Mobile Application Testing Types and Approaches

Testlio

January 15th, 2024

Users download billions of apps every year, and according to forecasts, the number of downloads across all mobile app categories will continue to increase within the next three years. The bad news is that over half of all downloaded apps get uninstalled within 30 days. The reasons vary:

• App not in use: 39.9%
• Limited storage: 18.7%
• Excessive notifications: 12.6%
• Confusion: 5.4%
• Technical issues: 5.4%

What these numbers represent is crystal clear. Because mobile devices have inherently low storage capacity, it’s bound to get uninstalled if your app is no longer relevant to the user. Similarly, if your app introduces technical difficulties—it doesn’t matter if it’s just a slight inconvenience—users are likely to uninstall it to look for a more user-friendly alternative. 

What Is Mobile Application Testing?

Mobile app testing is a strict testing process to ensure mobile apps meet and exceed quality, usability, and user expectations. It involves evaluating and validating mobile applications across various devices, platforms, and operating systems to uncover defects, optimize performance, and deliver a seamless user experience.

It requires a comprehensive approach that combines and iterates on multiple types of testing

In the past, mobile app testing primarily focused on functional testing, verifying if apps met their intended purpose. However, this process has come a long way and mobile application testing approaches now include many different types of testing.

Knowing the different mobile app testing types and how they uniquely contribute to delivering an exceptional end-user experience is an excellent place to start. 

13 Mobile App Testing Methodologies

1. Functional Testing 

Functional testing involves evaluating an application’s features and functions to ensure they work as expected. Testers assess core functionalities throughout all the user flows to identify and eliminate functional bugs that are inadvertently introduced during the software development process. 

Examples of functional testing include validating whether:

• The application installs and launches correctly
• Users can sign up and log in
• Text boxes and buttons function properly
• Push notifications render correctly

2. Compatibility Testing

Compatibility testing checks if an application functions as intended across various platforms (e.g., a combination of different devices, operating systems, browsers, databases, and network environments). The goal is to identify and resolve any performance issues to prevent users from running into navigation, screen size adaptation, button placement, and other compatibility-related problems. 

For example, cross-browser compatibility testing ensures that an application functions correctly and consistently across different web browsers, while database compatibility testing verifies that the application works seamlessly with different databases or database management systems (DBMS). 

3. Localization Testing

From language translations to currency conversions to cultural preferences, ensuring the app delivers a consistently delightful experience across all markets is crucial. That’s when localization testing comes into play, check out our guide on localization testing.

Today’s consumers will boycott applications that fail to consistently translate graphical and text elements in a way that is highly inclusive of local languages and cultures. According to research conducted by Data.ai (formerly AppAnnie) on the global mobile gaming market, fully localizing the application experience is how brands can get a leg up on the competition.

Localization testing relies on native language speakers and focuses on uncovering a range of issues, including:

• Unnatural translations
• Cultural relevance and accuracy
• Currency, symbols, and pricing
• Overlapping UI elements

4.  Interruption Testing

Interruption testing evaluates how well an application can recover from unexpected interruptions. Although interruption testing applies to any type of application (web, mobile, standalone, etc.), it’s more common in mobile applications because of mobile’s unique characteristics: diverse hardware, various connectivity scenarios, battery life, etc.

Examples of interruptions to test include:

• Incoming phone calls when an application is running
• Incoming messages or SMS when an application is running
• Battery life when an application is running
• The device is plugged in or out of charging when an application is running
• The device shuts down when an application is running
• OS upgrade occurs when an application is running
• Loss and restoration of the network while an application is running

5. Performance Testing

Delivering a world-class digital experience to your users requires a consistently performant application across an ever-evolving range of end-user traffic patterns, network access locations, and device configurations. A slow or unreliable user experience – no matter how functionally complete or elegantly designed – is a bad user experience. 

Consider research from digital marketing agency Portent that determined e-commerce website transaction conversion rates dropped from 3.05% to 0.67% as page load times increased from 1 second to 4 seconds. 

Types of performance testing include: 

• Load testing: Assess whether the application can handle the expected maximum number of users or transactions 
• Endurance testing: Evaluate application performance and stability over an extended period
• Stress testing: Evaluate the application’s behavior under extreme conditions to determine failure thresholds or breaking points
• Spike testing: Assess whether the application can handle sudden increases in user activity

6. Security Testing

Security testing is another crucial type of mobile app testing that focuses on identifying and addressing application weaknesses and vulnerabilities. The goal is to make sure the app can withstand various forms of attacks and any unforeseen failures.

There are several types of security testing, including:

• Vulnerability scanning: Identify known vulnerabilities that attackers can exploit, such as misconfigurations or outdated software versions
• Penetration testing: Simulate real-world attacks to pinpoint potential security flaws
• Security code review: Check for security vulnerabilities in the source code
• Ethical hacking: Employ skilled security professionals to mimic the actions of a hacker and identify vulnerabilities

7. Payments Testing

If your application processes financial transactions, payments testing is a critical testing type. Payments testing validates the security and reliability of financial transactions conducted by end users within a mobile app. Not only is this area of testing critical for ensuring a positive end-user experience, but it is also paramount from a compliance and regulatory perspective. 

Gaining confidence in the integrity of financial transactions involves a range of test cases, from ensuring that end users are presented with the appropriate set of payment options to accurately executing a range of different financial transactions. This type of testing is further complicated by the myriad of third-party payment processes that mobile application owners depend on to support a high-quality end-user experience. 

Additional examples of payments testing test cases include:

• Know-your-customer and payment flows
• On-location payment terminal systems
• Currency-specific credit cards
• Cryptocurrency and alternative payment methods

8. Usability Testing

Usability testing is a mobile app test that evaluates the ease of use and intuitiveness of a mobile application. Some of the most functionally sound applications still fail to gain adoption because the experience does not match user expectations. Through hands-on, highly interactive sessions with representative groups of real end users, usability testing informs how users feel about the application experience.

Led by trained UX researchers, usability testing studies uncover a range of insights that inform how well an application experience delivers against end users’ expectations. Usability testing projects include: 

• Preference testing
• Design testing
• Moderated usability testing
• Unmoderated usability testing
• Competitive experience testing

9. API Testing

API (Application Programming Interface) testing evaluates whether an app can securely, consistently, and efficiently communicate with externalized services. It tests the functionality, performance, reliability, and security of the APIs that mobile apps rely upon to deliver a seamless end-user experience.

API testing serves as a complement to functional testing by decoupling testing from the user interface of the application. This form of testing seeks to uncover if API calls return the appropriate data, in the appropriate form, within a given time SLA. Product teams can gain quality assurance efficiencies through API testing because it removes a dependency on the release frequency of the application front end. 

API testing enables organizations to achieve several key benefits, including:

• Functional validation: Ensure that API endpoints provide the right outcomes and perform the expected functions
• Data accuracy and integrity: Ensure that the data returned by API responses is accurate and consistent with what’s stored in the database
• Error handling: Test how well the API handles different error scenarios
• Performance and scalability: Evaluate the response time of API calls under varying loads to ensure the API meets performance and scalability requirements

10. Build Testing

Build testing is a pre-release mobile app testing test that serves as a checkpoint to catch critical issues associated with an updated mobile app build. Build testing is often implemented as a precursor to rolling out a mobile app to the App Store or Google Play. Various testing techniques are applied to conduct build testing, including smoke testing, scripted testing, and exploratory testing solutions. 

Regardless of scope, build testing is a tightly integrated part of a CI/CD pipeline process because it must keep pace with the demands for a speedy and highly interactive software delivery process. 

11. Role Testing

Role testing verifies if different application users can access the experiences and data entitled by their credentials. In some cases, roles such as administrators exist to ensure data access security. In contrast, in other cases, a role may grant a subscriber access to premium features after an upgrade to a paid version of the application.  

Role testing should not only validate application access level but also seek to validate if a change to a user’s role or status results in the correct level of increased or decreased entitlements across the application experience. 

12. Stream Testing 

Stream testing ensures the reliable delivery of audio and video as an interactive part of a mobile app experience. It tests for issues related to live streams and on-demand playbacks, including performance under certain network conditions and intermittent content quality issues that can negatively impact user satisfaction and engagement. 

Stream testing also offers insights into:

• Diagnostics of stream health
• Drops in user impressions
• Content personalization and ad delivery
• Live event monitoring

13. Device Testing

Mobile apps are taking over the world, but they can’t exist without the hardware and operating systems upon which they run. iOS enjoys over 50% market share in the US, but worldwide, Android holds a considerable market share lead at 72.37% vs iOS’s 26.98%.

Mobile device testing ensures a high-quality application experience across the vast array of devices, configurations, and OS versions in your end-user population’s hands and pockets. The continuous expansion of mobile device types (e.g., wearables vs mobile phones) and versions makes this form of testing incredibly challenging. 

Mobile device testing seeks to uncover device, OS, and configuration-based shortcomings in the end-user experience. These include: 

• Are your Android and iOS apps swiping and dragging as expected?
• Does the mobile app switch seamlessly between experiences?
• How well does the screen render across different physical form factors?
• Is the location and biometric-based functionality working correctly?

When testing mobile applications, it’s worth noting that reliance on emulators and simulators alone isn’t enough. While they’re faster and more efficient, they can’t replicate all the diverse real-world and real-time scenarios your app must handle. For this reason, it’s essential to use actual mobile devices to get more accurate testing results.

Related: Top Mobile App Testing Devices and Operating Systems

Automating Testing of Mobile Applications

Successful QA software testing services and teams incorporate test automation into their mobile app testing strategies to improve coverage, enhance release velocity, and free up internal capacity for other strategic priorities. Automated testing helps verify repeated tasks and solid code (e.g., verifying the throughput of an API or scale testing).

As a best practice,  QA teams should use manual testing to conduct exploratory testing that requires human-led insights to identify more nuanced shortcomings of the application experience. Manual testing is also well suited for testing that benefits from real transactions, real data, and real users. 

However, as apps become more complex, test automation is critical to testing faster and extending test coverage on several devices and across test scenarios. Mobile app automation is notoriously complex, so it’s best to avoid automating testing for simple feature releases or updates. In those scenarios, merging manual testing with automation can be helpful. Blending the two together unlocks enhanced optimization and better testing outcomes. 

Ready to take your mobile app testing strategy to the next level? Schedule a demo with a member of our team today to experience our mobile app testing services!