Top 30 mobile testing interview questions and answers

Introduction

The increasing growth in mobile usage is more rapid than ever before thanks to worldwide digital transformation waves. To serve such rising customer’s demands, most software applications have an equivalent mobile-app version. This accelerating proliferation of mobile applications forces businesses to put more emphasis on mobile testing.

With such significant growth in the mobile industry, there are incredible career opportunities in the mobile testing field. For those preparing to face mobile testing interview questions when applying for a QA job, this list of contents below will set the stage to get you in the groove.

Definition, Types & Functions of Mobile Testing

1) What is mobile application testing?

Mobile application testing means a process in which an application developed for handheld mobile devices is tested to ensure its functionality, usability, and consistency. Testers can perform mobile application testing manually or with automation.

Test Mobile Application Better with Katalon Studio (Free)

2) Why is mobile testing critical for businesses today?

Testing is an indispensable part of every software development process. Mobile application is no exception: the growing number of mobile devices gives rise to a massive operation system fragmentation, screen sizes, and more. That is why tremendous attempts are made by QA teams to ensure the user’s seamless experience across various mobile devices without functionality bugs and issues. By putting the mobile application through rigorous testing, the product team can enhance the app’s ratings, as well as customer satisfaction for valuable referrals for even more downloads.

Moreover, according to the State of Quality Report 2024, mobile automation testing is also experiencing a steady upward trend in the past year. You can download the report to get the latest insights on the industry.

3) What is the key difference between mobile device testing and mobile application testing?

Mobile device testing examines a device’s quality – by validating its hardware and software functions.This process aims to test features, i.e., screen, memory, camera, applications. It also consists of factory testing and certification testing.

Alternatively, mobile application testing means testing the mobile application on different mobile devices to ensure its consistency and functionality. After this process, you can measure the targeted application’s quality, whether it is well-suited for the device in terms of hardware, software, network connectivity, etc.

4) How many types of mobile applications? What are they?

There are three types of mobile applications:

• Native Application        
  A native application is a software application built in a specific programming language for the particular device platform, iOS or Android. It can be easily installed into your devices and available in the application store (Google Play for Android and App Store for iOS), for example, WhatsApp or Facebook.
• Web Application        
  A web application runs inside a mobile web browser, such as Chrome, Firefox, Opera, Safari using a mobile network or WIFI. For instance, some of the web applications are m.facebook.com, m.gmail.com, etc.
• Hybrid Application        
  A hybrid application is a combination of a native app and a web app. Even though this type of application can be installed on a device just like a native app, it is a web app built with HTML, CSS, or JavaScript and runs in a webview.

5) List out the types of mobile app testing

• Usability Testing
• Compatibility Testing
• Interface Testing
• Services Testing
• Low-level resource Testing
• Performance Testing
• Operational Testing
• Installation Testing
• Security Testing

6) What are the common challenges in mobile application testing faced by most testers?

• Executing test cases with various operating systems
• Testing application’s functionalities on a wide range of handsets
• Screen size fragmentation
• Testing applications on different mobile networks
• Different application types (native, hybrid or web app) require different ways to test
• The choice of the right mobile testing tool for QA team

Mobile Testing Planning and Strategy

7) What types of mobile testing should be included in the Android testing strategy?

A standard Android strategy can include these testing types: unit testing, system testing, integration testing, and operation testing subject to the features available of the tested mobile application. Other types of tests would also be performed if required, depending on the application’s features.

8) What is the strategy used to test a new mobile app? Which types of testing should be included?

A comprehensive test strategy should be planned based on specific guidelines to secure an effective performance of a new mobile application. Here are some of the essential points:

• Selection of the devices – Understanding the market’s demand and the commonly used devices will be highly recommended before choosing the set of testing devices. (This choice could be dependent on the stakeholders or the app builders’ consideration)
• Utilizing emulators – The use of emulators is useful, especially in the initial stages of development, since they allow quick checking of the app. It is a system that runs software from one environment to another environment without changing the software itself. It also duplicates the features and works on the real system.
• Types of testing:        
  As for testing a new mobile application, several types of tests should be involved in order to ensure the app works as expected. Therefore, the strategy is all tied into these following types of testing:
  • Functional testing
  • System integration testing
  • Installation and uninstallation of the application
  • HTML control testing
  • Performance testing
  • Testing multiple mobile OS
  • Cross-browser and cross-device testing
  • Gateway testing
  • Network and battery testing

9) What does an automated test plan for Mobile App contain?

Similar to the plan of other application under tests, a plan designed for automated mobile application testing should include:

1. Testing scope and objectives
2. Selected automation tool
3. Required features to be tested:        
   – Performance        
   – Security        
   – Network        
   – Size        
   – Battery memory
4. Test cases
5. Test strategy
6. Person in charge
7. Time frame
8. Resources required

10) List of the best practices for Android Testing

• Developers must prepare the test cases when they are writing the codes simultaneously.
• All of the test cases should be stored and well-documented for reusability.
• Apply continuous integration and execute tests once the code is changed
• Avoid using rooted devices and emulators to achieve the most reliable results

11) While planning to perform an end to end mobile testing, what are the primary criteria you have to consider?

In an end-to-end mobile testing process, QA teams test the entire application from beginning to end to ensure its flow behaves as expected. Throughout these steps, there are some of the many critical requirements to consider:

• Is the application successfully installed across various mobile models, gadgets, and operating systems?
• Does the application launch smoothly with or without a network?
• What are the orientations that the application supports and how do they work?
• Does the application perform well on different kinds of devices and network scenarios?
• How does the application respond when it is used? (i.e. response speed and time)

Performing Mobile Testing

12) What is the difference between simulators and emulators?

Both Emulators and Simulators are virtual devices that are not real phones but have the same functionality as real handsets. The following table shows the significant difference between a simulator and an emulator:

See more on Compare Emulators, Simulators, and Real Devices in Mobile Testing

13) How to test CPU usage on mobile devices?

There are multiple tools available on Google Play or App Store designed for CPU usage testing, such as CPU Monitor, CPU Stats, Usemon, CPU-Z, etc. These are an advanced tool that records historical information about processes running on your device.

14) What are all major networks to be considered while performing application testing?

Performance application testing should cover all of the scenarios on different networks: 4G, 3G, 2G, and WIFI. Although 2G is a slower network, it is better to test on a slower network in order to track the application performance.

15) When performing a sanity test on the mobile application, what criteria should be included?

• Installation and uninstallation of the application
• Performance in different available networks: 2G, 3G, 4G, 5G, or WIFI.
• Functional testing
• Interrupt testing
• Compatibility testing
• Application performance on other handsets
• The behavior of the application when entering invalid credentials

Read more: Smoke Testing vs Sanity Testing: A Comparison

16) What is the best way to test different screen sizes of the devices?

Using emulators is the most effective way in case there are many different screen sizes of devices to test.

17) What are the common bugs that would often be found during the mobile testing process?

In general, some mobile testers classify the most frequently-found bugs into the four types:

• Critical bugs: The device’s operating system crashes when testing the application’s particular feature.
• Block bugs: Unresponsiveness of performance occurs even though the device status is still on.
• Major bugs: A specific feature of the application is unable to perform its functionality.
• Minor bugs: GUI bug is commonly the main case falling into a minor bug list.

Additionally, some other kinds of bugs are also found during the mobile application testing process, for example:

• Slow performance of an application
• Consumption more from the battery by an application
• Completely unresponsive behavior of an app

18) Explain how A/B testing is done for the iOS app?

The A/B testing for iOS can be done through three steps:

• Step 1: Configuring a test that prepares two versions of your iOS application (A&B) with required test metrics
• Step 2: Testing both of the iOS versions above on devices simultaneously
• Step 3: Analyzing the test results to measure and select which will be the better version to release

19) When should a QA team choose manual testing or automation testing for their mobile test projects?

Automation testing has vastly increased testers’ speed and quality in the past decades. Understanding when to make such a transition, from manual testing to automated testing, is the first step to maximizing your team’s efficiency. Here are some of the critical points:

Manual Testing

• The application has new functionality.
• The application requires testing once or twice.

Automate Testing

• The release cycle needs a large amount of regression testing.
• The testing application requires complex scenarios.

Check out this article to choose the right Automation Test Cases.

20) List of the most common problem that testers face while doing mobile testing on Cloud Computing

Executing mobile testing in Cloud Computing poses various challenges for both beginners and advanced testers.

• Subscription model:        
  Even though Cloud solution offers testers a couple of advantages, there is a persistent concern about the subscription model.
• High costs:        
  While Cloud services have been sold as cost-savings solutions, the reality is that these services can be more expensive. The challenge can arise from the cost of the talent needed, the migration process to the team’s mobile testing project.
• Difficulties in mobile automated testing:        
  As for some projects applying automated testing, Cloud computing may come with a pain point for every tester involved. Because mobile automation testing is image-based, executing test cases on Cloud computing would become more challenging and time-consuming. Moreover, automation testing cannot be used outside the framework.

21) What are the essential things to remember while testing apps using the Black Box testing method?

• The application’s compatibility with multiple devices
• The device’s proper connection and disconnection while changing the IP or port address
• The capability to make calls and send messages to other devices
• The compatibility with multiple browsers (Chrome, Firefox, Opera, etc.)

Mobile Testing Frameworks and Tools

22) What is an Android testing framework?

One of the most standard testing frameworks for Android applications is the Android testing framework. It is comprised of three segments:

• Application Package        
  It is the target application that requires to be tested.
• Instrumentation Test Runner        
  This part of the framework serves as a Test Case Runner, allowing test cases to run on the target application. It includes two parts: an SDK tool for building test; and a tool that provides APIs for writing program which controls an Android device or an emulator outside of Android codes (i.e., MonkeyRunner)
• Test Package        
  It consists of two components: Test case classes and Mock objects. Test case classes constitute test methods to perform the on-target application, while mock objects include mock data used as sample input for test cases.

23) What is a Robolectric testing framework?

Testing applying the Android Testing framework with a device or an emulator is challenging. It takes the team’s tremendous development effort and time in building and running tests. And the Robolectric testing framework is considered as a solution to address this challenge.

Robolectric framework allows testers to run Android tests directly on JVM (Java Virtual Machine) without a device or an emulator’s need.

24) What is the latest version of iOS?

The latest version of iOS and iPadOS is 14.0. (This changes quite often, so please check the Apple site for the most recent info)

25) What is the latest version of Android?

The latest version of Android is 12.0. The initial version of Android 12.0 was released on February 18th, 2021 on Google’s Pixel devices. (This changes quite often, so please check the Android site for the most recent info)

26) What is the extension of Android files?

.apk (Android application package)

27) What is the extension of iOS files?

ipa (iOS App Store Package) file is an iOS application archive file that stores an iOS app. Each ipa file includes a binary and can only be installed on an iOS device.

28) Suppose you need to execute a mobile application testing, what would be the technical criteria you will consider while selecting a test automation tool?

When choosing the most appropriate test automation tool, in addition to affordability, it is essential to consider the following technical criteria:

• Multiple platform support
• Application under test
• Script Usability
• Jailbreak Requirement
• Source Code Changes
• Lead time for new OS version

29) How many types of automation testing tools are available for mobile devices?

For mobile testing, there are two types of automation testing tools: object-based or image-based tools.

30) Can you name a few mobile testing tools that are compatible with Android and/or iOS?

Mobile testing tools only used for Android testing:

• Robotium
• UI automator
• Selendroid (Selenium for Android)

Mobile testing tools only used for iOS testing:

• KeepItFunctional
• iOS Driver

Mobile testing tools used for both Android and iOS testing:

• Katalon
• Apptim
• 21
• Kobiton
• Appium
• MonkeyTalk
• Ranorex Studio
• eggPlant

31) List of some iPhone and iPad testing tools

• iPhone tester: Test the web interface on an iPhone’s sized frame
• Appium: Designed as a test automation tool used with native and hybrid ios application
• iPad Peek: Test the web application using an iPad’s interface
• Test Studio: This tool enables you to record, build, and run automated tests for your iPad and iPhone applications.

Ready to Succeed in Your Next Mobile Testing Interview

Mobile testing interview questions can be unlimited regarding the number of items and areas covered. Even though the above answers may not comprehensively be applied in your interview, we hope that those will help you ace a job and grow yourself in the mobile testing journey.

Want to delve deeper into mobile testing beyond interview questions? Check out our FREE Beginner's Guide, packed with comprehensive insights and practical tips for your confident move to the world. 

Should you have any suggestions on this list of interview questions, please feel free to add it here. We look forward to a better and more up-to-date list for all testers. One more thing! Don’t hesitate to get your Free Mobile testing course at Katalon Academy now! In addition to all of this, to better prepare for your interviews, here are some topic-specific lists of interview questions:

• QA Interview Questions
• Web API Testing Interview Questions
• Software Testing Interview Questions
• DevOps Interview Questions
• Manual To Automation Testing Interview Questions
• 15 Questions to Evaluate Your QA Team's Software Testing Process
• Strategies to Deal A Software QA Engineer's Salary