Many websites and applications do not work properly on all devices, leading to issues like distorted layouts, broken functionality, and poor performance. A website that looks fine on a desktop may become difficult to navigate on a mobile screen due to misalignment or slow loading times. Responsive testing helps solve this problem by checking how applications perform across different devices, screen sizes, and browsers.

A responsive checker helps run mobile-friendly tests and identify layout issues and confirm that the design adapts correctly to various screen resolutions. In this article, we will explore different cross-device testing methods, challenges, and best practices to improve application performance across multiple platforms.

What Is Responsive Testing?

Responsive website testing checks whether a website displays and functions correctly across different screen sizes and devices. It typically uses CSS media queries to adjust the layout based on the device accessing the site.

In simple terms, this testing helps verify that your website looks and works as expected on desktops, tablets, and smartphones. A site that adapts well to all resolutions creates a better user experience and gives your business a competitive edge.

Responsive testing is usually part of the final phase of a responsive web design project. It’s closely tied to cross-browser testing, since both aim to improve how a website looks and behaves under different conditions. The main difference is that responsive testing checks adaptability across screen sizes, while cross-browser testing focuses on browser-specific behavior.

​​Why is Cross-Device Testing Required?

Cross-device testing is important because users access applications from many types of devices and operating systems. Differences in screen sizes, resolutions, and OS versions affect how an application works. Testing on multiple devices helps confirm that users do not face issues while using the application.

According to Statista, in December 2022, smartphones made up 77% of mobile device sales, followed by tablets at 11.5% and smart wearables at 8.1%. This highlights the need to test applications on different device types.

Operating system differences also impact how an application functions. iOS users may experience different features or bugs compared to Android users. Statista reported that in the last quarter of 2023, Android had a 70.1% market share, while iOS had 29.2%. This shows why testing applications on both platforms is important to confirm proper functionality for all users.

How Do You Choose What Devices to Test On?

With many devices, screen sizes, and operating systems available, it is important to decide which configurations to test. Testing on every device is not possible, so the focus should be on selecting a diverse range of options that match the user base while staying within time and budget limits.

The selection of devices depends on the project requirements. In some cases, testing may be done on a single device with a specific OS and screen size. This approach is useful when an application is designed for a particular device.

Popular web analytics tools can help identify commonly used devices and operating systems. These tools provide real-time data on OS market share and screen sizes. If user analytics are available, they can help refine testing choices by focusing on the most relevant configurations.

Approaches to Perform Cross-Device Testing

Testers can use two methods for cross-device testing:

• Manual Cross-Device Testing
• Automated Cross-Device Testing

These approaches help confirm that mobile applications work properly on different devices.

Manual Cross-Device Testing

Manual testing requires testers to interact with an application like an end-user. They check usability, performance, and functionality across various devices to find issues.

Steps for Manual Cross-Device Testing

1. Select Devices: Pick devices that reflect your target audience. Cover a range of screen sizes, operating systems, and resolutions. Include both older and newer models to catch layout issues and compatibility problems.
2. Test Planning: Create a test plan with test cases for each selected device. Prioritize important functionalities and commonly used devices to speed up testing.
3. Test Execution: Testers check the user interface, navigation, and responsiveness. They evaluate the application under different network conditions like 5G, 4G, 3G, and Wi-Fi. They also test in both portrait and landscape modes. Regression testing is performed to confirm that updates do not affect functionality.
4. Documentation: Any issues found are recorded, and detailed feedback is shared with the development team.

Limitations of Manual Cross-Device Testing

• Works well for a small number of devices but becomes expensive and time-consuming for large-scale testing.
• Human errors may lead to missed issues or incorrect test execution.
• Testing consistency may vary since different testers may follow different methods.

To overcome these challenges, automated testing can be used.

Automated Cross-Device Testing

Automated testing uses tools and frameworks to test applications on multiple devices. It speeds up testing and reduces manual effort.

Steps for Automated Cross-Device Testing

1. Define Test Scenarios and Requirements: Start by identifying the devices and screen sizes you want to cover. List the test scenarios for each; these could include layout checks, navigation behavior, or functional flows like form submissions.
2. Choose Automation Tools: Pick tools that match your project needs and support the target devices and browsers. Selenium, Appium, or tools like LambdaTest are common choices for cross-device testing.
3. Create Test Scripts: Write scripts that can be reused across platforms. Keep them modular so they handle variations in UI behavior across screen sizes or operating systems. Consider writing tests in a framework that supports parallel execution to speed things up.
4. Implement Parallel Testing: Run tests on multiple devices at the same time to speed up the process.
5. Set Up Continuous Integration (CI): Integrate testing with CI/CD pipelines to automate tests with every code change.
6. Monitor Test Execution: Track test results to identify and fix failures.
7. Update Test Scripts Regularly: Modify scripts to match software updates and new device configurations.

Where to Run Cross-Device Tests?

Different testing methods help confirm that applications work properly across various devices. Below are the main options for running cross-device tests:

Physical Devices

Physical devices are actual smartphones and tablets used for testing instead of virtual versions. They cover different screen sizes, operating systems, and hardware configurations, including folding phones and wearables.

This method is useful for testing features like cameras, sensors, GPS, facial recognition, and motion detection. Testing on real devices helps find usability issues under real-world conditions. However, using physical devices for minor checks, such as verifying if an app launches correctly, may not be practical. It can also be expensive and time-consuming, especially for businesses with limited resources.

Real Device Cloud

A real device cloud provides access to Android and iOS devices over the internet. This method allows testers to run applications on real hardware without maintaining an in-house device lab.

Setting up and updating physical devices requires ongoing investment, but cloud-based services manage these tasks. Real device cloud testing supports features like biometric authentication, camera functions, Bluetooth, and sensors. It helps teams test applications without needing to buy and maintain a large collection of devices.

Emulators and Simulators

Emulators and simulators create virtual environments for testing applications. They provide a cost-effective way to check basic functionality without needing real devices.

While both serve a similar purpose, they have differences. Emulators mimic the entire hardware and software of a device, while simulators focus on software behavior. These tools help with early-stage testing and are easy to set up. They also work well in Continuous Integration (CI) environments for automated testing.

However, emulators and simulators cannot fully replicate real-world conditions. They may not support features like biometric authentication, physical sensors, or performance testing under network fluctuations. For tests requiring real user interactions, physical devices or cloud-based testing is a better choice.

Each method has its advantages and limitations, and choosing the right approach depends on the testing needs, available resources, and project requirements.

Cross-Device Testing Strategies

To effectively perform cross-device testing, effective strategies should be followed. Next, let’s look at some key strategies that can be used for cross-browser and device testing.

• Planning and Analysis: Start by identifying the target devices, operating systems, and browsers used by the customers through research and analytics. Create device matrices to prioritize testing based on usage data to confirm comprehensive coverage across different device types.
• Responsive and Adaptive Design Testing: Implement responsive design principles to make sure the application adapts to different screen sizes and orientations. Test adaptive features to confirm that different layouts and functionalities are correctly displayed and function across all targeted devices.
• Visual and Interface Testing: Conduct thorough visual testing to verify that UI elements, layouts, images, and text display correctly across all devices. Test the application’s interface usability to confirm a good user experience, especially on devices with smaller screens.
• Functional Testing Across Devices: Validate cross-platform consistency by testing all functionalities across different devices. This includes assessing how the application handles user inputs, processes data, and maintains feature accessibility across various platforms and devices.
• Performance Testing: Check load times, responsiveness, and system resource usage across multiple devices. Track CPU, memory, and battery consumption to spot performance issues that might not be visible through UI alone.
• Security Testing Across Platforms: Verify that data is handled securely during transmission and storage on all target devices. Test login flows, session handling, and permission checks to confirm that user data stays protected across platforms.
• Test Automation: Automate repetitive tests using tools to execute tests consistently across different devices and platforms. Integrate automated tests into a CI/CD pipeline to continuously verify application functionality as new code is deployed.

Challenges of Cross-Device Testing

Cross-device and browser testing comes with several challenges, including:

1. Testing across many devices and screen resolutions requires a large inventory, which can be expensive and difficult to manage.
2. Web applications must work on different browsers and versions, but frequent updates make it challenging to keep tests up to date.
3. Variations in processing power, memory, and display quality affect how applications perform. This makes it harder to test speed and responsiveness across devices.
4. Some devices support gestures or navigation methods that others do not. Testing for multiple input types adds complexity to the process.
5. Automated tests must cover multiple device scenarios, which requires setting up and managing different test environments. This increases the effort needed to maintain test scripts.
6. Creating and maintaining the necessary systems for cross-device testing requires significant investment in both infrastructure and resources.

Best Practices for Cross-Device Testing

Following best practices helps improve the accuracy and effectiveness of cross-device testing.

1. Use tools like Google Analytics and user surveys to find out which devices and screen sizes are most popular among users. Focus testing on these configurations.
2. Create a test plan that covers the most important features and operating systems. Testing critical functionalities first helps identify major issues early.
3. Use emulators and simulators for early-stage testing, but always verify on real devices. This helps confirm how the application behaves in real-world conditions.
4. Test on older devices and operating systems to check compatibility for users who have not upgraded. This helps maintain a smooth experience for all users.
5. Run tests on Wi-Fi, mobile data, and slower networks to check how the application performs under varying conditions. This helps find connectivity-related issues.
6. Collect feedback from real users to check if the application is not only functional but also easy to use. User insights help refine the overall experience.

Tools for Cross-Device Testing

Cross-device testing tools help testers make sure their applications work smoothly across different devices. Here are the top 6 tools,

• LambdaTest: It is an AI-native test orchestration and execution platform. It helps you perform manual and automation testing on over 5000+ real desktop browsers, devices, and operating system combinations.
• Appium: Appium is an open-source automation tool for testing Android and iOS applications. It supports hybrid apps and helps automate functional testing to check if an application performs as expected.
• Espresso: Espresso is a testing framework developed by Google for Android applications. It provides tools for writing UI tests that check interactions, layout, and responsiveness. It includes APIs like ViewMatchers and ViewActions to simulate user interactions.
• XCUITest: XCUITest is a testing framework developed by Apple for testing iOS applications. It allows developers to create automated tests in Swift or Objective-C to verify app functionality on iPhones and iPads.
• Robotium: Robotium is an open-source testing tool for Android applications. It helps create test cases for different scenarios, such as checking how an app responds under various conditions and whether it meets functional requirements.

When it comes to automating mobile web applications, Selenium mobile testing is a popular choice. It leverages the powerful Selenium framework, which is typically used for web applications, to test mobile browsers on real devices or emulators.

Selenium mobile testing refers to using the Selenium framework to automate testing for mobile web applications. While Selenium is primarily designed for web application testing, it can be extended to mobile testing through Selenium WebDriver with mobile browsers on real devices or emulators.

Conclusion

In conclusion, enterprise responsive testing helps confirm that applications work correctly on different devices and screen sizes. It helps deliver a consistent experience for users across smartphones, tablets, and desktops. Manual testing allows testers to check usability and functionality by interacting with applications on real devices. Automated testing speeds up the process by running tests on multiple devices at the same time.

Testing on physical devices, real device clouds, emulators, and simulators provides different ways to verify application behavior. Cross-device testing comes with challenges like managing a large number of devices and handling differences in operating systems.

Following best practices like testing on real devices, running tests under different network conditions, and automating repetitive tasks helps improve accuracy. Using testing tools helps teams check applications more efficiently. A well-planned approach to testing helps improve application quality and user experience.