This PHP function will delete all valid cookies for a domain. We’re also sanitizing the cookie variable names from invalid characters.
function clearAllCookies(){ $cookies = explode(';', $_SERVER['HTTP_COOKIE']); foreach($cookies as $cookie) { $parts = explode('=', $cookie); $name = trim($parts[0]); /* this removes any invalid cookie names preventing this warning: PHP Warning: Cookie names cannot contain any of the following '=,; \\t\\r\\n\\013\\014' */ $name = str_replace(array("=", ",", ";", " ", "\t","\r","\n",chr(013),chr(014)), "", $name); if($name <> ''){ setcookie($name, '', time()-1000); setcookie($name, '', time()-1000, '/'); } } }