Why are background images not cached?

depends on browser or what?

[flashfan]

I checked the access log, browser (IE or FF) makes new requests for all background images (in external css). Why are they not cached?

[Span]

As far as I know, normally, background images should be cached. But I think you have to look at the server response code in your logs too. In case of a 304 there is a request, but nothing is send to the browser.

Not Modified 304
If the client has done a conditional GET and access is allowed, but the document has not been modified since the date and time specified in If-Modified-Since field, the server responds with a 304 status code and does not send the document body to the client.

You can check the cacheability of your page and images with a cachebility checker like this one: [ircache.net...]

[flashfan]

Yes, you are right. The server returns 304 code. Thanks! Now I am clear.