How to find out if the code comes from the local cache and server

Question

Is there a way in fiddler to find out if some piece of code (jscript, jquery, css) is loaded from the local cache and downloaded from the server. I think this may be represented in different colors in web sessions, but could not find a legend for these colors.

Answer 1

If you see 304 Not Modified responses, this means that the client made a conditional request, and the server signals “no need to download, you have the latest version, cached”. This "class" of cached responses.

However, even conditional requests are not sent for some objects ( Expires header in the future, etc. - see RFC2616 ). They will not appear at all in Fiddler, since there is no request at all - the client may assume that the cached version is fresh.

What you certainly can see is not cached resources - everything returned with a response code from the 2xx range should not be cached (unless there is a seriously incorrectly configured caching proxy up, but this is rare these days) .

You can clear your caches and open the page. Save these results. Then open the page again - see what is missing compared to the first download; they are cached.

Answer 2

Fiddler is an HTTP proxy, so it doesn't show cached content at all.