Understanding the timing values from Charles debugging proxy

charles-proxy, http, performance

Solution

From the documentation:

- Request - the time spent sending (uploading) the request (dark blue)

- Latency - the time spent waiting for network latency or processing time on the server (mid blue)

- Response - the time spent receiving (downloading) the response (light blue)

Problem

This image from Charles shows some pretty interesting information: - Duration - Request Duration - Response Duration - Latency I'd like to better understand what these terms actually mean. ie., How does Charles measure the request duration? (In the course of a HTTP transaction, this is the time from when-to-when?) Likewise for response. Also, `request + response != Duration`. Is the remainder server-side processing time? What is Latency a measure of here?

Original source