More and more companies use a REST architecture to implement applications for an easy to use API. One important quality attribute of an application is the performance. To be able to understand how the application will perform it is important to know how the selected framework perform. By testing the performance of different frameworks it will become easier for software developers to choose the right framework to achieve their requirements and goals. At the time when this paper was written the research in this area was limited. This paper answered the question of which framework between Express, .NET Core, Spring and Flask that had the best performance. To be able to know how frameworks performed the author needed to measure them. One way of measuring performance is with response time from the server. The author used a controlled experiment to collect raw data from which the results was drawn. The author found out that Spring had the best overall performance between the different categories. By analysing the results the author also found out that performance differed a lot between the frameworks in some categories.