In order to learn how to test your APIs, especially how to load test your APIs, let’s first find out some essential info on APIs and RESTful APIs.

Standard Deviation is an important metric in performance testing analysis and informs us how stable the application under test is. In other words, it tells us if the requests that occur during the test are consistent or not. Standard Deviation measures how the response times are spread out around the average response time (mean). A small standard deviation means that the response time of all the requests are close to each other.