Mobile App Testing: A Guide to Essential Types for Optimal Quality

The mobile application industry has absolutely exploded in recent years. As smartphones, tablets, and wearables continue rapid global adoption, apps have become integral across consumer and business use cases.

However, with over 77 billion mobile app downloads in the first half of 2023, standing out requires building incredibly polished user experiences that convert and retain customers.

This is why comprehensive testing is crucial throughout development. Rigorous QA validates functionality, usability, and performance so developers can fix issues pre-launch. As leaders in mobile app testing, we enable you to release quality apps that delight your users.

Below, we cover key testing types across the spectrum to help ensure excellence in your next customer or employee-facing mobile app experience.

Types of Mobile Testing

Properly testing apps takes looking at the problem from multiple angles. Validating correct functionality is crucial, but ensuring top-notch user experience takes testing even deeper… Here are the main types of mobile app testing widely used these days.

Functional Testing

Validating that an app works exactly as intended is the basis of quality assurance. By running targeted test cases during coding sprints, functional testing confirms that specified components, user flows, calculations, and system integrations exhibit the correct behavior according to specifications on target devices and platforms.

• Unit testing focuses on verifying individual code components, like classes and methods, at a granular level. By inspecting small units in isolation, quality engineers can identify bugs early during development when they are easier to rectify. This prevents system-spanning defects down the line.
• Advancing further, integration testing confirms cohesive interoperability of combined code units across platform native APIs, third-party libraries, backend connections, and core business logic flows. Testing bundled components early catches integration defects before impacting downstream teams.
• Progressing further, system testing evaluates end-to-end compliance of the fully integrated application to validate that interconnected systems deliver the right collective functionality. QA specialists script targeted test cases based on priority user stories to catch gaps.
• Regression testing is also important for comparing an application’s behavior before and after engineering modifications are made. By re-running validation test suites after changes, it detects new defects that may have surfaced inadvertently due to code or configuration alterations. This type of mobile app testing protects integrity.
• Finally, smoke testing is broad testing performed to quickly reveal major flaws early on before investing further in QA efforts. It provides an initial signal check by executing basic test scripts spanning critical functionality.

While functional testing forms the imperative backbone of app QA, assessing non-functional aspects is equally necessary for holistic quality…

Non-Functional Testing

Though crucial for compliance, functionally correct behavior alone doesn’t guarantee software excellence. Non-functional characteristics profoundly influence how users perceive interactions like convenience, novelty, and overall brand quality.

• Performance testing mirrors real-world usage patterns across target devices, assessing optimized frame rendering, download sizes, data caching, battery/CPU impact, etc.
• Usability testing recruits representative target users to assess workflow intelligibility, ease of navigation between views, and clarity of UI element signifiers and interactions via techniques like think-aloud protocols. This type of mobile application testing yields actionable insights to streamline and optimize interfaces to best meet consumer needs.
• Accessibility testing audits mobile application compliance with disability laws and regulations. QA analysts validate accessibility support for assistive tools like screen readers and standard inputs, while lawyers assess policy adherence.
• As cyber threats proliferate, security testing attempts to hack into the mobile app through means like authentication bypass, network manipulation, vulnerability probing, and authorization elevation.
• Compatibility testing executes the application on different mobile hardware, platforms, and browser environments based on target market share statistics, right from feature phones to the latest flagships. This type of mobile testing ensures ubiquitous operability.
• Localization testing then checks region-specific app adaptations, including translation accuracy, cultural norms, geography-appropriate imagery, and country-customized functionality. Covering nuanced local needs drives international expansion.

Once functionality and experience are validated, testing on actual user devices is pivotal…

Device-Specific Testing

Testing mobile applications across the wide variety of devices and operating systems poses significant challenges. With thousands of different Android devices and several iOS device variants, ensuring an application works properly on all target devices is critical yet difficult.

A key challenge is accounting for different screen sizes and resolutions. An app may display perfectly on one device but have formatting or usability issues on another. Testing needs to cover all targeted phone and tablet sizes. Emulators can help test multiple configurations, but real devices are still preferred for final validation.

Performance testing also varies across devices. Lower-end phones may struggle with features that work fine on flagship devices. Network connectivity can also impact performance if an app requires internet access. Testing needs to confirm acceptable functionality across budget and high-end devices alike.

Let’s take a look at several types of device-specific testing to address these challenges and beyond.

Android Testing

Mobile application testing specifically for Android requires covering the extensive device and OS fragmentation in the ecosystem. With thousands of unique phone and tablet models running various versions of Android OS, testing is extremely challenging.

Emulators and real test devices should include both high and low-end hardware specs to mimic consumer devices. Testing needs to validate not just app functionality but performance across different chipsets and memory constraints, as lower-powered Android devices are still very common globally.

Testing also needs to span Android OS releases from newer versions back at least three to four years due to many older devices still being actively used by consumers. Features like widgets and notifications as well as battery optimization also need to be tested based on app capabilities across OS versions.

iOS Testing

While iOS testing involves fewer total devices and OS versions than Android, properly testing iOS mobile apps has its own challenges.

Apple releases a new iPhone model annually, often with new iOS releases adding and updating features like Siri, camera integration, and new framework APIs. Keeping pace with the latest iOS and device features takes significant and consistent effort.

Testing teams should obtain at least one current and one previous generation iPhone upon major iOS updates for hands-on testing, as well as utilize cloud device farms to test across multiple device generations. Simulators can assist with initial testing across iOS versions.

Because Apple oversees the entire iOS ecosystem, testing teams don’t need to account for the fragmentation common with Android. However, iOS still requires extensive user interface testing for different device sizes, validating consistent performance across hardware specs, and confirming new iOS features work properly or have acceptable fallback logic.

Cross-Platform Testing

For mobile apps developed using cross-platform frameworks like React Native, testing needs to validate consistent functionality across both iOS and Android platforms. Areas like UI rendering, data access, and device API integration need equivalent behavior irrespective of OS and devices.

Cross-platform requirements add complexity on top of the existing testing needed for native Android and iOS apps. Testing budgets often don’t account for this expanded scope, so teams must work smarter when validating cross-platform apps.

Leveraging automated testing, cloud testing environments, select physical test devices, and emulator sandboxes can provide efficient combinational testing. Teams should focus manual testing on OS-specific feature validation and user flows. Upfront simulator testing can catch app crashes early.

The complexity of cross-platform validation reiterates the importance of developing modular, maintainable code from the start of a project. Well-structured code and thorough unit and integration testing enable easier debugging and testing further in development cycles when multi-platform considerations amplify.

Conclusion

Compromising on quality threatens an app’s survival, but apps hardened through testing have the resilience to evolve with shifting user needs over time.

Testing mobile apps effectively takes skill, diligence, and the right combination of testing types. With the right selection of mobile testing type, you can develop optimal testing strategies.

Our flexible testing solutions blend release velocity, actionable feedback, and reliability for delightful and resonant apps. To learn more about our end-to-end quality assurance services, contact us today for a personalized consultation or project estimate.