As mobile applications continue to grow in popularity and usage, having a solid testing strategy in place is crucial for developers. Visual testing is an important technique for easily automating and streamlining tests across different devices and platforms.
This method allows for easily detecting discrepancies between actual and expected visual elements, ensuring that the application delivers a consistent user experience. To integrate visual validation into your mobile testing approach, here is an overview of what visual testing entails, along with some tips to follow.
Visual testing validates far more than simply checking the functionality of an app. It involves validating the aesthetics, UI components, visual hierarchy, responsiveness, and more. For mobile apps, this means carefully examining how the app displays across multiple device sizes and platforms.
In this article, let’s explore the process of visual testing and what are their advantages and disadvantages. you will also understand the key differences between manual and automation testing of visual testing.
What is Visual Testing?
Imagine you are buying a gift on an app. You carefully choose the gift and proceed to checkout, only to encounter an unexpected UI defect. The “Proceed to Payment” button is partially obscured, making it impossible to complete the purchase. Such glitches can ruin the digital experience and result in lost sales if customers are unable to complete purchases.
Fortunately, visual testing can catch such problems early on, allowing developers to fix them before launch. Without an army of manual testers, it can be difficult to detect these issues. Visual testing can thus prove to be a crucial tool in ensuring a seamless user experience.
Visual testing is a software testing technique that captures screenshots of the UI and compares them to a set of reference images to detect any visual differences or defects.
There are a few key reasons why thoroughly testing the visual appearance of mobile apps is so important:
- Early visual testing saves money and enhances user experience. Conducting thorough interface inspections while an application is still in development makes it easier to catch and fix visual defects.
- Visual testing confirms colors, fonts, imagery, and overlay animations appear correctly on every mobile platform. Such consistency strengthens brand recognition and integrity.
- Checking different screen sizes uncovers responsive design issues quickly – before users encounter problems like overlapping elements, odd text wrapping, or components that function poorly on smaller devices.
- Users decide if an app looks professional and trustworthy in seconds. Comprehensive visual validation enhances UX.
Why Visual Testing?
There are many reasons why visual testing is important, including:
- Visual testing confirms that the user interface (UI) matches specifications and usability principles. It helps identify the visual bugs or design inconsistencies that can affect the user experience, which might lead to user frustration or sometimes abandonment of the application.
- Visual testing allows organizations to identify UI defects that may not be apparent through traditional testing methods. Elements overlapping, misalignments, and other visual discrepancies can be detected early in the development process.
- A seamless, aesthetically pleasing interface significantly improves user experience. Visual testing ensures that users can interact with the application effortlessly improving overall satisfaction.
- Unlike manual testing or adding thorough validations to automation scripts, visual testing provides efficiency. It efficiently captures and compares visual states, offering a streamlined approach to identifying and addressing UI defects.
- With the dynamic nature of software development, changes in screen size, element selectors, or other parameters can impact the user interface. Visual testing adapts to these changes, providing a robust mechanism for ongoing quality assurance.
Steps for Performing Visual Testing on Mobile Application
The steps to conduct visual testing for mobile apps are as follows:
- Thoroughly Review Design Specifications: Examine style guides, UI/UX requirements, icons, fonts, color hex codes, spacing measurements, approved device screen resolutions, and any other applicable visual criteria in fine detail so you have an in-depth understanding of what the intended aesthetics and functionality are for the app.
- Select a testing strategy: Decide whether to utilize manual visual testing, automated visual testing, or both. Manual testing involves human testers visually inspecting the app on a variety of physical devices and screen sizes. Automated visual testing uses tools and frameworks to programmatically crawl through flows, capture screenshots, and compare them against approved baseline images using algorithms.
- Construct a Testing Environment: Set up your testing environment with the necessary mobile devices, operating systems, resolutions, testing tools, and frameworks to represent actual user conditions.
- Construct a baseline image: Generate a set of approved reference screenshots that establish the intended visual appearance for each screen in the mobile application to serve as a baseline for comparison during testing.
- Execute your test: Run UI validation test suites, either manually or by utilizing test automation tools. Document any interface defects identified for correction.
- Review Visual Testing Results: Carefully inspect test outputs and screenshots to qualify errors from false positives. Analyze the generated reports to inform optimization of test coverage
- Iterate Testing as Design Evolves: Schedule regular UI checks with each software update to maintain quality. Enforce visual standards throughout application lifecycles.
Cloud-based testing solutions like LambdaTest offer a versatile testing platform to automate
visual UI and functional testing of mobile apps across 3,000+ real desktop and mobile
environments. LambdaTest is an AI-based test orchestration and execution platform that facilitates visual testing in diverse settings.
In conclusion, When performing visual regression testing, it is important to identify the UI elements that need to be tested, determine their intended behavior, create test cases, run the tests, and examine the results. repeating the tests frequently. Following these steps can assist in assuring comprehensive testing and improving the overall quality of the mobile application.
Types of Visual Testing
There are two types of visual testing which are beneficial for mobile visual testing:
1. Manual Testing
In manual visual testing, testers carefully examine website layouts and user interface components. They manually take screenshots, comparing them against baselines to identify differences. Component explorers also facilitate manual checks, testers use these tools to isolate interface elements, define test states, and validate rendering and functionality.
When a test is conducted manually, it is supervised and carried out entirely by a human.
Experience and skills are more important in manual testing because the testers carry full responsibility for the test. Manual testing is a complex and time-consuming process that has a high potential for human error. Unlike automated testing, manual testing does not require testers to have specific programming language knowledge.
Additionally, testers are free to test any unexpected feature they come across during the testing process, even if it was not the test’s original Some tests, for example, exploratory tests, can only be carried out manually.
Advantages of Manual Testing:
- Doesn’t require programming knowledge
- Efficient in finding visual bugs
- More flexibility and freedom for the tester
2. Automate visual testing
Automated visual testing utilizes software tools to automatically validate whether a user interface visually matches its intended design. Automated visual testing is faster and more accurate than manual methods. Software tools emulate human visual perception, automatically capturing and comparing UI screenshots against baseline images. Any differences instantly get flagged, enabling the rapid detection of visual defects. This ensures the application interface matches specifications without reliance on error-prone human effort.
Because they generate easy-to-use, automatically generated reports that are available to all team members, they are also transparent and recyclable. To create automation scripts, the tester must be skilled in a few different programming languages to define expected workflows and results. After the test is complete, the actual and expected results are compared to identify any failures.
Automating regression visual testing is recommended to deal with frequent changes occurring to a stable UI. Automated visual testing is faster and more accurate than manual methods.
Advantages of Automation Visual Testing:
- Reliable, effective with minimum risk
- Fast and time-saving
- Provides better test coverage
- Test scripts can be reused when needed
Manual Visual Testing Vs. Automated Visual Testing: Key Differences
Manual Visual Testing
Automated Visual Testing
Nature of Testing
|Requires human evaluation of user interfaces
|Uses tools and scripts to capture and compare UI elements
|Relies on the subjective judgment of testers to evaluate aesthetics, user experience, and visual consistency.
|Utilizes predefined algorithms and comparison mechanisms to objectively identify visual discrepancies.
|Needs a dedicated team of testers performing manual checks.
|Optimizes resources through test automation, reducing the need for a large team.
|Simpler in terms of setup and execution, making it accessible to testers with varying levels of technical expertise.
|May require more technical expertise for tool configuration, script development, and maintenance.
|Susceptible to human oversight of subtle defects.
|Enables precise detection of even minor visual issues.
Advantages of Visual Testing
Visual testing offers several advantages that can improve the quality and user satisfaction of mobile applications. Some of the main advantages of visual testing are:
- Improving User Satisfaction: Visual testing validates that the look-and-feel and workflows align with design guidelines to deliver a quality user experience. An attractive, professional interface combined with intuitive interactions increases user adoption and retention rates.
- Detects visual defects early: visual testing allows interface defects like aesthetic issues, consistency errors, or functionality problems to be identified early in the software development life cycle. Catching such UI bugs in initial development phases costs considerably less to fix compared to later phases like system testing or after going live.
- Supporting Continuous Integration and Delivery: Visual testing can integrate with continuous integration and continuous delivery (CI/CD) pipelines. Automation scripts validate interface appearance and behavior with each code change committed into the pipeline. Providing rapid feedback within the development cycle on any UI regressions protects integrity as evolution accelerates.
In brief, Through early error detection, improved UI aesthetics and usability, and support for continuous integration and delivery, visual testing can help organizations produce high-quality applications.
Disadvantages of Visual Testing
Though visual testing has many benefits, certain restrictions and disadvantages need to be taken into consideration before using it as a testing method.
Some of the main disadvantages of visual testing are:
- Testing dynamic user interfaces: the UI changes based on user input require additional test cases and resources to validate behavior under different conditions. It can cost more and take longer to test a dynamic user interface (UI).
- Sensitivity to Minor UI Changes: Visual testing relies on precise image comparisons to baseline screenshots to identify any pixels that differ. Even minute alterations like slightly adjusting font sizes or colors can lead to test failures. These false positive results require investigation to determine if an actual regression was introduced.
- Dependency on human judgment: Manual visual testing depends on the tester’s judgment to assess whether the user interface (UI) appears and functions as intended. This may result in errors and inconsistencies which impact the precision of the test results.
Visual testing has some limitations. while being a useful testing technique, is not always efficient for accessibility testing. It can be challenging to test dynamic user interfaces, and its scope is limited. Additionally, visual testing is sensitive to changes and relies heavily on human judgment, which can lead to errors. Therefore, it is recommended to use visual testing in combination with other testing techniques to ensure thorough testing of software applications.
In closing, visual testing plays a vital role in mobile application quality assurance by validating aesthetics and consistency across platforms. Adopting visual validation best practices improves user experiences, catches regressions faster, and drives higher-quality outcomes.
Place high priority on visual testing throughout development cycles for flawless, polished mobile interfaces that fuel adoption, and growth. Consistent and appealing visuals combined with smooth reliable interactions differentiate successful mobile products. Rigorous visual validation plays a fundamental role by confirming those critical attributes are met in every release.