The purposes of load testing and stress testing are similar, but they are different. The primary distinction between the two is that load tests employ the anticipated load to evaluate the performance of your system during normal or above-average usage, whereas stress tests employ extreme load to determine the threshold at which your system fails due to high traffic and heavy usage.
Stress tests simulate extreme traffic and load tests simulate normal traffic.
It is possible that load tests will crash your test environment, and stress tests will also break your test environment.
Load tests determine if your system is capable of handling the expected traffic volume, and stress tests determine the system’s capacity.
Imagine your web or mobile application as a jumping trampoline you’d like to offer to the public. When you do load testing, you check how well the trampoline works with a certain amount of weight, like four people of average weight. Is it capable of holding them without breaking? Do you think it is still bouncy? Are there any other issues related to the weight and usage?
For a stress test, it is imperative to exceed the anticipated load and continue to load weight onto the trampoline until it breaks. You will examine which part of the trampoline was broken down the most—the springs, the trampoline mat, or the legs. After that, you can either try to make the part of the trampoline that’s weaker or write down any other big problems that happened when it broke, like security problems or data corruption.
The process of load testing and stress testing commences in a similar manner, namely by imposing a load on your application. This means that they both connect with virtual users on your site or app and replicate standard user experiences (for example, home page, search page, product page, shopping cart, checkout)
Both tests help find problems that happen when your website or app is busy and can cause problems.
However, the ultimate objectives differ for a load test in comparison to a stress test.
Comparison:
| Load Testing | Stress Testing |
| Check the software when its used a lot and see if it slows down. | Check the software for performance when its used frequently or in unusual ways. |
| Any issues that are causing the software to run slowly should be fixed. | See how far it can go before it gives up and if itll ever work again. |
| With regular use, the goal is to make sure it works well. | The goal is to figure out what happens when the software is pushed to its limits. |
Should you run a load test or a stress test?
The decision to conduct load testing or stress testing on your site or application hinges on the reason for your interest in performance testing in the first place.
The majority of businesses and organizations merely desire assurance that their service functions as anticipated and remains operational throughout its usage. If this is the case, then a load test is probably more than enough.
But many big companies and groups have higher goals for how well they do things. You might want to do a stress test if you’re worried about security problems and losing data, if you get lots of DDoS attacks and outages, or if you’re setting up advanced monitoring to catch problems before they happen.
Stress tests have the advantage of revealing everything a load test would reveal, including bottlenecks, errors, and performance issues. They also provide additional information related to what happens when your systems crash. But there are some problems with load testing. It costs more money and is more difficult to do, both to run the tests and fix the problems you find.
Stress testing helps you prepare for the worst-case scenario, while load testing helps you prepare for a realistic, expected load. It aids in crafting a system that gracefully experiences system failures and swiftly recovers.
But if your goals are to meet your SLA terms, handle traffic for a big sale or registration, or test a system change, then a load test is probably all you need.
In conclusion, load testing and stress testing ensure that the software youre using works as intended. Load testing ensures that the software is capable of handling regular use, while stress testing examines how it works when things get hectic.
