Load Testing vs Stress Testing vs Performance Testing: Difference Discussed

What is Performance testing?

Performance testing is a type of testing for determining the speed of a computer, network or device. It checks the performance of the components of a system by passing different parameters in different load scenarios.

What is Load testing?

Load testing is the process that simulates actual user load on any application or website. It checks how the application behaves during normal and high loads. This type of testing is applied when a development project nears to its completion.

What is Stress testing?

Stress testing is a type of testing that determines the stability and robustness of the system. It is a non-functional testing technique. This testing technique uses auto-generated simulation model that checks all the hypothetical scenarios.

Performance Testing vs. Load Testing vs. Stress Testing

Performance testing Load testing Stress testing
Superset of load and stress testing. A subset of performance testing. A subset of performance testing.
Helps to set the benchmark and standards for the application. To recognize the upper limit of the system, set SLA of the app and check how the system can handle a heavy load. To check out how the system behaves under extreme loads and how it recovers from failure.
The aim of performance testing is to get an indication of how an application behaves under regular parameters. Generating increased load on a web application is the main aim of load testing. Stress testing aims to ensure that under a sudden high load for a considerable duration the servers don’t crash.
Resource usage, availability, and reliability of the product are validated under this testing. The attributes which are checked in a load test are peak performance, server quantity and response time. This kind of testing checks stability response time, etc.
In performance testing, Load limit is both below and above the threshold of a break. In load testing load limit is a threshold of a break. In stress testing load limit is above the threshold of a break.
Example of performance testing are : Checking concurrent users, HTTP connections or checking
Suitable response time.
Example of Load testing are Test of a word processor by make change in the large volume of data,

test a printer by transferring heavy data.

Check mail server with thousands of concurrent users.

Example of Stress testing is casually shut down and restart ports of a large network.
Why Performance Testing?

-Validating that application performs properly

-Validating to conform the performance needs of the business

Finding, analyzing and, fixing performance issues

Validating the hardware adequate to handle the expected load.

Doing capacity planning for future demand of the application

Why Load Testing?

-Find bugs which are not possible with any other testing method. Such as memory management memory leaks, bugs, buffer overflows, etc.

-To assure that application able to achieve the performance point recognized during performance testing.

-To determine the operating capacity of an application

-To check out that current infrastructure is sufficient to run the application or not.

-Numbers of concurrent users which an application can support, and scalability to allow more users to access it.

Why Stress Testing?

-It helps the testing unit to test the system in the situation of failures.

-To make sure that the system has saved the data before crashing or not.

-To check whether any unexpected failures do not harm the system security.

When do you use Performance Testing?

Performance testing is done to check the performance of website servers, database, and network. If you are adopting waterfall methodology, then it is important for you to check each time release of a new version. However, if you are using the agile software development approach, then you need to test application continuously.

When do you use Load testing?

Load testing is performed to determine how many users the system can handle. You can also check out different scenarios that let you focus on different parts of your system. Like the home page or checkout webpage on your website for web load testing. It also helps you to determine how the load builds and sustains in the system.

When do you Use Stress Testing?

Website and app stress tests are significant before big events such as ticket selling for a famous concert with high demand of the people. So it is very important to test regularly to the capacity of the system endurance. This also helps you to prepare for unexpected traffic spikes and gives more time and resources to fix any bottlenecks.


  • Performance testing is a testing method used to determine the speed of a computer, network or devices.
  • Load testing simulates real-world load on any application or website.
  • Stress testing determines the stability and robustness of the system
  • Performance testing helps to check the performance of website servers, databases, networks.
  • Load testing is used for the Client/Server, Web-based applications.
  • Stress testing is done unexpected test traffic of your website.