Why Is Load Testing Important for Web Applications

Software Quality Assurance 28-Feb-2023

In Software Engineering, software testing is a key process of the Software Development Life Cycle (SDLC). A software comprises various components and developers need to account for customer requirements while coding each one of these features.

Due to the complexities of user requirements and the long coding process associated with software development, there is always a possibility that potential bugs may appear in the application. Software testing is necessary for identifying underlying problems and removing them before the software moves into production.

One core process of software testing is load testing and it is responsible for evaluating an application’s response to changing load conditions. Testers conduct load testing by automating the testing procedure and letting multiple simulated users access the application simultaneously.

Load testing is most useful in situations where testers need to evaluate the behavior of websites under a high user load. Since websites and web applications have to constantly cater to thousands of users concurrently, the process of load testing becomes mandatory for them. In this article, we will discuss why load testing is important for web applications.

The Goal of Load Testing for Web App

Like most testing strategies, the goal of load testing for web applications is to expose vulnerabilities. Nevertheless, load testing is a specialized method for detecting issues directly related to user load.

Load testing is slightly different from other testing methods revolving around user load. Techniques such as stress testing evaluate the performance of web apps either in compromised situations or under extreme workloads. However, load testing only relates to the maximum speed and capacity of the web application in perfect working conditions.

This is why many testers rely on load testing to detect significant performance issues such as buffer overflow, memory leaks, and memory mismanagement. At the same time, the testing procedure has the capacity to expose major issues in an applicationlike bandwidth limitation and load balancing problems.

Since we are evaluating the effects of user load on web applications, we can also evaluate other components that link to your web app. Therefore, it is possible to determine the upper limit of all major components in web app such as database, network restrictions, the capacity of servers, etc.

Lastly, load testing can also play a key role in helping companies develop service level agreements for their products. In short, load testing helps us identify the shortcomings of our products and fine-tune the product to improve its performance.

load testing web application

Advantages of Load Testing

Load testing can reap several benefits for your web application. Here are some of the main load testing web app advantages:

Minimizes the Cost of Failure

The cost of identifying performance issues at an early stage is significantly less when compared to later stages. If your web application starts to show its bugs after the launch, it can irreparably damageyour company’s reputation.

You will either have to recall the application and move back to a previous version or halt your web app until all the bugs are fixed. Therefore, the resulting costs are always going to be taxing for your company and damage it severely. Gartner reports that downtime can cost companies as much as $300,000 per hour, on average.

Load testing enables you to detect these problems before your web app goes into a production environment. As a result, it is considerably easier to resolve these issues and you don’t need to pay the costs of post-launch error removal.

Improved Scalability

When software does not handle concurrent users well, it leads to issues such as poor utilization of resources and memory leaks. Load testing enables software teams to find out the limits of their application’s operational capacity. When the team is aware of the system’s limitations, they can easily identify the changes needed to make the product more scalable.

Greater Customers Satisfaction

When a software team evaluates the key issues resulting from increased user loads, they are able to identify problems related to delayed response time and software quality. Since software teams detect these issues before the release of the application, they are able to resolve those issues before production.

In most cases, load testing helps companies eliminate issues such as delayed response times and enhances the quality of the product overall. Therefore, customers can enjoy a greater level of user satisfaction due to load testing.

Minimizes the Risk for System Downtime

Studies show that 59% of Fortune 500 companies suffer from losses worth $46 million each year even if they only have 96 minutes of downtime in a week. Load testing, along with stress testing,enablestesters to simulate real-time app usage under varying loads.

When the system is subjected to increased traffic, it can outline issues that cause downtimes. Therefore, it is easier to resolve problems before they cause downtimes, and the overall likelihood of the system downtime is lower.

Identify Inefficient Code

If your product has a complexly written code, then it will not utilize resources efficiently. However, these problems are hard to detect in normal circumstances and we need load testing to identify these issues.

load testing web applications

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Importance of Web App Load Testing

The usage of the internet in society has grown considerably in the past couple of decades. Statista reports that the world’s current population of active internet users stands at 4.47 billion.With the increasing number of internet users, websites, as well as web applications need to be extremely robust in terms of load balancing and handling high user loads.

At the same time, customers are more sensitive about user experience than they were ever before. Because customers have various options to pick and choose from, they only use web apps and websites that offer them the best experience and results. According to one source, even a one-second delay in response time can decrease user satisfaction by 16%

Load testing is an essential non-functional requirement for web applications.We need load testing to identify whether our web infrastructure is robust enough to handle the expected user load. This is why software testing teams conduct various tests on input/output reads, network throughputs and as well as the utilization of memory and server resources.

Without load testing, there is no way of establishing basic performance metrics and determining the limitations of web applications under changing loads. Besides that, load testing is necessary for detecting and resolving bottlenecks in web applications before it reaches the production environment.

Load testing for web applications essential for creating the ideal user experience (UX), and increasing the quality of the final product. Here are other reasons why load testing is essential for web applications.

Ensuring the Availability of Service

Users from all corners of the world access web applications, 24 hours a day and seven days a week. Therefore, these applications need to be available to all their users without a second of delay. Load testing helps software teams identify issues that can affect the application’s availability. Without it, we can never know for sure if the web app will be accessible to all users under the expected user load.

Identifying Hidden Bugs

Web load testing is essential for determining hidden errors and bugs in a web application. Errors and bugs in your application can significantly affect the usability and user experience of your product. With the help of web app load testing, we can identify these errors without much trouble and eliminate them before they affect end users.

Facilitating Simultaneous Web App Usage

Since web applications are accessed over the internet, concurrent usage remains a mandatory requirement for these applications. Load testing a web application helps us understand how many concurrent users the software can handle at the same time.

If you expect your business website to host several users at once, it is essential to make sure whether the system can cater to the expected number of users. For websites and web services, load testing is as important as crash testing for vehicles.

Ensuring Customer Retention

You can easily lose both new and old customers if your website or web application breaks down suddenly. Therefore, by preventing website crashes, web application load testing ensures that your business stays afloat and retains all loyal customers.

Performance Improvement

Web development projects can be extremely complex and hard to implement effectively. Therefore, it is not uncommon for these applications to suffer from scalability, stability, and performance issues.

In worst cases, putting mechanisms for detecting bottlenecks can fail as well. This is why we need to rely on website application load testing to help us identify bottlenecks. With the help of load testing, we can optimize databases and written code to reduce the time it takes to process requests while minimizing the likelihood of memory leaks and system crashes.

web app load testing

Load Testing Tools for Web Applications

Load testing tools are necessary for evaluating the effectiveness, reliability, capacity, speed, and scalability of web applications with hardware, network, and user software.There are a number of tools available for load testing web applications. Here is a list of the most used load testing tools for web applications.


JMeter is an open-source software testing tool but is mainly used for load testing web apps.

Core Features:

  • Highly portable
  • Multiple load injectors managed by a single interface
  • Has 100% support for all Java-based apps
  • Simple, yet crisp charts and graphs that display important resource usage monitors and load statistics
  • Has support for integrated real-time, Tomcat collectors
  • Requires minimum scripting efforts as compared to most load testing tools for web apps
  • Simple, intuitive, and easy-to-use


LoadNinja is an easy to use script-less load testing software that offers advanced load testing features.

Core Features:

  • Manages virtual user activity in real-time
  • Doesn’t require server machine and maintenance since it’s hosted on the cloud
  • Offers load test creation without scripts
  • Has real browsers instead of simulation for load test execution at scale
  • Debugs load tests in real-time
  • Specialized browser-based testing metrics with advanced reporting and analytics features


StresStimulus allows testing teams to perform testing operations that are not available in most tools. The tool has the ability to automatically fix playback errors with the help of advanced proprietary autocorrelation features.

Core Features:

  • End-to-end testing features starting from recording scenarios to delivering test results
  • Offers both cloud and on-site testing through multiple load generators
  • Intuitive user interface
  • Available both as a Fiddler add-on or as an individual tool
  • Gives the option to exports scripts in a Visual Studio test format
  • Supports three scripting languages and offers support for manual testing


LoadView is a software testing tool specialized for load testing. It allows testing teams to perform real browser-based load testing for web applications, web APIs, and websites.

Core Features:

  • Offers features for identifying bottlenecks
  • Supports web applications in Java, HTML5, Flash, PHP, Ruby, Silverlight, and others
  • Creates multi-step scripts for load simulation
  • Enables you to build test scripts without coding
  • Cloud-based load testing in real browsers
  • Offers compatibility testing on over 40 mobile and desktop browsers
  • Facilitates capacity planning
web app load testing

Web Application Load Testing

Web application load testing is necessary for determining key vulnerabilities caused by changing user loads. It helps us optimize our websites and web applications in terms of scalability, performance, and stability. At the same time, it reduces the cost of detecting and resolving significant problems in the system and deliver a better user experience.

Source: PFLB