Mobile App Testing: Challenges, Types and Best Practices

November 6, 2018
8 mins read
Last Updated October 12, 2021

Mobile App Testing: Challenges, Types and Best Practices

Users are fickle.

Critical bugs such as crashes, freezing issues, slow load times, unintuitive navigation and privacy breaches may trigger the user to uninstall your app instantly.

Mobile apps are now an integral part of our daily micro-moments, with people spending an average of 3-4 hours per day. Mobiles apps play a key role for everyone in both professional and personal life. And remember, it’s a highly competitive market if your users uninstall your app they have plenty of options to choose from.

While a good reputation precedes you, a bad reputation will follow you for a long time.

Hence, it’s essential to have your applications tested in order to provide the best user experience. Mobiles testing plays a major role in building a mobile app to provide a smooth user experience and functionality.

The Mobile App Testing Pyramid

Anyone who is involved in software testing knows Mike Cohn’s test automation pyramid. The typical pyramid consists of three layers. At the top, there is an automated end-to-end testing layer (including the user interface tests), in the middle of the automated integration testing layer and At the bottom, there is the automated unit-testing layer. Manual testing is not part of the test pyramid, hence it is shown as a cloud for additional testing work. Each layer indicates the number of tests that should be written within each stage and comes with different sizes.

When it comes to mobile app testing, the typical pyramid structure is not applicable to mobile test automation. Unlike, web or desktop applications, mobile apps consists of different devices, sensors and network variations which require a different set of test activities.

mobile app testing

Test pyramid for mobile applications consists of four layers including manual and automated steps. The biggest layer of the pyramid is manual testing and forms the strong foundation for every mobile app project, followed by end-to-end testing, beta testing and a top layer comprising unit testing. Unit tests and end-to-end tests have the same color and represent automation testing while beta tests and manual tests have some color which represents manual testing. The beta-testing layer is new to the pyramid but essential to every mobile app project. Keeping the high expectations of mobile users in mind requires this layer to be part of every mobile project to get early feedback from your mobile customers. You can either use a crowd testing approach for your beta testing or you can ask your colleagues to beta test early versions of your app to provide important feedback.

Unlike web applications, not every unit of mobile apps can be tested in an isolated manner. In some cases, different APIs, layers or systems may need to be faked or mocked in order to get the small unit to work. This is not efficient from a technical or economic point of view. However, it’s no excuse for not writing mobile unit tests at all. The business logic of an app must be tested at the unit level.

The biggest change in this pyramid is that manual testing is part of it. Mobile testing requires lots of manual testing, and this can’t be replaced by test automation or any other tools yet. The testing team ought to test the various events which may occur when the application is being executed – Incoming calls, SMSs, low battery, alerts such as emails and roaming.

The end to end and unit tests layers can also be swapped as well as the beta and end to end layer. The amount of end to end tests and unit tests can differ from project to project and from app to app.

At the top of the pyramid, there are unit tests. Writing unit tests for mobile apps is not as easy as for backend or web applications. There are so many APIs and sensors that can be used by an app and it is really difficult and time-consuming to mock all those interfaces to write efficient unit tests.

Types of Mobile App Testing

Functional Testing

Functional testing checks whether the functionalities are working as per requirements or not. For example, it tests user interactions with the app such as launching the app, logging in, playing a song, checking an account balance and other straightforward user flows.

Because functional testing interacts with app’s UI elements, database layer, network layer and more it is generally a time consuming and complex process. You would require a good balance of different functional testing types to get the most out of it.

Regression Testing

As the name indicates, regression testing checks whether new feature updates, patches or configuration changes hadn’t brought new regressions, or bugs, in both the functional and non-functional areas of a mobile application system. Regression testing confirms that any changes which are made by the development that is walking through to the improvement.

For example, many software as a service (SaaS) providers will regularly update their features or add new functionality to their offerings with each software update. To ensure their core product remains unaffected by new feature additions, these companies will perform regression testing.

Performance Testing

Mobile app Performance testing is the process of determining how a system responds under a particular workload or task. In general, performance testing tests the speed, stability, and scalability of an application. It is performed on both the client side and server side.

On the server side, it checks variations in response times, streaming resource intensive packets, delays in delivery of messages, application crashes, etc.

On the client side, it checks the usual discrepancy of application behavior on various platforms and handsets, memory and CPU consumption, loading speed and battery issues.

Security testing

Security can be business critical—for example, when attackers steal customers’ data—thus making it a very important part of the development and testing process of the mobile app. Mobile application security testing is a complex topic that requires knowledge in many different areas, such as client-server communication, software architecture, and system architecture. Because of its complex nature and the specialized skill set required, security testing is best done by experts. It includes methods such as manual or automated penetration testing with man-in-the-middle attacks, fuzzing, scanning, and auditing the software.

Penetration testing is an approach used to find security weaknesses in an application that allow access to its features and data. There are several open-source and enterprise tools on the market that can test the application for common vulnerabilities. A list of common security testing tools can be found on the OWASP (Open Web Application Security Project) page.

Usability testing

In usability testing, real users check the features and functionality of the mobile app. The primary focus of this testing is on easy and quick use of an app, simple onboarding and user’s satisfaction with the entire experience.

Users are given tasks in a test environment and encouraged to think aloud while trying to accomplish the tasks. They check different habits of the users such as attitudinal, preferential and situational to improve app’s user experience.

Compatibility testing

Due to the diversity of mobile devices and platforms, compatibility testing for mobile apps is indispensable. Compatibility testing is performed to check the application behaves as expected across the combination of mobile devices and browsers.

The following practices in compatibility testing help covering a maximum number of devices.

Create the Device Compatibility Library: Take every device or model available in the market and structure the information of platform details, technology features supported by the device (audio/video formats, image, and document formats, etc.), hardware features included in the device, and network and other technology features supported by the device.

To cover maximum users in the region, shortlist the device list based in compliance with the region or country’s peculiarities.

Divide all devices into two lists: fully compatible vs. partially compatible devices. Fully compatible devices support all technology features required to make all the application functionalities work seamlessly, while partially compatible devices may not support one or a few features and therefore cause error messages.

End to End testing

End-to-End Testing is a methodology used to test whether the flow of an application is performing as designed from start to finish. The purpose of carrying out end-to-end tests is to identify system dependencies and to ensure that the right information is passed between various system components and systems. The entire application is tested in a real-world scenario such as communicating with the database, network, hardware, and other applications.

User Acceptance Testing(UAT)

User acceptance testing (UAT) also known as beta testing is performed by real users and often used as a final checkpoint before the product release. It allows users to test your app and verify whether it is user-friendly, operates as expected, and can handle tasks in real-world conditions (or not). Generally, during UAT, project managers, developers, QA team and stakeholder are available for the final check.

Mobile App Testing Checklist

This checklist is specifically designed to test the characteristics of a mobile app.

It includes general mobile app testing scenarios for performance testing, usability testing, security testing and other testing activities necessary for your specific app.

The checklist is divided into five different categories:

  • Device specific characteristics. These are characteristics that are related to the device on which the app is installed.
  • Network specific checks
  • App checks. These are things to check that have to do with functionality that is frequently used in an app.
  • App User interface checks.
  • Store specific checks. The checks don’t have to be executed in the order they are given.
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Mobile Automation Testing

Mobile test automation offers the possibility to test mobile apps instantly and effectively with higher test coverage. Once tests have been automated, they can be executed quickly and repeatedly, again and again. In almost all cases, itis the most cost-effective method for software products that have a long maintenance life. The true benefit of automation comes not only from the repeatability of tests but also from the ability to execute tests that probably could not even be performed manually.

Since most of the companies follow agile development practice, mobile app automation testing fits well agile process. Test automation offers a significant value-add by enabling testing to be done in parallel — for example, as nightly test sessions. By the next morning, the tests will have been finalized and the results of the latest regression will be ready for review. Fixing an issue earlier will save a lot of time and get developers to finalize the product sooner; most importantly, it cumulates to better quality, with fewer bugs.

In a nutshell, mobile automation testing is a solution to a common problem: how to produce high-quality, robust and reliable software with the ever-growing complexity of technology and under massive competitive pressure. Automated testing improves business results in three ways: greater testing efficiency, greater testing effectiveness and a shorter time to market.

mobile app testing

Mobile Automation Testing Tools

With the aim to meet the demands of an agile development process, there are plenty of mobile automation testing tools which can help the team to test varied parameters of the mobile apps like behavior, performance, security, etc. in the completely automated way. Some of these testing tools work competitively on native, hybrid and web applications.

Automation testing is the best way to increase the effectiveness, efficiency, and test coverage. The true benefit from test automation comes from the repeatable nature of those tests, but also from test execution that probably could not even perform manually.

Selection Criteria to choose the right mobile testing tool

  • Cross-team collaboration capabilities (Both QA and Dev can easily use the same tools)
  • Always perform tool feasibility since mobile technologies and platforms are varied.
  • Select tools that support both platform simulators and devices, because you can mix and match devices and simulators to optimize runs on different platforms.
  • Look for automation in non-functional areas like an interruption, hardware scenarios like battery state changes, etc.
  • Always optimize on the platform support, in some cases, there could be a need for one or more tools to perform automation.
  • Look for multiple devices support and versions support.
  • Look for utility and reusable functions that would add value to automation.
  • Integrated execution with a test management tool is going to be important for tool success.
  • Look for data-driven automation support as iterations in execution is going to increase coverage and ROI.

Mobile App Testing using Emulators, Simulators and Real Devices

There are different strategies for mobile testing, but when it comes to simulators/ emulators and real devices, it’s not really an either/or approach. Each solution has its benefits and drawbacks, depending on the stage of an app’s lifecycle. Let’s see where and when to use emulators, simulators or real devices.


An emulator works like the real device and duplicates every aspect of the original device’s structure, both software, and hardware. It basically simulates all of the hardware the real device uses, allowing the exact same app to run on it unmodified, and all of the software. The main advantages of emulators are that they are open source and hence cost effective.

There are some disadvantages like they are very slow. Also, a mobile device emulator doesn’t take into consideration factors like battery overheating/drainage or conflicts with other (default) apps.


On the other hand, simulator sets up a similar safe environment to the original real-life device’s OS, but it doesn’t attempt to simulate the real device’s hardware. So what you will see is the OS and the interface of the device you want to use, but you won’t experience all the problems the hardware might cause. Some apps may run a little differently and that’s the main reason why simulators aren’t very reliable.

Real devices

Simulators and automated tests that predict the performance of hardware, but running tests on these simulators is not as reliable as tests conducted on a physical device. A simulator also can’t account for some hardware features – such as specific chip settings, processing power, and device memory. It requires real devices for complete hardware and software testing.

Device testing on a cloud platform

For mobile app developers and testers, delivering high-quality apps across all of the different device and OS combinations is a major effort – it’s time consuming, complicated, and expensive. And, as new devices continue to enter the market, developers are looking for an easier way to build and test across them.

Cloud device testing allows developers to upload their apps and test them on “the most commonly used mobile devices across a continually expanding fleet that includes the latest device/OS combination. 

Challenges in Mobile App Testing

Device fragmentation

Mobile applications must provide a seamless experience across a wide range of devices and OS versions. QA engineers should be highly responsive to any changes to the hardware and software which may create issues for their users. Teams must account for everything from network carrier settings to battery charge levels. Fragmentation is particularly a challenge when some mobile users continue to use older versions of an OS or device even after new ones are introduced.

Testing every combination of device, OS and network settings creates a large number of test cases. This requires development teams to perform the work of sourcing and maintaining a growing pool of mobile devices. These challenges represent major roadblocks for mobile app developers.

Multiple data connections

Most of the apps use mobile data connections (Edge, UMTS, 3G, 4G) and wifi (b, g, n). When users move around there’s a possibility that their connection type will change. Unfortunately, some carriers filter the web on their own will, which results in the devices being connected without actually having a connection with a specific service (messaging or calling through apps). The real world environment can’t be replicated and issues may occur even if connection API’s on mobile platforms have been developed. It’s important for the QA team to test the bandwidth usage as not many carriers support unlimited data volumes.

Application complexity and third-party integrations

Many mobile applications require third-party integrations for analytics, crash reporting, SMS service. For the seamless user experience and functionality, these applications rely heavily on third-party integrations or hardware components. This makes test teams switch between multiple personas (or devices) throughout the course of the test scenario. These complex use cases inflate the amount of work required to adequately test the application.

Processing power and battery life

Mobile applications which include gaming or video streaming component can drain battery life very quickly. Users run lots of apps during the day and several processes are running on the background without even noticing us. This all requires CPU cycles which consume power and thus the batteries tend to dry. A dedicated mobile device lab is used to understand the impact of iterations in a mobile application. It matches any new code submitted by engineers and analyses any negative impact on how the app utilizes phone memory, how fast users can scroll through a feed, and battery consumption.


The mobile app ecosystem is one of the biggest industry now. Due to the highly competitive market, it’s obligatory to maintain an excellent quality of any kind of mobile application. Just a few clicks and swipes are enough for a user to praise or abandon an app.

For your business to be successful, it is extremely important to create a bug-free and user-friendly mobile app. At Simform, we offer mobile testing services supported by our proven and industry-recognized testing approach to our clients.

Working from last 8 years into consumer and enterprise mobility, Hardik leads large scale mobility programs covering platforms, solutions, governance, standardization and best practices.

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