Load Testing

What is Load Testing?

Load testing is one of the types of performance testing using which we evaluate the performance of an application under expected real-world load.


Virtual users are created to simulate a load of multiple concurrent users accessing the application. After subjecting the application to the virtual user load, we eventually measure the different performance attributes along with identifying performance bottlenecks.


The virtual user creation is performed by tools like – JMeter and LoadRunner.

These performance testing tools allow us to create scripts that make different requests to the server, just like real-world users. Along with that these tools provide, various configurations like-

  • Number of threads or virtual users
  • Duration of load test
  • Performance attributes
  • Graphs that we want to analyze, etc.

After the script creation and setting up of the test configuration, we can run the load test and analyze the test results.

Advantages of Load Testing

  • It helps in the identification of performance bottlenecks before production deployment.

  • It helps in configuring the most optimal infrastructure for the setup. Infrastructure costs can be saved by terminating extra machines. Also, the additional machine can be added in the case of suboptimal infrastructure.

  • It minimizes the risk of downtime by identifying and isolating the requests whose performance needs to be improved.

  • It provides a sense of confidence and reliability in the application’s performance.

Disadvantages of Load Testing

  • Many of the load testing tools are licensed and charge a good amount of money for the license.

  • Even in the case of free and open-source tools like JMeter, an environment is required which should be as close to the production environment setup as possible. This again leads to additional resources and costs.

  • Load test script creation requires scripting knowledge of the language supported by the tool.

  • Incorrectly configured or scripted load test plan/script can lead to false performance issues which take a considerable amount of time and resources.

Performance testing and Load Testing – Are the same?

Load testing is actually a type of performance testing that focuses on analyzing the behavior of web applications under a particular load, for a predefined amount of time.

Whereas, performance testing is a broader term that includes checking different aspects of the system like-

  • Application’s state at workload higher than expected – stress testing;
  • Performance of application with a large volume of data – volume testing;
  • The ability of the system to sustain normal workload for a large duration of time – endurance testing, etc.

You can learn about different performance testing concepts and script creation from our Apache JMeter tutorial.


That’s it from my side, if you require any further information, let me know in the comment. Also, check out our software testing tutorial here.

Software Testing Tutorial – Complete Guide


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