I read that when you don't have access to the web server's headers you can turn off the cache using:
<meta http-equiv="Cache-Control" content="no-store" />
But I also read that this doesn't work in some versions of IE. Are there any set of <meta> tags that will turn off cache in all browsers?
For modern web browsers (After IE9)
See the Duplicate listed at the top of the page for correct information!
See answer here: How to control web page caching, across all browsers?
For IE9 and before
Do not blindly copy paste this!
The list is just examples of different techniques, it's not for direct insertion. If copied, the second would overwrite the first and the fourth would overwrite the third because of the http-equiv declarations AND fail with the W3C validator. At most, one could have one of each http-equiv declarations; pragma, cache-control and expires. These are completely outdated when using modern up to date browsers. After IE9 anyway. Chrome and Firefox specifically does not work with these as you would expect, if at all.
<meta http-equiv="cache-control" content="max-age=0" /> <meta http-equiv="cache-control" content="no-cache" /> <meta http-equiv="expires" content="0" /> <meta http-equiv="expires" content="Tue, 01 Jan 1980 1:00:00 GMT" /> <meta http-equiv="pragma" content="no-cache" />
Actually do not use these at all!
Caching headers are unreliable in meta elements; for one, any web proxies between the site and the user will completely ignore them. You should always use a real HTTP header for headers such as Cache-Control and Pragma.
According to Independent Security Evaluators' great case study on the industry-wide misunderstanding of controlling caches, only
Cache-Control: no-store is recognized by Chrome, Firefox, and IE. IE recognizes other controls, but Chrome and Firefox do not.
It doesn't work in IE5, but that's not a big issue.
However, cacheing headers are unreliable in meta elements; for one, any web proxies between the site and the user will completely ignore them. You should always use a real HTTP header for headers such as Cache-Control and Pragma.
pragma is your best bet:
<meta http-equiv="Pragma" content="no-cache">
I noticed some caching issues with service calls when repeating the same service call (long polling). Adding metadata didn't help. One solution is to pass a
timestamp to ensure
ie thinks it's a different
http service request. That worked for me, so adding a server side scripting code snippet to automatically update this tag wouldn't hurt:
<meta http-equiv="expires" content="timestamp">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache"> <META HTTP-EQUIV="Expires" CONTENT="-1">