Performance Tests: Preparation, Tools & Practice Tips

Performance testing is one of the most important steps in app and website development. They show how powerful an application is under real conditions and whether it remains stable under heavy loads, many requests or complex processes. If you want to optimally design digital products, there is no way around a structured performance test.

Good technical implementation alone is not enough. It is only through targeted performance tests that it is possible to ensure that users have a smooth, fast and trouble-free experience, regardless of whether they use an app on a smartphone or a website in a browser. The aim is to make performance measurable, to identify weak points at an early stage and to optimize them in a targeted manner.

In this guide, we'll show you what types of performance tests there are, what you should pay attention to, and how to integrate tests into your development process in a meaningful way. Regardless of whether you are planning a new application or want to improve existing systems: Optimum performance determines user satisfaction and the quality of the end product.

What are performance tests?

A performance test checks how well an app or website works under certain conditions. It tests how well the system reacts to various loads, sudden usage spikes or many simultaneous accesses. The task is to realistically record actual performance and ensure that users experience a stable and fast application in all situations.

In psychology, performance tests are often understood as methods for recording cognitive abilities or intelligence tests. In a technical environment, performance testing, on the other hand, involves the systematic analysis of the response time, stability, and scalability of an application. Depending on the goal, different test methods are used to check the individual resilience of servers, databases or interfaces.

This form of testing is an integral part of professional quality assurance and forms the basis for digital products to function reliably even under heavy use.

Why performance testing is important

Performance tests provide valuable insights into the actual performance of digital applications. If pages load too slowly or functions fail under heavy load, user satisfaction drops significantly. In many cases, this results in increased bounce rates and lower conversions, which has a direct impact on business success.

A solid test concept helps to identify performance-related weaknesses at an early stage and to address them in a targeted manner. This ensures that key performance features remain stable under real conditions. Companies can thus operate their systems efficiently and strengthen user trust in the long term.

Performance tests can be carried out using various scenarios, such as concurrent requests, repeated accesses, or limited resources. This targeted determination of system limits also helps to better assess future requirements and plan the infrastructure accordingly.

Comparable to training certain skills in psychology, technical tests are used to build robust systems that react reliably even under heavy use.

Types of Performance Tests: An Overview of Key Tests

Performance tests can be divided into several specialized types of tests. Each of these methods examines a specific service area and provides important insights into the stability and scalability of digital systems. In the following overview, we explain the main types of tests that are used in practice to identify performance bottlenecks early on and address them in a targeted manner. This psychologically oriented structure helps to look at different stress scenarios in a differentiated way and to systematically evaluate them.

load tests

During load testing, the application is tested under realistic conditions. This is about how the system behaves with normal or high user volumes. These tests determine whether performance remains constant even as the number of users increases or whether there are delays. The results are particularly valuable for assessing the suitability of an application for everyday use.

stress testing

Stress tests simulate extreme conditions and deliberately exceed normal usage limits. This determines at what point the application becomes unstable or even fails. It analyses how the system behaves in such a situation, whether it slows down, crashes, or recovers. This type of test is specifically designed to identify critical weak points at an early stage.

scalability testing

Scalability tests focus on the question of how well the system can adapt with increasing workload. If new resources, such as additional servers, are added, performance should improve or at least remain constant. This process is part of the extended field of performance optimization, in which infrastructure and software must work together flexibly.

Continuous tests

Permanent stress can have different effects on a system than short-term spikes. A continuous test checks how the application performs over hours or days while maintaining the same load. The aim is to identify problems such as memory leaks, slow database queries or other physical bottlenecks that only become visible during long-term operation.

Configuration testing

Configuration tests examine how different system environments affect the performance of an application. This involves testing different server settings, database types, or network configurations. The aim is to determine which combination of parameters works optimally and which settings improve or worsen performance. This type of test provides important findings for targeted optimization in operation.

Key Performance Indicators (KPIs): Which aspects are reviewed?

In a performance test, certain key figures play a central role in being able to realistically assess the performance of an application. Response time is one of the most important metrics. It describes how long it takes the system to respond to a user action. Another relevant factor is throughput, i.e. how many transactions the system processes within a specific period of time.

The utilization of resources such as CPU, RAM and databases is also crucial in order to identify potential bottlenecks at an early stage. The error rate shows how stable the system is working under load and how many requests are being successfully processed. Such features enable maximum transparency in the evaluation and provide a well-founded assessment of system stability in everyday life.

How do you conduct performance tests?

Performance testing consists of several clearly defined steps. They are designed to capture the performance of an application as realistically as possible. The structure of the entire process from preparation to evaluation is similar to a well-founded test setup in research, in which every aspect is specifically tested.

Prepare a test environment

During preparation, an environment is set up that corresponds as closely as possible to the later live system. This includes servers, databases, network settings, and real devices. This creates a reliable basis for verifying relevant performance features.

Create test scripts

The next step is to develop test scripts that simulate typical user actions. This can involve registrations, clicks, or form entries. Tools such as JMeter, LoadRunner or Gatling help automate these processes. Comparable to the use of a test subject in a study, here the script takes on the role of the simulated user.

Conduct & monitor tests

The actual execution is carried out by starting the tests while observing all relevant system data. Tools such as New Relic or Datadog provide real-time data on response times, throughput and server utilization. In this way, the first bottlenecks can be identified during the test.

Analyze results

The collected data is checked for bottlenecks, sources of error and deviations from target values. On this basis, concrete measures can be derived to optimize the application in a targeted manner and keep it running efficiently over the long term.

Performance testing tools

Various tools are available for carrying out a comprehensive performance test, which differ depending on the task and system environment.

One proven tool is Apache JMeter, an open-source load simulation program that is particularly suitable for web applications. It measures the speed of response times and helps to identify bottlenecks in server performance.

LoadRunner is often used in larger companies to simulate complex application scenarios under realistic conditions. It allows various user actions to be simulated simultaneously and to precisely track the system response.

Other tools such as Gatling, k6 or BlazeMeter offer similar functions and help teams to realistically test the performance of their applications under heavy load. The selection of the appropriate tool depends on the specific task, the existing infrastructure and the desired level of analysis detail.

Best practices for successful performance testing

Performance tests should be scheduled as early as possible in the development process. In this way, problems with system response or stability can be identified before they have a negative impact on the project budget. Anyone who checks which performance features are critical at an early stage can take targeted countermeasures.

Performance goals should be formulated realistically and tailored to user expectations and business requirements. This includes, for example, how quickly pages load or how many simultaneous requests can be processed.

Even after launch, it makes sense to regularly monitor performance. This makes it possible to identify deteriorations in the behavior of the application over longer periods of time.

A successful performance test requires collaboration between developers, test teams, and project managers. If all parties involved work closely together, bottlenecks can be identified early on and eliminated in a targeted manner.

Conclusion: Specially planned performance tests ensure efficient and stable system performance

Performance testing is one of the basic measures for developing digital applications in a stable, fast and future-proof way. Anyone who tests apps or websites under realistic conditions can see early on whether they can handle the expected user traffic and remain stable under load. A key feature of powerful systems is their ability to respond flexibly to increasing requirements.

Through regular testing, vulnerabilities can be uncovered before they become a problem. An application's capacity to function reliably and efficiently is reflected in its ability to deliver a consistent user experience even under heavy load.

Performance tests provide information about a product's technical competence and help predict how it will perform under various conditions. Anyone who continuously integrates such tests into the development process creates a reliable basis for successfully completing projects and positively influencing the long-term ability of the product to users.