baseline images can lead to false-positive or false-negative results during testing. Additionally, the precision and reliability of the tool used for capturing and comparing screenshots are crucial. These tools need to be capable of detecting even subtle visual changes and providing accurate reports.
Benefits Of Visual Testing
Visual testing offers several benefits to software development and quality assurance processes, as it focuses on the graphical user interface (GUI) of an application. Here are some of the key benefits of visual testing:
Easy To Use: The straightforward nature of visual testing makes it simple to comprehend and carry out, offering a user-centric method for testing.
Detects UI Issues: This form of testing is proficient at uncovering flaws associated with user interface design and functionality, such as misaligned elements, improper color contrast, and layout problems.
Time-Efficient: Automating the tasks of visual testing allows testers to allocate their time to different kinds of evaluations.
Enhances User Experience: By making certain that the application appears and operates as anticipated, visual testing contributes to a better overall user experience.
Challenges Of Visual Testing
While visual testing offers several benefits, it also comes with its share of challenges and complexities. Some of the common challenges associated with visual testing include:
Limited Scope: Visual testing focuses primarily on assessing the graphical user interface (GUI), leaving potential functional or non-GUI issues undetected.
Needs Expertise: Performing visual tests demands a specific skill set, including a deep understanding of design elements and visual principles.
Not Applicable For All Software: Some applications with either no GUI or a minimalistic graphical interface may not be ideal candidates for visual testing.
Benefits Of Visual Regression Testing
There are several benefits of incorporating visual regression testing into your software development and testing processes. Here is the list of a few main ones:
Ensures Consistency: It helps maintain a consistent and polished user interface across different browsers, devices, and screen sizes. This is critical for delivering a seamless user experience.
Prevents Visual Regressions: By comparing each new version of your application with a baseline image, visual regression testing helps prevent visual regressions from reaching production. This leads to higher product quality and reduces the risk of embarrassing visual defects.
Facilitates Collaboration: Visual regression testing provides a clear visual representation of any changes, making it easier for developers, designers, and testers to collaborate and pinpoint the cause of issues.
Challenges Of Visual Regression Testing
Here are some common complexities associated with visual regression testing:
False Positives And Negatives: Automated visual regression testing tools may sometimes report false positives (indicating issues that aren’t real problems) or false negatives (failing to detect actual issues). This can lead to wasted time investigating non-issues or missing real problems.
Dynamic Content: Web applications often have dynamic content, such as user-generated data, ads, or live feeds, which can make it challenging to create stable baseline images for comparison.
Localization And Internationalization: Testing across multiple languages and locales can be demanding, as it requires creating and managing baseline images for each language.
Both visual testing and visual regression testing are crucial components of a comprehensive quality assurance strategy. While visual testing addresses the immediate visual aspects of your application, visual regression testing goes a step further, safeguarding your project’s visual consistency throughout its lifecycle. One tool that has gained popularity for simplifying these testing processes is LambdaTest. LambdaTest, an AI test orchestration and execution platform, offers a cloud-based platform that allows developers and testers to perform visual testing and visual regression testing effortlessly across a 3000+ test environments including real device cloud. Its capabilities, including screenshot comparison and test automation, enable teams to streamline their testing workflows and deliver polished, visually consistent applications to their users.
By understanding the differences between these testing methods and leveraging tools like LambdaTest, you can enhance the quality and reliability of your web applications, ensuring a stellar user experience every time.