Additionally, I will point out that the "cache: false" that people are discussing does not seem to be documented as part of the XHR interface; it is only something jQuery manipulates, and it seems to do nothing very useful with it: all it means is "if this is a GET/HEAD request, append a query-string with a millisecond-accurate timestamp"; it does nothing for POST requests, and it does not add any cache control headers to the request that could be used to indicate to either the browser or to upstream proxies that the content should not be returned from a cache.