You've spent months building your mobile app. The design looks perfect, the features work brilliantly in your head, and you're ready to launch. Then the reviews start rolling in—crashes on Samsung phones, slow loading times, security warnings, users who can't figure out how to complete basic tasks. Sound familiar? This is the reality for countless app developers who skip proper testing or don't understand what their mobile app actually needs to function properly in the real world.
Testing isn't just about finding bugs—it's about meeting quality standards that users expect and QA requirements that app stores demand. But here's where it gets tricky: there are so many different types of testing that it's easy to get overwhelmed or waste time on the wrong areas. Some developers test everything they can think of; others barely test at all. Both approaches usually end in disaster.
The cost of fixing a bug after launch is typically 5-10 times higher than catching it during development
After working with hundreds of mobile app projects, I've learned that successful apps don't just happen by accident. They're the result of strategic testing that covers the right areas without going overboard. This guide will walk you through each type of testing your mobile app might need—from basic functionality checks to advanced security measures. You'll learn when each type matters, how to prioritise your testing efforts, and most importantly, how to avoid the common mistakes that turn promising apps into one-star disasters. By the end, you'll know exactly what your app needs to meet modern quality standards and keep users happy.
Understanding the Basics of Mobile App Testing
Mobile app testing is basically checking that your app works properly before real people start using it. Think of it like checking your homework before handing it in—you want to catch any mistakes before your teacher sees them! The same goes for apps; you need to find and fix problems before your users discover them.
There are loads of different ways to test an app, and honestly, it can feel a bit overwhelming at first. But here's the thing—you don't need to understand every single type of testing right away. What matters is getting the basics right and building from there.
What Actually Goes Wrong in Apps?
Apps can break in more ways than you might expect. Sometimes buttons don't work when you tap them. Other times the app might crash when you're trying to take a photo or send a message. Your app could work perfectly on one phone but look terrible on another. Or worse—it might accidentally share someone's private information with the wrong person.
These aren't rare problems either; they happen all the time. I've seen apps that work brilliantly in the office but fall apart the moment real users start downloading them. That's why testing isn't just nice to have—it's absolutely necessary.
The Different Types of Testing
Mobile app testing falls into several main categories, each focusing on different aspects of your app. Functional testing makes sure everything works as expected—buttons respond, forms submit properly, and features do what they're supposed to do. Performance testing checks that your app runs smoothly and doesn't drain someone's battery or use too much data.
Then there's security testing to protect user information, usability testing to make sure people can actually figure out how to use your app, and compatibility testing to verify it works across different devices and operating systems. Each type serves a specific purpose, and most apps need a combination of several testing approaches to be truly ready for launch.
Functional Testing—Making Sure Your App Works as Expected
When someone downloads your mobile app, they expect it to work. Simple as that. Functional testing is all about checking that every single feature does what it's supposed to do—buttons respond when tapped, forms submit properly, login screens actually log people in. It's the most straightforward type of testing, but also the most important for your QA requirements.
Think of functional testing as checking all the basic promises your app makes to users. If you have a shopping app, can people add items to their basket? Can they complete checkout? Does the search function return the right results? Each feature needs to be tested individually, then together, to make sure nothing breaks when users combine different actions.
Testing User Flows
The best approach is to map out complete user journeys from start to finish. A new user might register, browse products, add something to their wishlist, then share it with a friend. Each step needs to work perfectly, and the whole sequence needs to flow smoothly without any hiccups or crashes.
Common Functional Issues
The most common problems we see are forms that don't validate properly, buttons that don't respond on first tap, and features that work fine individually but cause problems when used together. These issues might seem small, but they can completely ruin someone's experience with your app.
Start functional testing early in development, not just at the end. Testing each feature as it's built saves time and prevents bigger problems later on.
Quality standards for functional testing should cover every user-facing feature, no matter how basic it seems. Remember, if something doesn't work as expected, users will simply delete your app and find an alternative that does.
Performance Testing—Keeping Your App Fast and Responsive
Nobody likes waiting for an app to load. I can't stress this enough—if your app takes more than three seconds to start up, you'll lose users faster than you can blink. Performance testing is what keeps your app running smoothly, and it's something we take very seriously at Glance.
Performance testing checks how your app behaves under different conditions. Does it work well when hundreds of people use it at once? What happens when someone has a slow internet connection? When comparing performance across different app types, these are the questions we need to answer before your app reaches users' phones.
What We Actually Test For
When we run performance tests, we're looking at several key areas. Load time is the big one—how quickly does your app open and display content? Then there's responsiveness; when someone taps a button, does something happen immediately? We also check memory usage because apps that eat up too much memory get killed by the operating system.
- App startup time and screen loading speeds
- Memory consumption and CPU usage
- Battery drain during normal use
- Network performance on different connection types
- Behaviour under heavy user loads
Real-World Testing Scenarios
We don't just test apps in perfect conditions. Real users have old phones, patchy wifi, and dozens of other apps running in the background. That's why we simulate these real-world situations during testing.
Performance testing isn't glamorous, but it's what separates professional apps from amateur ones. Users might forgive a small bug here and there, but they won't tolerate an app that's slow or crashes when they need it most.
Security Testing—Protecting Your Users' Data
I'll be honest with you—security testing is probably the most overlooked part of mobile app development, yet it's one of the most important. People trust your app with their personal information, passwords, photos, and sometimes even their payment details. Get this wrong and you're not just looking at bad reviews; you're facing potential lawsuits and a damaged reputation that can take years to rebuild.
Security testing goes far beyond just checking if your login screen works. We're talking about testing how your app handles data encryption, whether it's vulnerable to common attacks like SQL injection, and if sensitive information gets stored securely on the device. Your QA requirements need to include penetration testing—where we basically try to break into your app the same way a hacker would.
What Security Testing Actually Covers
The main areas we focus on include authentication (making sure only the right people get in), data transmission (keeping information safe as it travels), and local storage security. We also test for things like session management and whether your app can resist attempts to reverse-engineer it.
Security isn't just about protecting data—it's about protecting your users' trust in your brand
Meeting Industry Quality Standards
Different industries have different security requirements. Banking apps need to meet stricter quality standards than a simple photo-sharing app. But don't think that means you can skip security testing if you're building something "simple"—even basic apps collect user data that needs protecting. For specialised applications, security considerations can be even more complex, requiring additional layers of testing and protection.
Usability Testing—Creating Apps People Actually Want to Use
You can build the most technically perfect app in the world, but if people can't figure out how to use it, you've wasted your time and money. Usability testing is where we find out if real users can actually navigate your app without getting frustrated and deleting it within the first five minutes.
This type of testing involves watching people use your app whilst they complete specific tasks. You're not testing whether the buttons work—that's functional testing. You're testing whether users can find those buttons in the first place and understand what they do.
What Usability Testing Reveals
During usability testing, you'll discover things that will genuinely surprise you. That navigation menu you thought was obvious? Half your testers can't find it. The registration process you designed to be quick? Users are abandoning it halfway through because they don't understand what information you're asking for.
- How long it takes users to complete common tasks
- Where people get confused or stuck
- Which features users ignore completely
- Whether your app's language makes sense to real people
- If the user journey feels natural and logical
Running Effective Usability Tests
Start with a small group of people who match your target audience—you don't need hundreds of participants, just five to ten will reveal most major issues. Give them realistic scenarios rather than step-by-step instructions. Instead of saying "tap the menu button," try "find out how much delivery costs to your postcode."
The key is staying quiet and letting users struggle a bit. Your instinct will be to help them, but their confusion tells you where your app needs improvement. Understanding who your target audience really is will help you recruit the right people for these testing sessions.
Compatibility Testing—Working Across Different Devices and Systems
Right, let's talk about compatibility testing—probably one of the most frustrating parts of mobile app development, but absolutely one you can't skip. Your mobile app needs to work properly across hundreds of different devices, operating system versions, and screen sizes. That's quite a challenge when you think about it.
The Android ecosystem alone has thousands of device variations, whilst iOS has its own complexities with different iPhone and iPad models, plus various iOS versions that users haven't updated yet. Your QA requirements need to account for this massive variety to meet quality standards that keep users happy.
Device Testing Strategy
You can't test on every single device—that would be madness and cost a fortune. Instead, focus on the most popular devices your target audience actually uses. Check your analytics or industry reports to see which devices dominate your market.
Start with the top 10 most popular devices in your target market, then expand your testing coverage based on your app's specific user base and budget.
Here's what you need to test across different devices:
- Screen sizes and resolutions—does everything display correctly?
- Operating system versions—both current and slightly older versions
- Hardware capabilities—camera quality, processing power, memory
- Network conditions—3G, 4G, 5G, and WiFi performance
- Device-specific features—fingerprint sensors, face recognition, stylus support
Testing Tools and Approaches
Physical devices give you the most accurate results, but cloud-based testing platforms can help you test on devices you don't own. Many development teams use a combination of both approaches to balance thoroughness with budget constraints.
Remember, compatibility testing isn't just about making your app work—it's about making sure it works well on every device your users might have. If you find your app consistently crashes on specific devices, there are proven strategies for troubleshooting these issues.
Automated vs Manual Testing—Finding the Right Balance
Right, let's talk about one of the biggest decisions you'll face when testing your mobile app—should you go automated or stick with manual testing? I've worked with teams who swear by one approach and completely dismiss the other, but here's the thing: you need both.
Manual testing is exactly what it sounds like—real people using your app and checking if everything works properly. Think of it as having someone actually tap buttons, swipe screens, and use your app the way your customers would. It's brilliant for catching usability issues and spotting things that just don't feel right.
When Manual Testing Wins
Manual testing shines when you're looking at user experience, visual design, or testing new features for the first time. Humans are great at noticing when something looks wonky or feels awkward to use—things that automated tests might miss completely.
The Power of Automated Testing
Automated testing uses scripts and tools to run tests without human involvement. Once you've set them up, they can run hundreds of tests in minutes. They're perfect for checking the same functionality over and over again—like making sure your login process still works after every update.
- Manual testing catches user experience issues and edge cases
- Automated testing handles repetitive tasks and regression testing
- Manual testing works best for exploratory and usability testing
- Automated testing saves time on functional and performance checks
- Both approaches complement each other rather than compete
The sweet spot? Use automated testing for your core functionality that needs checking repeatedly, and manual testing for new features, user flows, and anything that affects how your app feels to use. Don't make it an either-or decision—your app will be better for having both.
Conclusion
After spending time working through all these different types of testing, you might be wondering which ones you actually need for your mobile app. The truth is, there's no one-size-fits-all answer—it depends on what your app does, who's using it, and what your budget looks like.
What I can tell you from experience is that skipping testing altogether is never a good idea. You don't have to do everything at once, but having some kind of testing strategy will save you headaches down the line. Start with the basics: functional testing to make sure your app works, performance testing so it doesn't crash under pressure, and usability testing to check people can actually use it without getting frustrated.
If your mobile app handles sensitive information—banking details, personal messages, health data—then security testing isn't optional. It's a must. Same goes for compatibility testing if you're targeting a wide range of devices; your app needs to work properly whether someone's using the latest iPhone or an Android phone from three years ago.
The automated versus manual testing debate doesn't need to keep you up at night either. Most apps benefit from a mix of both. Automation handles the repetitive stuff whilst manual testing catches the things that only human eyes can spot.
Getting your QA requirements right and maintaining proper quality standards isn't just about ticking boxes—it's about creating something people will want to keep using. Focus on the testing types that match your app's purpose, and you'll be well on your way to launching something you can be proud of.
