There is a number of Web APIs which allow you to measure the performance of web applications:
User Timing API (access to high precision timestamps).
Resource Timing API (timing information related to resources on a document).
Navigation Timing API (timing information related to navigation and elements).
The youngest member of the family is Server Timing API which allows for communicating the server performance metrics to the client. The API is not widely supported yet, but Chrome Devtools is able to interpret the information sent from the server and expose it as part of the request timing information. Let’s see how this feature can be utilized from ASP.NET Core.