Slow doing what? Do you have the same issue with Firefox in Safe Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf Did you clear the browser cache? https://support.mozilla.org/en-US/kb/how-clear-firefox-cache https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox You can also Refresh Firefox, but make you back up your bookmarks and any other data you don't want to lose. https://support.mozilla.org/en-US/kb/reset-preferences-fix-problems