Far future expire header and HTTP 304

Question

I'm trying to optimize the loading time of a website. One of the things I've done is set a far-futures expires header for static content so that they are cached (as described by Yahoo). However, even though they are cached, the browser still sends a request and gets back a 304 (Not Modified) response for that resource.

I realize the 304 response is very small and probably has minimal performance effect, but is there a way to make it such that the browser will no longer send the request at all and just always use the cache for that resource?

Answer 1

You may want to try turning off ETags if you are sending both etags and expires. Some people suggest turning off eTags, especially if you have a load balancer.

Also, note, when you press reload on your page, Firefox WILL recheck all the resources. These will come back with 304's. If you press shift-reload, it will re-request all the resources without etags. So don't use the refresh/reload button to test your last-modifed/etag settings.