Posted By: Morgan Cheng
Is there a standard for what actions F5 and Ctrl + F5 trigger in web browsers?
I once did experiment in IE6 and Firefox 2.x. The F5 refresh would trigger a HTTP request sent to the server with an
If-Modified-Since header, while Ctrl + F5 would not have such a header. In my understanding, F5 will try to utilize cached content as much as possible, while Ctrl + F5 is intended to abandon all cached content and just retrieve all content from the servers again.
But today, I noticed that in some of the latest browsers (Chrome, IE8) it doesn’t work in this way anymore. Both F5 and Ctrl + F5 send the
So how is this supposed to work, or (if there is no standard) how do the major browsers differ in how they implement these refresh features?
F5 may give you the same page even if the content is changed, because it may load the page from cache. But Ctrl–F5 forces a cache refresh, and will guarantee that if the content is changed, you will get the new content.