What is Mobile App Testing? Definition, Types & Best Practices

Every app you ship is a promise to your users that it will work. Mobile app testing is how you keep it.

Types of Mobile Apps

Mobile apps come in three types:

• Native apps — These are built specifically for one platform, either Android or iOS. They work best on their intended platform but cannot run on the other.
• Web apps — Web apps are websites that you open in a mobile browser and do not need to be downloaded or installed.
• Hybrid apps — Hybrid apps integrate elements of native and web apps. They work across different platforms and are easier to maintain because developers write the code once and use it everywhere.

Testing is not a one-size-fits-all process, especially when comparing web vs hybrid vs native apps.

Mobile App Testing vs. Web App Testing

Mobile and web app testing share the same goal but differ significantly in scope and complexity.

Difference between Emulator, Simulator, and Real Device

Let's take a closer look at the difference between emulator, simulator, and real device for mobile app testing to gain a better understanding.

Emulator-based app testing

A mobile app emulator is a virtual platform that duplicates an Android handset on your computer, making mobile software testing easier. As a result, you can test Android apk files without a physical device by using an online APK emulator.

Simulator-based app testing

A simulator is a virtual platform that emulates the iOS operating system and executes the program on the specified Apple device (e.g., iPhone app emulator) by taking over the computer's operating system without the requirement for a physical device. Utilizing a simulator helps you to execute iOS app testing quickly.

Real device-based app testing

It is critical to test a website on various devices to ensure that it is compatible with multiple screen sizes, resolutions, operating systems, and browsers. Testing on real devices allows testers to find issues that may otherwise go undetected when testing on emulators or virtual computers

In the next section of the mobile app testing tutorial, we will discuss different approaches to mobile app testing.

7 Parameters for Mobile App Testing

Choose between virtual and real devices based on what you need to validate.

User interface

If you only need to validate layout and basic visuals, a virtual testing platform is usually enough.

Network condition

Virtual platforms can simulate bandwidth limits, but they do not fully reflect real-world latency and hardware behavior. For realistic network testing, real devices are the better choice.

Sensors

Emulators can help early on, but sensor behavior should be validated on real devices to confirm accurate responses.

Performance

Virtual testing can cover basic load checks, but accurate performance analysis often requires real devices, especially for offline behavior and real network conditions.

Cost

Real devices are more expensive, while emulators are often free or low-cost. The tradeoff is lower realism.

Maintenance

Virtual platforms are easier to maintain. Real devices require procurement, upkeep, and ongoing operational cost.

CPU usage and battery

Battery and CPU usage are best measured on real devices, where background processes, heat, RAM, and GPU usage affect actual performance.

5 Benefits of Mobile App Testing

Before you start mobile app testing, it’s important to understand why it matters. Here are the key benefits that make it essential in the development process:

1. Ensure User Interface (UI)/ User Experience (UX) Usability

App testing allows the mobile testers to test applications according to the end-user perspective. They check the mobile app's usability and user-friendliness by simulating typical users' behavior and testing their look and feel. Testers identify any navigation issues and logical flow and test mobile apps on different devices and screen sizes by performing mobile app testing. This helps to evaluate the UI/UX usability of the mobile app.

2. Ensure proper functioning

Mobile app testing allows checking mobile app performance and functions without any errors, issues, or glitches. For example, testers can find out whether users can successfully download the app to multiple devices. Or whether the mobile app interacts with supported infrastructure. Hence, you can verify the seamless functioning of the mobile app with mobile app testing.

3. High end-user loyalty

When you get assured of mobile apps' usability, functioning, and performance, it tends to provide a positive end-user experience. End-users are more likely to use the app and recommend it to their friend leading to a good reputation and high revenues in the software industry.

4. Identify security vulnerabilities

Mobile app testing is also performed to verify and check any security vulnerabilities in the mobile apps, like data leaks or unauthorized access. Thus, one of the major benefits of app testing is to prevent any potential data breaches and security-related issues.

5. Lower mobile app development cost

You can easily and early identify errors or bugs in the mobile app during its development process. This further ensures that they are fixed at an early stage and prevents the high cost of fixing bugs later.

In the next section of the mobile app testing tutorial, we will discuss different mobile app testing types.

Challenges of Mobile App Testing

Mobile app testing is not an easy task. Testing apps on all platforms takes a significant amount of time and work.

This section of the mobile app testing tutorial focuses on the challenges that testers might face during mobile app testing.

• Device fragmentation is one of the most significant app testing challenges since the number of active devices running an app at any given time grows yearly.
• Businesses all across the world create smartphones with varied screen sizes. To appeal to a wider spectrum of customers, multiple variants of the same model have varied resolutions and screen sizes. As a result, apps must be built in tandem with each new screen specification given to the market.
• Testing mobile network bandwidth is an important component of mobile app testing. End users expect fast mobile apps, which the backend team must deliver. But there's more. An app that struggles to provide faster results also struggles with data transfer.

If you are looking for a list of all possible challenges and solutions for those, you can go through our earlier mobile app testing tutorial on mobile app testing challenges.

In the next section of the mobile app testing tutorial, we will learn some of the best practices for mobile app testing.

Types of Mobile App Testing

Mobile apps must be tested across multiple dimensions to ensure they work correctly for every user, on every device, under every condition. Here are the core types of mobile app testing you should include in your strategy.

1. Functional Testing verifies that every feature in the app works as intended. This includes user interactions, navigation flows, form inputs, API responses, and data processing. If the app does what it is supposed to do, it passes functional testing.

2. Performance Testing assesses how the app behaves under normal and peak conditions. It measures load time, responsiveness, stability under heavy usage, and behavior when device resources like memory and CPU are constrained.

3. Compatibility Testing confirms that the app works consistently across different devices, screen sizes, OS versions, and hardware configurations. A feature that works on a Samsung Galaxy S24 must work the same way on a budget Android device running an older OS.

4. Security Testing identifies vulnerabilities that could expose user data or allow unauthorized access. This covers data encryption, session management, API security, and compliance with data protection regulations like GDPR and HIPAA.

5. Usability Testing evaluates whether the app is intuitive and easy to use from the end user's perspective. It covers navigation logic, accessibility, gesture support, and the overall user experience across different screen sizes.

6. Interrupt Testing tests how the app handles unexpected interruptions mid-session, including incoming calls, push notifications, SMS alerts, app backgrounding, and low battery warnings. An app that loses user state or crashes on resume will generate negative reviews regardless of how well its core features work.

7. Network Condition Testing validates app behavior across different connectivity scenarios including 5G, 4G, 3G, public WiFi, and offline mode. An app that performs well on broadband in an office must also handle a slow 3G connection and a dropped network gracefully. TestMu AI's Real Device Cloud lets you run network condition tests on real devices across actual network environments.

8. Localization Testing ensures the app functions correctly when adapted for different languages, regions, and cultural preferences. This includes text rendering, date and currency formats, right-to-left language support, and locale-specific content.

9. Regression Testing verifies that new code changes or updates have not broken existing functionality. Every release cycle introduces risk to previously working features. Regression testing catches those regressions before they reach users.

How to perform Mobile App Testing?

To perform accurate and robust testing of mobile applications, it is important to perform end-to-end testing. It ensures the seamless functioning of mobile apps.

This section of the mobile app testing tutorial discusses the steps to perform mobile application testing:

Step 1: Create test plan

Firstly, you should prepare a clear outline of the test to be executed for mobile apps. Try to include all the test plans and utilize cases in the list. Following this, decide on the test briefly that you want to perform with the expected outcome for the sprint.

Step 2: Choosing test type

Now you have a test plan, and you have to choose the type of mobile testing approach you intend to perform. For example, whether you want to test the mobile app manually or automate it. However, choosing the testing type, you have to focus on certain factors. For example, in this section of the mobile app testing tutorial, we have covered a few cases where you should perform automation testing:

• If the test process has the expected outcome: For any type of conditional testing where you are already aware of the outcome, you should choose to perform test automation.
• If the use case is required to be run often: If there is any routine test that has to be run regularly for testing basic mobile app functions, it is better to automate it.
• The mobile devices vary with different screen dimensions and resolutions. To ensure the compatibility of mobile apps, performing manual testing across various devices will be too time-consuming. Hence, automation is suggested.

You should remember that testing small components of mobile apps is more efficient and manageable when automated. However, always prefer performing manual testing when you have to test the system repeatedly.

Step 3: Preparing test cases

When you have decided on the type of mobile testing, you now have to create test cases to execute the test. In this step of the mobile app testing tutorial, you must select the appropriate approach, like requirement-based testing and business scenario-based testing.

The type of test cases you define depends on the test you will perform. To this, there are two broad categories of testing that mobile apps undergo, which include:

• Functional testing: It includes unit testing, system testing, acceptance testing, regression testing, etc.
• Non-functional testing: It includes security testing, volume testing, performance testing, load testing, compliance testing, etc.

Step 4: Manual testing

When you choose an Agile testing framework, it is always advised to use both manual and automation testing approaches to perform effective testing. However, when you start to test mobile apps, the testing sprint should always begin with exploratory testing.

Since it does not require any initial investment, it is always preferred at the first stage. To maintain a record of the test, you should keep logs of the entire testing session in an Excel or Word document.

Manual testing can be done in two different ways:

• Testing on emulators or simulators: They are the tools to mimic real mobile devices and run them on your computer system to perform the test.
• Testing on real devices: Real devices are physical hardware components used for testing software applications or systems. A real device is anything physical, such as a smartphone, tablet, laptop, desktop computer, server, or anything else wired into the Internet.

Step 5: Automated testing

Testing is an exhaustive process and requires verifying each functionality of the mobile app, depending just on manual testing can be time-consuming. Therefore, for the regular and expected tests, it is recommended to automate the test.

Automation testing saves time and human effort. Further, testers mainly perform automation testing for load testing, performance testing, spike testing, and stress testing. You should be particular in choosing the right automation tools as per your test requirement (discussed in the above section of the mobile app testing tutorial).

Step 6: Usability & Beta testing

Usability and beta testing are crucial parts of mobile app tests in unmasking hidden and critical errors before their release in the market. You can initiate usability testing during the design phase to get feedback from real users. It allows developers to exhibit potential features and reduce the list of those users have received perfectly.

Beta testing is conducted when the mobile app is ready, and developers are all set to welcome feedback before releasing it.

Step 7: Performance testing

Performance testing helps determine the mobile app's complete function. Now that you have tested specific features of your application, you are required to test the whole application’s performance. You can quickly identify the scalability, speed, and stability of the mobile app in case there is high traffic from end users. It also checks the mobile app for any system error.

Step 8: Security testing

Before releasing the mobile app in the market, you need to test the security of the mobile app. You must perform security testing and ensure it follows various data security guidelines, such as HIPAA, PCI DSS, and FFIEC. You will be able to analyze the risk associated with viruses, application hackers, and unauthorized access to sensitive data.

Step 9: End-to-End testing

On completion of all intended tests of the mobile apps, developers should finally execute an end-to-end test sprint. It is done to ensure the working of the mobile app as per expectation on the server level and back end. This will give assurance that the mobile app is ready to be uploaded.

In case any issues are found in the mobile app, you can quickly fix them by repeating end-to-end testing. However, if no major bug is found, the mobile app is released to the App stores.

Best Practices for Mobile App Testing

1. Address Device Fragmentation

Testing on a single Android device is insufficient because mobile environments are highly fragmented. To cover the gap:

• Prioritize Platforms: For iOS, focus on the current and previous OS versions. For Android, you must test both high-end flagship devices and budget-friendly “grocery store” models to account for hardware performance differences.
• Use Data: Look at usage metrics to identify which specific devices and OS versions your customers actually use, then prioritize those for testing.

2. Leverage Virtual Testing Tools

You don't need a physical library of every phone. Use developer tools to simulate different environments:

• Simulators & Emulators: Use Android Studio (Android) and Xcode (iOS) to run virtual devices. These are excellent for testing various screen resolutions and OS versions quickly.
• Cloud Device Labs: Platforms like TestMu provide remote access to real physical devices in the cloud, which is more reliable than software emulation for catching hardware-specific bugs.

3. Implement Automation Strategically

Automation should complement manual testing, providing the speed needed for frequent releases without losing the human touch required for UX.

• Frameworks: For teams with deep coding expertise, popular open-source tools include Appium (cross-platform), Espresso (Android-specific), and Maestro.
• AI-native Automation (The Modern Choice): Instead of traditional record-and-playback tools that break with every UI change, use TestMu AI. It allows you to:
  • Automate without code: Create complex test flows across thousands of real devices using AI-driven logic.
  • Self-Healing Tests: Unlike older tools, TestMu AI’s scripts adapt when your app’s UI changes, significantly reducing maintenance time.
  • Unified Testing: Run tests across real iOS and Android devices in the cloud simultaneously.

4. Test Environmental Factors

Mobile apps behave differently based on the user's surroundings. Ensure you test:

• Connectivity: Switch between WiFi, 4G, and 3G to see how the app handles low bandwidth or connection drops.
• Permissions: Verify how the app behaves when users deny or grant permissions (camera, location, etc.).
• Hardware interactions: Test multiple taps, gestures, and how the app handles system interruptions like phone calls.