Locust is a open source load testing tool for Python. https://locust.io/ It is a easy and fast way to performance test a site both local and production. When running a test you get a Response Times (ms) diagram. You get a Median Reponse Time and a 95% percentile. What is this Locust 95% percentile then? First of, the percentiles are approximated in Locust due to performance. It is calculated and it means 95% of the request took less time than this. It is showing the max of 95% of the counts.