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We live in a mobile-first era. With more than 10.37 billion mobile connections worldwide, delivering high-quality mobile experiences is a must. As user expectations rise, mobile testing becomes a critical discipline for ensuring reliability, usability, and performance across an increasingly diverse device ecosystem.
This guide is designed to help testers at any level understand and begin working with mobile testing. It covers the essential concepts, techniques, and processes you need to build a solid foundation.
Here’s what we’ll explore:
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What is mobile application testing?
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Why mobile testing matters
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Types of mobile testing
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Manual mobile testing
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Automated mobile testing
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The mobile testing process
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Mobile testing best practices
What is Mobile Application Testing?
Mobile application testing is the process of evaluating apps designed for mobile devices to ensure they work as intended. Its primary focus is to validate functionality, usability, and overall stability.
In today’s competitive market, thorough mobile testing is essential for an app’s success. Beyond core functionality, applications must also be tested for performance, security, and user interface quality to deliver a reliable, satisfying experience to end users.
Types of Mobile Apps
There are three major types of mobile apps:
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Native apps – Built specifically for iOS or Android using platform-specific languages and tools. They offer high performance, full access to device features, and a smooth user experience.
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Hybrid apps – Created using web technologies (HTML, CSS, JavaScript) and wrapped in a native container. They run on multiple platforms with a shared codebase but may not match the performance of native apps.
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Mobile web apps – Web applications accessed through a mobile browser. They require no installation and work across platforms, but their performance and capabilities depend on the browser and network quality.
Examples of mobile app testing
Here we'll use Flappy Bird as an example of how to test mobile apps:
Despite its simple gameplay, the app still needed proper testing before being released on Google Play or the App Store. If you are a mobile app tester trying to test Flappy Bird on both iOS and Android, here are the tasks you need to do:
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Identify Flappy Bird’s core features and behaviors.
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Prepare the devices needed for testing (Android and iOS). If physical devices aren’t available, you would use cloud-based testing environments.
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Test the pipe generation logic. Is the spacing between pipes consistent and fair?
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Test the controls. Does the bird flap and ascend the correct distance with each tap?
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Test collision detection by intentionally hitting pipes to verify that the game registers the collision accurately.
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Confirm scoring logic. Each time the bird passes a pipe, does the score increase by one?
Once these checks are complete, you’ve covered the functional testing for the game. The next step is non-functional testing, such as performance testing, load testing, or security testing. After that, you would also validate the game across different devices and operating system version.
This is mobile app testing in action. Flappy Bird is simple enough to test manually, but as mobile apps become more complex, relying solely on manual testing quickly becomes impractical.
Benefits of mobile app testing
Here are some of the key benefits of why you should test mobile apps:
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Improves app stability: Thorough testing helps identify defects early, reducing crashes, unexpected behavior, and performance issues before users ever see them.
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Ensures consistent user experience: Mobile testing verifies how the app behaves across different devices, screen sizes, and operating systems, ensuring users get a smooth and predictable experience no matter what device they use.
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Boosts user satisfaction and retention: Even small bugs or UI issues can frustrate users and lead to uninstalls. Testing helps eliminate friction points, making users more likely to keep and recommend the app.
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Protects user data and strengthens security: Security testing uncovers vulnerabilities such as insecure data storage, weak authentication, or unsafe API communication, reducing the risk of attacks and data breaches.
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Enhances performance under real-world conditions: Testing evaluates how the app performs with slow networks, heavy usage, background processes, and low battery conditions, all of which affect the real user experience.
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Reduces long-term development and maintenance costs: Detecting and fixing issues early is significantly cheaper than resolving them after launch. Testing helps avoid costly rework and emergency fixes.
Challenges of mobile app testing
1. Device fragmentation
Mobile devices are highly diverse, and that diversity makes mobile testing essential. There are four primary reasons why mobile testing is necessary:
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Variety of device specifications
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User experience and satisfaction
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Security and privacy
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Competitive advantage
Not all smartphones are the same. Screen resolutions vary widely, from 480×800 to 1080×1920 and beyond, and even within a single brand like Apple, display sizes and dimensions differ significantly. This variety benefits users but creates challenges for testers, as UI layouts can break easily if proper responsive design and testing practices aren’t followed.
2. Third-party integrations
Many organizations assume that third-party components will function flawlessly once integrated, but this isn’t always the case. Mobile environments change frequently: updates to OS versions, device hardware, or network conditions can disrupt these integrations. This makes it essential to thoroughly test every third-party service to ensure they behave consistently and provide a seamless experience for users.
3. App security
With external threats increasing, protecting sensitive customer and organizational data is becoming more challenging. Any weakness in the application can expose it to cyberattacks, data leaks, or unauthorized access. Security testing is therefore critical. Testing should verify that sensitive data is properly encrypted, securely stored, and safeguarded against malicious activities at all times.
4. Battery life
Although mobile batteries have improved significantly in recent years, modern apps also demand more power due to richer features and higher processing requirements. QA teams must evaluate how much battery the app consumes, especially during resource-intensive operations. Testing should cover multiple scenarios: active use, idle states, and background execution. Excessive battery drain is one of the top reasons users uninstall apps, so ensuring efficient power consumption is crucial for user retention.
Types of Mobile Testing
There are many mobile testing types to account for when validating an application:
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Functional testing – Ensures the app delivers its intended features. This includes not only checking individual functions but also verifying how data is processed and handled in the backend.
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UI testing – Confirms that the visual elements of the app render correctly and match the expected design. Testers compare the actual interface with the intended version to identify inconsistencies; this is also known as visual testing.
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Integration testing – Verifies that different components of the app work together without conflict. Features often depend on one another, and this testing ensures smooth interaction between integrated modules.
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Compatibility testing – Checks how well the app performs across various devices, operating systems, screen resolutions, and hardware types.
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Usability testing – Evaluates how intuitive and user-friendly the app is, focusing on ease of navigation, clarity, and overall experience.
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Localization testing – Ensures the app behaves correctly for different languages, regions, currencies, and cultural formats.
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Accessibility testing – Confirms that users with disabilities can successfully use the app, following recognized accessibility standards.
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Interrupt testing – Assesses how the app reacts to real-world interruptions such as calls, notifications, alerts, and background tasks.
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Installation and update testing – Validates that the app installs, updates, and uninstalls smoothly, with user data preserved where intended.
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Network testing – Examines app performance under different network conditions, including slow, unstable, or completely offline scenarios.
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Memory and storage testing – Measures how much RAM and storage the app consumes to prevent crashes or sluggish performance.
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Compliance testing – Verifies that the app meets industry regulations, platform requirements, and internal policy standards.
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Recovery testing – Checks how effectively the app recovers from failures such as crashes, forced restarts, or unexpected shutdowns.
Approaches to Mobile Testing
Manual mobile testing
Manual mobile testing involves a tester directly interacting with the mobile app to execute test cases without relying on scripts or automation tools. The tester performs all actions (navigation, input, verification, and observation) manually on the device or emulator.
The good:
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Ideal for simple or early-stage projects: For lightweight apps like Flappy Bird, it would be unnecessary overhead to build a full automation test suite. Manual testing is perfectly suitable for applications with straightforward features.
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Allows deeper exploration: Manual testing enables testers to freely explore the application, follow unexpected paths, and uncover issues that automated scripts are not designed to check. This makes it valuable for catching complex, subtle, or unpredictable bugs.
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Lower learning curve: Manual testers don’t need advanced coding skills or complex tooling. Testing can begin immediately after installing and launching the app.
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Lower maintenance effort: Automation requires constant script updates whenever the app UI or logic changes. Manual testing avoids this maintenance burden and remains reliable without continuous refactoring.
The bad:
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Not practical for complex applications: Large-scale apps like Amazon’s mobile app contain countless features, flows, and data combinations. Testing them manually becomes inefficient and unrealistic.
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Slow and difficult to scale: Human testers can only execute one test at a time, and their speed is limited. Covering all possible scenarios or devices requires significantly more time and resources.
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Becomes resource-heavy over time: As the app grows, manual testing becomes increasingly expensive and time-consuming, often outweighing its initial simplicity.
Best practices:
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Combine manual and automated approaches: Manual testing is best for initial exploration and discovering new bugs; automation should take over once a test becomes repetitive and stable.
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Use exploratory testing early: When first evaluating an app, manual exploratory testing helps testers learn the product and uncover unexpected issues quickly.
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Focus on complex or UX-related scenarios
Manual testing is ideal for validating user experience, usability concerns, and intricate workflows that require human judgment.
Automated mobile testing
Automated mobile testing uses scripts or testing tools to run predefined test cases automatically across devices and environments. Scripts replicate user interactions, validate outcomes, and execute tests at scale.
The good:
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Enables faster release cycles: Automated tests can run hundreds of test cases with a single click, dramatically reducing the time spent on repetitive validation.
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Highly scalable: As the application grows, automation can expand alongside it without requiring a proportionate increase in testers.
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Essential for regression testing: Every update requires verifying that existing features still work as expected. Automated testing handles regression checks efficiently and reliably.
The bad:
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High initial setup cost: Building an automated testing framework requires time, specialized skills, and tool integrations. Teams need to invest in coding, configuration, and environment setup.
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Ongoing script maintenance: Apps evolve quickly and new features often break existing automated tests. Keeping the test suite reliable requires continuous updates and refactoring.
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Limited ability to detect unexpected issues: Automation only checks what it’s programmed to check. It cannot explore the app intuitively, notice subtle UI flaws, or detect issues outside its scripted expectations.
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Over-automation risks: Automating everything can lead to brittle, unstable tests that deliver false failures. Teams must carefully choose which test cases are worth automating.
Best practices
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Automate stable and repetitive scenarios first: Focus on regression tests, core workflows, and high-frequency actions. Leave rapidly changing or unclear features for manual testing.
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Keep tests simple and modular: Well-structured test scripts are easier to update and less prone to break when the UI changes.
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Maintain a balanced strategy: Automation is powerful, but it cannot replace human judgment. Combine automated tests with manual exploratory testing for full coverage.
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Monitor and refine regularly: Review and update test scripts to ensure they remain aligned with app changes and evolving user flows.
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Run automation early in the CI/CD pipeline: Integrating automated tests into the build process helps catch issues immediately and prevents faulty code from moving forward.
The Process of Mobile Testing
Step 1. Choose which test cases to run manually and which to automate
A balanced, hybrid approach that combines both manual and automated testing delivers the best coverage and efficiency. This decision-making process happens during the test planning phase. To determine whether a test case is suitable for automation, consider the following criteria:
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The test case is executed frequently and repeatedly.
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It requires a high degree of accuracy or consistency.
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The scenario is heavily data-driven. For example, entering hundreds or thousands of search queries in an eCommerce app to verify whether the results are relevant.
All test cases should be documented and organized in a test case management system. This allows teams to categorize them effectively, assign tags, and maintain clear taxonomy for easy tracking and planning.
Step 2. Choose the suitable framework or tool
Selecting the right framework or tool is a crucial part of setting up your mobile testing approach. The choice depends heavily on your team’s skills, the project requirements, and how much flexibility or convenience you need.
You generally have two main paths:
1. Use an open-source mobile testing framework
These frameworks provide prebuilt APIs and syntax that simplify the underlying automation code. When you have access to the mobile app’s source code, native frameworks are typically the most powerful and efficient options.
Common choices include:
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Espresso (Android): Espresso is the native UI testing framework for Android. Because it's tightly integrated with the Android ecosystem, it gives testers precise control over UI elements and runs tests quickly. Its seamless connection to JUnit in Android Studio makes execution and organization easier, as tests live directly within the app’s project.
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XCUITest (iOS): This is the native testing framework for iOS. Similar to Espresso, it offers fast execution, robust libraries, and reliable compatibility with iOS development tools. It fits naturally into CI/CD pipelines and supports stable, high-performance testing.
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Appium (cross-platform): Appium is built on top of Espresso and XCUITest, offering a unified approach for both Android and iOS. It’s ideal if you want to minimize duplicated work across platforms, though you may sacrifice some speed and efficiency compared to using each native framework individually.
2. Use an automated mobile testing tool
Testing tools offer a more streamlined experience. They often provide point-and-click test creation, device farms, CI/CD integration, visual management dashboards, and optional scripting for advanced customization.
Compared to raw frameworks, tools focus on usability and speed up the process significantly, especially for teams with mixed technical backgrounds.
How to decide?
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Choose a framework if you have an experienced engineering team familiar with coding, and you need deep control over the test environment.
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Choose a tool if your team includes testers of varying technical expertise, or if you want faster onboarding, a simpler setup, and more convenience without sacrificing advanced capabilities.
In many cases, teams benefit from using both: leveraging frameworks for complex, code-level testing while using tools to accelerate broader automation and execution across devices.
Step 3. Choose your testing environment
Selecting the right testing environment is essential for obtaining accurate, reliable, and scalable results. There are three primary approaches to consider:
1. Real mobile devices
Testing on physical devices provides the highest level of accuracy because you validate the app under real-world conditions: actual hardware, sensors, performance characteristics, and network behavior.
Both manual and automated tests can be executed on these devices. The downside is cost: purchasing, updating, and maintaining a large device inventory can quickly become expensive and difficult to manage.
2. Emulators and simulators
Emulators (Android) and simulators (iOS) replicate device configurations using virtualization technology. They’re easy to set up, fast to launch, and ideal for early-stage development or quick functional checks.
However, they can’t fully replicate real device behavior like performance, battery usage, hardware sensors, and certain OS-level interactions may differ from actual results on physical devices.
3. Cloud-based device farms
Device farms allow teams to test applications on real mobile devices hosted in the cloud. This approach provides broad device coverage without the overhead of maintaining physical hardware. It offers much higher realism than emulators or simulators while enabling both manual testing and automated execution at scale.
A cloud-based environment delivers on-demand access to a wide range of device models, OS versions, and configurations, making it a powerful solution for cross-device testing.
Step 4. Think about test case management (TCM)
Test case management, when done correctly, can significantly elevate the quality and efficiency of a project.
If you choose a manual testing approach, you’ll need a clear system for organizing your test cases. For small teams, a simple spreadsheet may be enough. For larger teams or more complex needs, tools like Jira or dedicated test management platforms such as TestRail provide better structure and traceability.
These systems help QA teams track test execution, record results, monitor progress, and generate detailed reports. The limitation, however, is that traditional test case management often becomes siloed.
With automated testing, TCM can be integrated directly into the process. When a test case is written, its metadata and taxonomy can automatically update inside the test management system. As tests run, results can sync back in real time, providing a streamlined, end-to-end workflow that reduces manual overhead and improves visibility across the team.
Step 5. Write your test cases
This is where the actual testing work begins.
If you’re using a framework, start by reviewing its documentation and learning the basic syntax. For example, Espresso documentation for Android and XCUITest documentation for iOS provide guidance on how to structure tests, interact with UI elements, and build stable test scripts.
One of its strengths is the rich set of view matchers and actions that allow you to locate and interact with UI components. View matchers help you identify elements based on attributes such as IDs, text labels, or content descriptions. Actions then let you simulate user interactions such as tapping, typing, or swiping.
In practice, you might use ViewMatchers.withId to target the username field, apply a typeText action to input a value, then locate the login button and apply a click action. It’s direct, readable, and designed to mirror real user behavior, making UI testing intuitive and efficient with Espresso.
Mobile Testing Best Practices
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Establish a clear mobile testing strategy and define specific objectives before beginning any test activities.
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Conduct UI testing on real mobile devices, not solely on emulators or simulators, to ensure accurate results.
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Apply testing early in the development cycle and continue testing consistently as the app evolves.
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Prioritize testing on key devices, operating systems, and network conditions, since testing every possible combination is unrealistic.
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Perform adequate performance, stress, and security testing to validate app stability and resilience.
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Include tests that evaluate interoperability, battery usage, and fault tolerance to ensure the app behaves reliably under real-world conditions.
How to choose a good mobile testing tool?
At the end of the day, good mobile testing is about ensuring that the product works consistently across
Selecting the right mobile testing tool depends on your app’s requirements, your team’s skills, and your long-term testing strategy. Here are the key factors to evaluate:
1. Platform and device coverage
A good tool should support testing across the devices, OS versions, and screen sizes your users rely on. Look for support for both Android and iOS, plus access to real devices (local or cloud-based).
2. Ease of test creation
The tool should match your team’s skill level.
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If your team has strong coding skills, look for tools with flexible scripting.
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If your team is less technical, low-code or no-code test authoring can speed up adoption.
3. Automation capabilities
Check whether the tool supports automated testing at scale, parallel execution, and integration with common automation frameworks (Espresso, XCUITest, Appium, etc.).
4. Integration with CI/CD pipelines
A good tool must integrate smoothly with Jenkins, GitHub Actions, GitLab CI, Azure DevOps, or whatever CI/CD system your team uses. This ensures reliable, continuous testing.
Conclusion
With the growing diversity of mobile hardware and the rising expectations of users, teams need a structured approach, the right testing strategy, and tools that support both manual and automated workflows.
Choosing a capable mobile testing platform can make a significant difference in test coverage, execution speed, and long-term maintenance. This is where Katalon stands out.
Katalon provides an all-in-one solution for mobile, web, and API combining low-code test creation with advanced automation capabilities. With support for real devices, cloud execution, and seamless integration with CI/CD pipelines, Katalon helps teams of all skill levels build scalable, efficient, and reliable mobile testing processes.
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