Just as doctors give patients health check-ups to catch issues early, app testers inspect apps visually to ensure an intact user experience. They precisely examine each screen to verify layouts, colors, and fonts, and every design element appears perfectly to end users across different devices. Developers prioritize visual testing to simulate user interaction and carefully inspect whether the user interface looks as precise as intended across platforms. They authenticate that intentional design changes are correctly implemented while calling out unintended visual side effects that creep in during development.
Visual testing or Visual regression 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. Visual testing is considered the most precise and fastest method for app creators to verify whether a particular component renders correctly or leads to visual regression. It greatly expedites work and enables developers to receive bug reports much more quickly by automating the view-checking process.
In this article, we will explore the significance of visual testing for mobile apps and visual testing tools.
So, let’s get started!
Visual Testing for Mobile Apps
When people come across your mobile application, they are most likely to respond in 3 ways- positively, negatively, or with amazement. It will be great if your aim is the last one, as it is the most desired.
If users find an app that is visually appealing to them, even if they do not use it for a very long time, they surely will go through it once and check the interface. It’s the human tendency to react to visually attractive or appealing things. Thus, visual testing will help find the visual bugs.
Visual testing is critical for mobile apps to ensure a flawless user experience across the market fragmentation of devices, operating systems, and form factors. It involves automatically capturing and comparing screenshots of key user flows on real mobile devices to detect layout errors, responsiveness issues, clipping, overlapping elements, and other visual defects. Engineering teams configure visual testing suites to represent target phone and tablet models running iOS and Android OS versions that cover their user base.
As development progresses, visual testing identifies deviations from platform guidelines and style guides. It also safeguards brand integrity with consistent colors, fonts, graphics, and other design elements. Fast feedback on visual quality gives teams confidence that UI changes ship free of regressions. Automating visual captures and analysis makes this rigorous testing scalable across iterations. With mobile apps, the visual experience is central to adoption – and visual testing plays a fundamental role in shipping appealing and functional designs tuned meticulously for their audience.
Visual mobile testing can be approached through both manual and automated methodologies. Each of them has its strengths and is often used in combination to achieve comprehensive test coverage.
- Manual Testing:
Manual Testing relies on manual examiners inspecting an application’s visual elements across platforms and devices. Testers carefully inspect each interface, screen, and component to catch subtle defects like layout problems, color inconsistencies, or design deviations that automated tools might miss. This method validates aesthetics, ease of use, and general usability. It also confirms specific features and user-reported bugs. Overall, manual testing is essential for assessing nuanced visual quality.
- Automated Visual Testing:
Automated Visual Testing employs software to capture and compare app screenshots against baseline references automatically. Divergences signal potential flaws for further inspection. This process efficiently finds visual inconsistencies across device types, platforms, and screen sizes by simulating actions like rotation and brightness changes. Automated testing quickly validates visual conformity and responsiveness.
Why is Visual Testing Important for Mobile Apps?
No matter how accurate your application is, it is useless without an exceptional user interface and user experience. Here are some of the key reasons why visual testing is important for mobile apps:
- Mobile apps need to work flawlessly across thousands of device types with varying screen sizes, resolutions, and form factors. Visual testing ensures visual consistency.
- Visual testing verifies that fonts, colors, layouts, and overall styling appear correctly, preventing jarring inconsistencies that frustrate users. Tests confirm designs are accessible with adequate color contrast and text sizing. Visual testing is crucial for creating intuitive interfaces that delight users.
- Shorter release cycles necessitate automated testing to catch issues early. Visual regression does this for UI-related defects.
- By comparing screenshots against baselines, visual testing quickly flags distortions, mismatches, and rendering flaws. This enables rapid identification and remediation of defects before they reach end users. Visual testing prevents regressions and promotes consistent visual integrity over ongoing development.
- Automated visual testing liberates testers from tedious and repetitive manual validation. By highlighting inconsistencies, tests enable efficient and scalable coverage across countless device configurations and operating systems.
- Visual testing unites designers, developers, and testers by providing clear visualizations of issues. This facilitates productive discussions and refinements, creating cohesion and bolstering app quality.
- Visual testing delivers significant time savings in the quality assurance process. By preserving test cases as visual screenshots, software does not need full re-testing once fixes are implemented. Visual tests only focus on potential visual defects, reducing prep time compared to comprehensive functional validation.
By ensuring visual integrity and defect-free interfaces, visual testing is crucial for delighting mobile users.
Tools for Visual Testing
Here are some of the most popular visual testing tools that can be used for testing the visual UI of your mobile application.
LambdaTest
LambdaTest is an AI-based test orchestration and execution platform for conducting visual testing. Its main feature is providing a wide range of real browsers and operating systems to facilitate visual testing in diverse settings. It is made to function using the Selenium Automation Grid. Since it removes the need for internal maintenance of a Selenium infrastructure, online and cloud-based could be the buzzwords of choice here.
- LambdaTest offers a versatile testing platform for cross-browser testing needs to automate the visual UI of mobile apps across 3,000+ real desktop and mobile environments.
- With AI-powered smart visual testing, this platform assists developers and testers in finding visual user interface regression issues with just one click. Its smart image-to-image comparison feature lets you spot minimal visual bugs easily by simply uploading screenshots and running the test.
- LambdaTest makes it easier to compare screenshots of websites across browsers and identify visual differences. LambdaTest is a great option for visual testing tools because of its high browser coverage, rapid test execution, and quicker release schedule. The best part is that LambdaTest can easily integrate with a full CI/CD tech stack using various testing frameworks such as Playwright, Puppeteer, Appium, Cypress, and Selenium.
LambdaTest provides the needs of web developers and quality assurance teams seeking to perform cross-browser visual testing to detect and resolve any visual defects across different browsers and devices.
Kobiton
Kobiton is a mobile testing platform that provides complete visual validation and visual UX Testing solutions. It aims to find visual flaws in mobile user interface and user experience. It finds functional and visual imperfections that the human eye would miss otherwise.
- It provides real-world, automated, and cloud-based mobile app testing and on-premise testing.
- With Kobiton, you can automate test cases, verify UX and UI on all mobile devices, and replay scenarios that replicate problems without knowing or utilizing a single line of code.
- Kobiton is an excellent tool for users of all skill levels since it combines testing automation, coverage, management, and remote enablement into a user-friendly platform. With Kobiton, you can instantly access over 350 real devices and your private cloud or local lab.
- Kobiton can be integrated with Jira Software, Xebialab, Travis CI, TeamCity, Jenkins, Azure DevOps, Jetbrains, and CircleCI.
Applitools
Applitools offers an innovative visual testing and monitoring solution tailored for web and mobile apps. Applitools utilizes visual AI to automate the identification and catching of visual defects in apps – integrating tightly with modern software testing workflows.
- “Applitools Eyes” is a cloud service offered by Applitools for automated visual user interface testing of desktop, mobile, and web applications.
- It checks the visual output of the user interface on different browsers, platforms, screen sizes, and other configurations.
- It Supports features like cross-browser testing, full-page screenshots, and page layout matching.
- Some of the many well-known automated testing frameworks and languages- Selenium IDE, Selenium, Cypress, WebdriverIO, and TestCafe are supported by Applitools.
- Using this tool, you can quickly create visual test cases to add to your CI/CD pipeline for continuous integration and delivery, which is integrated with DevOps.
Applitools is beneficial for organizations aiming to automate visual testing and continuously monitor applications’ visual appearance.
Appium
Appium reduces mobile test code maintenance by extending Selenium’s foundations to support automated user interface and end-to-end validation efficiently across platforms.
- Open source automation protocol extending Selenium WebDriver to simplify UI test scripting across native, hybrid, and mobile web apps.
- Supports all major scripting languages Java, Ruby, Python, PHP, JavaScript, C#.
- Plugs into CI/CD pipelines like Jenkins, and CircleCI, integrate with test runners like TestNG, and frameworks like Cucumber.
- No need to recompile or modify target mobile apps or test suites to adopt Appium automation.
- The “Write Once, Run Anywhere” principle enables test reuse across iOS, Android, and Windows platforms.
- Actively maintained open-source projects with strong community support and an extensive documentation knowledge base.
Selenium
Selenium is an Open source test automation framework that can be used for visual testing. To improve the quality and appearance of applications, Selenium acts as an interface between developers and testers, creating a harmonious environment where functionality and aesthetics meet.
- Open source test automation framework enabling free web, mobile, and desktop test automation.
- Highly modular architecture allows easily adding libraries and extensions like computer vision.
- Tight integration with all main unit test runners – TestNG, JUnit, Mocha, Jasmine, PHPUnit, etc.
- Image comparison and processing libraries to detect UI regressions.
- Detailed element selectors and hooks to validate text, layout, and responsiveness.
- Active slack community and comprehensive documentation for self-service.
- Plugin ecosystem around visual testing with sample image repositories.
Conclusion
In conclusion, visual testing stands as a keystone in the search for delivering high-quality mobile apps. Its integration into the regression testing process is not just a best practice but a necessity in the ever-evolving landscape of mobile app development. By prioritizing visual testing, developers can fortify their applications against UI discrepancies, ultimately providing users with a visually pleasing and consistent experience across diverse devices and platforms. As technology advances, visual testing will only become more integral, contributing to the creation of mobile apps that captivate users with their functionality and visual allure.