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If your mobile app is slow, it’s doomed to be deserted: a one-second delay in loading leads to a 7% bounce rate. 53% of users leave a website if it takes more than 3 seconds to load. However, users don’t just disappear, but 51% of them leave you for your competitors. That is why performance and load testing is so important to ensure the top-notch performance of your mobile and web app since the very beginning of the development process (just look what Disney Plus suffered recently)

In this article, you will learn about the most common performance problems in mobile apps, performance testing varieties, challenges specific to mobile app performance testing and a sure-fire way to build a successful mobile app performance testing strategy.

The Most Common Mobile App Performance Problems

Many issues can influence mobile app performance. Here are some of the most common ones.


A device is perhaps the most frequently overlooked factor that affects the performance of your mobile app. While some developers build apps for the newest mobile devices, they may ignore the fact that their app won’t function properly on the older ones. If you want to make sure your app will perform well, it’s a good idea to create a list of the target devices. Pay particular attention to phones and tablets with weaker processors and less RAM.


Networking means when and how your application uses the Internet connection. Quite often, networking errors occur when an application sends requests to the server too often and when the data from the server is poorly stored. In this case, we recommend making sure that your app requests data whenever it is necessary and cashes all responses from the server. Also, it is crucial to ensure that your application operates appropriately in the offline mode.

Third-Party Programs

The third reason stems from using external code in your development process. While this approach can streamline application development, you must be very particular about choosing libraries and SDKs provided by third-party vendors.

Mobile App Performance Testing Essentials

Performance testing aims to examine the operability, stability and resource consumption of an application under different usage scenarios and loads. Depending on the area of evaluation, performance testing falls into five varieties:

  • load testing, which aims at checking the performance of an application under the normal user load.
  • stress testing, which aims at evaluating the robustness of an application under extremely heavy load conditions.
  • stability testing, which aims at verifying if an application can perform well for an extremely long period.
  • volume testing, which aims at testing the performance of an application against the “expanded” database.
  • concurrency testing, which aims at determining the number of users who can work with an app simultaneously.

Why Mobile App Performance Testing Is Challenging?

In addition to a couple of well-known common performance and load testing mistakes, the approach of mobile app performance testing differs a lot from that of web applications. For example, while web applications are not affected that much by poor network or device conditions, mobile app performance testing requires paying particular attention to network latency, packet loss, the type of device and so on.

Furthermore, your testing strategy will depend on the type of application.

For example, since web mobile applications can be accessed via a mobile browser, it’s critical to imitate the user load from a browser and to test the web page rendering on different devices. When it comes to native apps, you should pay special attention to testing their performance against the target platforms. In hybrid apps, you need to replicate a user load on the server and test the app against all platforms and devices.

Mobile App Load & Performance Testing Strategy

Whichever type of mobile application your team is developing, there are at least three factors that affect its performance: user behavior, network conditions and the device. To this effect, your QA strategy will consist of four steps:

  1. Creating real-time user scenarios
  2. Creating real-time network conditions
  3. Creating device conditions
  4. Testing your app performance against each component.

Step 1: Create Real-Time User Scenarios

Determine all possible user behavior scenarios and write test cases accordingly. Please note that your test cases will vary according to your app type and the kind of services it delivers. There is a wide variety of possible scenarios, but let’s look at an example.

If your app can be accessed via a desktop and a mobile device, you should create two scripts based on the access type. It is also important to consider the workload pattern for this scenario (for example, 100 users will be using your app via a web browser, 100 — via an iOS app and 100 — via an Android app). On top of that, the geographic location of each user must be taken into account.

Step 2: Create Real-Time Network Conditions

By using automated tools, you should create different network conditions and network quality. 2G, 3G and 4G networks and WiFi connection with high, average and low speed all must be included in your QA checklist. Besides, you should provide network conditions with 50% bandwidth. And don’t forget to test the performance against different locations through emulation.

Step 3: Create Device Conditions

Your application performance might vary depending on different devices. There are two ways to go here: you can run your device through the targeted devices manually or use a real device cloud to be able to test your app against all devices simultaneously.

Step 4: Test Your App Against Each Component

When all the conditions are created, proceed with testing your app against each of them. Here’s what a basic performance testing checklist looks like:

Environment Criteria
  • App launch and installation time
  • Battery consumption when operating
  • Memory consumption against each case
  • Usage with other apps
  • Working in the background
  • Speed of loading content from the server-side against each user case
  • The number of API calls generated from the app
  • How data is handled when the server is down
  • Jitters (how an app handles the data in case of Jitters)
  • Packet loss
  • Performance under varying network speed and latency
  • Performance under varying network connection types

Using Automation Tools for Performance and Load Testing

There are plenty of automation tools available for mobile and web performance and load testing, e.g. JMeter, Locust, etc. But LoadNinja is definitely one of the best on the market.


LoadNinja is a cloud-based load and performance testing platform. Designed for web and mobile web apps, it helps to check how an app and its servers react to a massive load. Here’s a quick guide to load testing with LoadNinja.


  • Platform-independent (runs on any computer with Internet access)
  • Load testing scenarios that simulate user actions with each user working in their own browser (you can combine one or more scripts, specify the number of users, ramp-up parameters, etc.)
  • Test case creation without coding
  • Records user actions in an understandable manner
  • Allows watching virtual user actions in real-time
  • Efficient test management
  • Provides in-depth reports
  • Good for continuous testing with Jenkins


Make sure to invest properly in performance testing. Mind the issues that may arise with devices, networking and third-party programs, create real-time user scenarios and network conditions and device conditions. Automation tools like LoadNinja, JMeter and Locust can help you ensure your app’s performance is stellar. Remember: app performance is one of the most critical indicators that can get your app on the home screen or delete.

Victoria Bezsmolna

Tech Writer