As of 2021, roughly 5.7 million mobile apps are available in app stores — 2.2 million for iOS and 3.48 million for Android users. Given the massive numbers, customers have a wide variety of choices.

With such a high number of apps available, customer satisfaction is paramount, which means avoiding customer churn and retaining users. Is there anything more frustrating than watching your customers switch over to your competitors because they have a stronger, more consistent version of a similar app?

The best way to hold your users’ attention is by giving them an intuitive and highly performant user experience. Performance testing is just one of the useful strategies you can use to get this result.

Mobile app performance testing proactively identifies glitches, bugs, and performance bottlenecks in your app, helping you keep your users satisfied. After all, mobile app users will not hesitate to delete your app if they are unsatisfied with its performance. Effective performance testing before sending your apps to production is crucial to avoid this.

In this article, we will explore the benefits of continuous performance testing for mobile apps, highlight tools for continuous performance testing, and see how you can add performance testing to your CI pipeline.

What is performance testing?

Performance testing is a non-functional testing process that measures how well an app performs under varying workloads. Performance tests analyze system indicators like speed, responsiveness, and stability. With the results of these tests, you can identify and rectify performance-related bottlenecks before releasing the software. These tests examine various indicators like response times, concurrent users, load times, CPU lifespan, and bottlenecks to anticipate the problems a user might experience when using your app.

Without performance testing, users may encounter usability issues or experience inconsistent service. Performance downtime not only leads to lost revenue but can also damage your reputation in the market.

There are several subcategories of tests you can undertake during performance testing. The five major types are:

  • Spike testing — Spike testing determines how your system copes with sudden traffic bursts. Spike testing is done by quickly increasing user-generated volume and measuring the software’s response toward it.
  • Load testing — Load testing evaluates an application under real-life load conditions. The primary aim of load testing is to observe how the app reacts to varying additional loads and the maximum load (number of users) the software can withstand.
  • Volume testing — The chief aim of volume testing is to monitor whether the software can handle large volumes of data in the database. Volume testing helps you identify the breaking point in the system.
  • Stress testing — Stress testing assesses how well the app functions when it is pushed beyond normal usage patterns. It is achieved by loading the software with many concurrent transactions or users and testing its stability.
  • Soak testing — Also known as endurance testing, soak testing tests how well your software and application perform when exposed to high traffic for a long time. It uncovers reliability issues that typically occur after several days or weeks.

Each of these tests enables you to better understand the performability and reliability of the different components of your application. However, running mobile performance tests is quite demanding. This is because testers have to consider the wide range of devices available, each with multiple UI options and varying levels of network connectivity.

Together, these factors make mobile testing complicated. So, to assist with performing these tests, developers often turn to the following tools to conduct performance testing for mobile applications:

  • LoadNinja — LoadNinja is a cloud-based testing tool that runs load and performance tests. This tool lets users use real browsers instead of load emulators. Its easy-to-use interface provides options to analyze in real-time and lower script creation time by 60 percent.
  • Apache JMeter — Apache JMeter is an open source, Java-based testing tool for measuring app performance. Its highly extensible core enables developers to test various use cases. Aside from that, it is also compatible with several networking protocols such as HTTP, HTTPS, POP3, SOAP, LDAP, and FTP Service.
  • WebLOAD — WebLOAD is a popular enterprise-scale testing tool for mobile apps that combines all performance monitoring elements into a single process for easier app testing. With WebLOAD, testers can check for scalability and performance and perform validation tests.

Benefits of performance testing mobile apps

Market saturation and user expectations make high performance non-negotiable if you want your application to succeed in the long run. A mobile app will earn a five-star rating only when it is stable and reliable. By measuring significant attributes of the software usability of your app — such as speed, accuracy, and stability — performance testing ensures that only high-quality applications are pushed to production. By prioritizing user experience, you can help your teams provide customers with a market-ready app that lives up to performance expectations.

For instance, when developers run a load test, they try to understand how an app behaves when exposed to high loads. The test gives them an idea of the traffic load and the max users the app can handle. Similarly, when testers do a performance regression test, it gives them insights into the app’s limitations and provides a realistic view of its speed and accuracy.

Put simply, performance testing exposes an app’s shortcomings before it goes live, enabling you to work proactively and ensure there are no issues or bugs that will impact your app’s overall performance and reputation.

Continuous performance testing in a CI pipeline

The traditional waterfall approach to testing takes weeks to deliver results. It is simply unsuitable to meet the current challenges of fast testing and release that mobile applications — with new versions, updates, and increased integrations — require.

Continuous integration/continuous development (CI/CD) automates the integration and deployment of test builds and ensures that users get the latest tested version of your app as soon as possible. Further, by incorporating performance testing into the CI pipeline, it is possible to know precisely the impact each change has on your app’s performance.

You can implement performance testing into your CI pipeline for functional and non-functional testing indicators like speed, scalability, or responsiveness to ensure that the load patterns are realistic and attuned to real-world conditions.

In continuous performance testing, the tests are broken down into smaller feedback loops so that developers receive test results sooner and can detect and fix bugs faster. Here are the general steps to follow when integrating continuous performance testing into your CI pipeline:

  1. Choose the key performance indicators (KPI) you want to test for. Depending on your goals, your KPIs could be error rate, concurrence, throughput, crashes, load time, and others.
  2. Organize the data and write the performance tests.
  3. Choose an appropriate testbed environment. Ideally, you should choose a cloud-based CI/CD platform to scale tests when needed.
  4. Execute the performance tests in the CI pipeline. We recommend using a CLI for testing; it’s faster and more efficient.
  5. To get faster feedback and optimize your pipelines, you can also run parallel execution of test suites.
  6. When you commit the code, the CI testbed environment will run that code and check if the new code has caused any regressions.
  7. When your system passes the test, it is deployed to production. If it fails, the results are sent back to developers for feedback and review. With the help of powerful analytics features of CI tools, engineers can visualize the problems and do a root cause analysis.
  8. Finally, after the execution is completed, destroy the test environment. This prevents false positives when new tests are run.

Using the steps above, you can continuously test key qualities of your mobile application to ensure it will be highly performant and reliable when it is released to your users. Performance testing becomes more efficient when it is implementeed as part of your CI pipeline.

Additionally, continuous performance testing in a CI pipeline reduces your app’s time to market, enables your teams to resolve issues faster, aids in fixing bugs, prevents outages, lets you perform multiple tests with a range of cases, and helps you compare the performance results of multiple tests.

Conclusion

The worst time to learn that your app has crashed is when it is already in production. Poor app performance leads to customer churn and can impact the long-term future of your application. To keep up with the competition and obtain (and retain) users, try using performance testing, which helps ensure your application is meeting performance expectations.

To your team, performance testing can feel like an extra step that could slow them you down. However, by making continuous performance testing a step in your CI pipeline, you can make your testing process more streamlined and efficient. A streamlined continuous testing process can reduce repetitive manual tasks, freeing devs for other work. Automating tests and the movement of your application’s code through the CI pipeline ensures your team never misses a test.

CircleCI supports highly performant, reliable mobile application development and makes it easy to add performance testing to your CI pipeline. To start delivering fast and reliable mobile app experiences consistently, sign up today.