Question

in google chrome, i go to an asp.net web site url after enabling the DOM inspector (F12). If I select the Network tab, I can see the resources requested along with their status, timeline etc. On subsequent requests, I see that the status for some items say ‘304 Not modified’ and some say ‘(from cache)’, including .js,.css and image files.

I was thinking that all css and images are cached, atleast if I request the page immediately. Are these two status messages the same, can someone explain it?

Answer 1

I would guess that the distinction is that a 304 indicates the browser sent a request and the server indicated the resource hadn’t changed, whereas the from cache status may indicate that Chrome didn’t even send a request–the browser knew to use the cache without ever contacting the server.

This could be verified with a tool like Fiddler to see whether from cache resources are ever requested.