One would need more info than "my firefox is slow" to see why. You can try refreshing firefox / starting in safe mode to see if that helps. Without more info, though, idk :/

Hi, Fair enough, its just seems awful on all platforms. So PC I`m typing on, Windows 7 Pro with Kaspersky Antivirus.

Following Extensions: Adblock Plus, Disconnect, Kaspersky, One Tab, Auto Tab Discard.

I have tried the following: Disable multi-process windows, Decrease content process limit, Toggle Hardware Acceleration, Run in safe mode/Disable extensions, Delete Firefox preference files.

Just typing now Firefox is using 3.5GB memory and 50% CPU, the lag while typing is horrific.

I have not tried the refresh, what will I lose if I refresh firefox? Thanks in advance.....

Refreshing Firefox {web link} is a LAST RESORT ! !

Refreshing Firefox -- easily fix most problems

If you're having problems with Firefox, refreshing it can help. The refresh feature fixes many issues by restoring Firefox to its factory default state while saving your essential information like bookmarks and open tabs. Everything else, like user settings and add-ons, are removed. Note: Refresh saves your old profile to the desktop in a folder called Old Firefox.

You can see what refresh does here: https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings There may be many reasons why firefox is using those resources. If you want to see if firefox is fetching everything correctrly, you can look at your about:support page. As for perofrmance settings, you might just try using the recommended settings in about:preferences. I don't know about the extension, but imo ublock origin is good for effecienct ad blocking.

Use these links to create a new profile. Use this new profile as is. Is the problem still there?

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Type about:profiles<enter> in the address bar.

Hi, I setup the new profile, opened 4 common pages ,checked the memory use, then opened it up with my original profile, same 5 pages (+1 which is the Onetab extension page that always opens) and the memory usage was more or less the same (0.85GBish). Neither profile had the massive lag it sometimes has.

 I shall check about:support page when I get time.

Thanks so far, I imagine this wont be the last of it!

What should I be looking for in the about:support page?