What is Web Performance Testing and Why do You Need It?

Performance testing is one of the most challenging components of web application testing. Irrelevant web performance test data or wrong metrics, chosen during testing, cost companies a ton of money and effort.

If done right, performance testing has all the tools needed to forecast product behavior and its response to user’s actions with an impressive amount of detail and precision.

In this post, you will get to know the plethora of performance testing types, find out what the best practices in the field are, and will be able to make an informed choice whether to hire testing specialists or run testing sessions on your own. 

Table of Contents

  1. Types of Web Performance Testing
  2. The Objectives of Web Performance Test
  3. Step by Step Guide on How to do PT
  4. Performance Testing Tools for Web Applications
  5. Summary

Types of Web Performance Testing

Performance testing encompasses a wide range of metrics and characteristics — QA professionals assess response time, resource utilization, system throughput, and so on. Grouping testing activities into types by nature helps project teams ensure they don’t skip a single crucial testing aspect. Below are the main types of web application performance testing:

1. Performance testing

Developers do performance testing for web application projects to assess the overall speed, stability, and scalability of the project. Project teams implement performance testing to ensure the final build meets the expectations of an end user and helps a business achieve its objectives. 

As a result of a testing session, companies might end up with a list of mismatches between expected and actual performance. Having a deeper insight into the weaker point of an app helps during fine-tuning and brings more substance to the decision-making process. 

2. Load testing

To conduct load testing, a team needs to estimate the user load an online application will be subjected to once released. Then, an estimated load is simulated to test the system response. 

Through load testing, business managers can pinpoint and fix concurrency issues, ensure they have enough server power and bandwidth to support an estimated load. This type of testing is a must-have for scalability planning. 

3. Stress testing

Stress testing helps teams define issues that only become visible under peak load conditions. During this type of system validation, QA specialists simulate loads that exceed reasonable estimates to test the performance of web application. 

Product owners should keep in mind that product may crash and this is a normal situation — yet, it’s crucial to ensure that no data is lost during the shutdown and no security exploits are out in the open. 

Stress testing prepares the maintenance team for extreme situations and helps establish triggers of system shutdown for proactive management. 

4. Capacity testing

Capacity testing lays the groundwork of successful capacity planning — it helps determine how many concurrent operations the system is capable of handling. As a result of such testing, developers will know how to react once the amount of data, processed by a system, as well as the user load increases. Thanks to capacity testing, system admins will know what server capacity, bandwidth, etc. are needed for high-quality, error-free product performance. 

5. Component testing

Any kind of web performance testing can be handled as component testing. It’s an approach that aims at the system’s architectural components. Networks, servers, databases, storage devices, firewalls are all examples of these components. 

6. Smoke testing

A smoke test is the first run through a developed application that helps determine its weakest points and most pressing issues. Smoke tests are usually performed under normal production conditions, with an estimated user load and data volume. 

7. Unit testing

Unit testing refers to validating the smallest subsets of a system — functions, classes, methods, objects, and so on. Running unit tests doesn’t require a separate testing team — typically, they are performed directly by developers who write the code. Unit testing is a way to smoothly incorporate the validation of system performance into the development cycle.

8. Investigation

To determine the root-cause of the problem, a team needs to run investigations — gather performance-related data. All the insights, collected during the investigation, help testers back up or disprove a hypothesis regarding a cause or a solution to a performance issue. 

9. Validation 

Validation tests determine if a system matches a set of business requirements and expectations. Developers usually validate the following characteristics of the project:

  • Speed
  • Stability
  • Scalability

The Objectives of Web Performance Test

Performance testing is a way for companies to be proactive, detecting and neutralizing potential risks before bringing the product to the market.

Failing to validate the system properly usually results in high opportunity cost, reputation losses, low conversion, and user satisfaction rates. 

Namely, project teams conduct performance testing for the following reasons:

  • Detecting system bottlenecks. Testers can analyze the product under different conditions — change user loads, data volumes, access the WPA from a range of locations. After careful observation, a team will easily pinpoint performance issues and brainstorm the cost-efficient ways to handle these problems before rolling out the product on the market. 
  • Ensuring that the project is stable across different operating systems. Performance testing helps ensure that users can access a designated number of features on all supported platforms. This way, business managers protect themselves from the risk of losing potential leads due to the poor support of one or several operating systems.
  • Ensuring that there’s no product degradation since the last release. Performance testing of web applications after any major code change is crucial — this way, business managers will be able to ensure the quality of the system’s performance hasn’t dropped. 
  • Checking if the product complies with SLAs, contracts, and current regulations. The data that’s obtained as the outcome of performance testing is essential for project stakeholders — based on the insights, they can assess the development team and determine whether a product is ready to be brought to the market. 
  • Finding the ideal configuration for an app in terms of throughput, components utilization, and response time. Performance testing helps predict how many system resources are needed to maintain web application. After the testing stage is complete, the project team will be able to create a configuration that delivers a high-quality performance without compromising business objectives. 
  • Reducing downtime-induced revenue losses. By being able to pinpoint the warning signs of possible system shutdown and fine-tune the web application, a company manager can reduce the risks of downtime, as well as reputation and financial losses it brings. 
  • Improving the quality of scalability strategies. Knowing the system’s capacity and being able to estimate resource usage increases business owner’s awareness of a budget, the team size, and effort scalability requires. Performance testing promotes responsible scaling and helps managers synchronize the activities of marketing and development teams. 

Step by Step Guide on How to do PT

Web app performance testing is so diverse and dependent on a set of objectives set by each business manager that developing a single, unified guide that fits web-application testing across all domains is nearly impossible. 

Nevertheless, there are common activities and approaches all successful performance tests share. Here’s the list of critical tasks that provide developers, testers, and business managers with the full view of the system. 

1. Set up the test environment

Before writing and running tests, a team needs to create a secure, fully functional environment that would simulate a real-life condition as precisely as possible. Usually, testing environments include:

  • Network configurations
  • Hardware
  • Software tools.

Taking time to establish a functional test environment improves the quality of planning and running tests.

2. Identify performance criteria

First-tier performance criteria that are assessed for all web apps are the response time, throughput, and resource utilization. Depending on business requirements, additional metrics might be measured and captured. 

3. Plan tests

Thorough research is a cornerstone of an intelligent test plan. A testing team needs to gather the most likely scenarios and ways for users to interact with the system. After testers have collected a range of cases, they need to come up with ways to simulate needed interactions. QA specialists also define metrics that will be captured during the testing. 

4. Configure the environment

At this stage, a QA team creates a toolkit of load-generation and performance-monitoring tools. Also, testers create a bank of IP addresses to use during sessions. As project testing moves along, it’s a common practice to modify or expand the web server performance testing toolkit to provide a broader view of the web application’s performance. 

5. Execute tests

The success of test execution heavily depends on the way your team has handled all the previous steps. Other than that, here are the practices to follow as you execute performance tests:

  • Assign a person responsible for monitoring;
  • Have a habit of regularly validating test data, systems, and scripts involved;
  • Review all test results to ensure there were no flaws in the process;
  • Keep logs of all tests in case you need to re-iterate them later during the application life cycle;
  • Execute smoke tests before moving to the real ones; 
  • As a rule of thumb, QA professionals usually execute each test three times. 
6. Analyze and compose results

Keep in mind that the outcome of performance testing may have answered the developer’s questions regarding the system’s behavior. Stakeholders, on the other hand, will not be satisfied with a full technical report. What they need is an explanation of how the testing outcome translates into business needs. 

When sharing test results, offer a condensed range of insights to the team, as well as the raw data to back up the credibility of conclusions a team has reached. If a full test report results in large data volumes, don’t rush to cut it. When attempting data reduction, ensure no valuable insights are lost. 

7. Reiterate

Finally, the results of performance testing are never set in stone. As soon as the code changes, there’s a likelihood response time and other metrics will be affected. That’s why re-iteration is a core part of a successful performance testing strategy. Create a detailed schedule with the re-runs to not forget about re-validating the system. 


Performance Testing Tools for Web Applications

As there’s a variety of testing activities, QA specialists need a broad toolkit for web-application performance testing. From a wide range of tools for this post, we’ve selected five web performance test tools. 

1. Apache Bench

Apache Bench is a simple tool for server-load testing. Testers can run the software from the command line. Apache Bench is a fit for beginner QAs — the only prerequisites for using the system are the command-line interface knowledge, the basic understanding of web servers, as well as a good command of HTTP. 

2. JMeter

JMeter is among powerful load and stress performance testing tools for web applications. It helps testers simulate heavy traffic loads and test the strength of a network or a server. JMeter has a wide range of supported protocols — Web, FTP, LDAP, TCP, Database (JDBC), and many more. There’s a fully functional IDE to give testers as much control over executing and monitoring load tests as possible.

3. Gatling

Gatling is a framework that covers load and performance testing. It is an open-source tool, with a straightforward interface and a range of features that are fully geared towards web applications. 

The range of protocols supported by Gatling includes HTTP, Server-sent events, WebSockets, JMS, AMQP, MQTT, and ZeroMQ. Along with HTML-rich reporting and a built-in DSL, Gatling provides testers with a wide range of plugins — testers can extend the tool’s functionality in a way that benefits the testing framework. 

4. BlazeMeter

BlazeMeter is a load testing platform that spans websites, web applications, and software. A tool is equipped with a range of plugins — there’s a Jenkins CI module, a dedicated Drupal module, and an integration with JMeter. 

BlazeMeter is one of the most functional load testing tools that took the entire process to the cloud. 

5. Loadrunner

Loadrunner is an application testing tool that helps analyze system behavior and adds to the efficiency of load testing. It allows QA professionals to run automated tests as they can store all simulated interactions as scripts and use them for future testing.

Loadrunner-simulated activities include keypresses or mouse clicks. The tool supports application, database, network, and server testing. Internetworking, email protocols, as well as remote client technologies, are supported. 


Performance testing offers business managers a pool of insights, provides data for efficient decision-making and minimizes the number of risks the team may encounter after the product release. Skipping crucial steps or stages of the process, on the other hand, can mislead stakeholders and greatly overestimate the performance of the product. 

For a performance testing service, be sure to hire a skilled and experienced team. Performance Lab has certified testers on board that have handled projects with multi-layered infrastructures across challenging domains — finance and banking, healthcare, etc. Take a look at our portfolio to see the living proof of our team’s expertise. To get a skilled team of testers to work on your project, contact us!

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