jQuery.ajax: getAllResponseHeaders hack is no longer needed This was fixed in FF21 a while ago as well as in webkit and blink: https://bugs.webkit.org/show_bug.cgi?id=41210 https://code.google.com/p/chromium/issues/detail?id=87338 https://bugs.webkit.org/show_bug.cgi?id=76419 https://bugzilla.mozilla.org/show_bug.cgi?id=608735 confirmed using http://jsfiddle.net/xeBub/7/ in browserstack