Have you ever wondered, how not to cache your SWF file in user machine? If it’s not cached, it help us in following ways • Every time a client open a page, will get new SWF • User can not copy your SWF from temp folder and decompile it • It adds additional security to your hard work. Here is the way around:- Don’t give the direct http path of SWF file when you embed, use a server side proxy code to request content of the FILE That server side will deliver and secure your file on server. It’s like abstracting other request from direct access to your SWF files. And change the response header to not to cache A sample code in PHP can be like $filename = "test_cache.swf"; header('Content-type: application/x-shockwave-flash'); header("Expires: Thu, 01 Jan 1970 00:00:00 GMT, -1 "); header("Cache-Control: no-cache, no-store, must-revalidate"); header("Pragma: no-cache"); $content = file_get_contents($filename); echo$content;