Have you tried running without any extensions after having reset Firefox? The only time I&#x27;ve seen that where it wasn&#x27;t a dying hard drive or a malware-infested&#x2F;corporate IT-mismanaged system was when someone had some particularly poorly-optimized extensions installed.<p>I was curious &amp; ran a couple of tests on this 2010 Mac Book Air. Normal launch time according to about:healthreport is 2.8 seconds and testing with something like `open -a Firefox <a href="https:&#x2F;&#x2F;www.google.com`" rel="nofollow">https:&#x2F;&#x2F;www.google.com`</a> when Firefox was not already running takes 4-5 seconds to finish rendering. When it is already running, it&#x27;s under a second from start to finish.