Speed up Firefox by removing its profile



When Firefox is first installed, it generally appears pretty snappy. However, after a few months of regular use, it appears to get sluggish, even without any add-ons and clearing the cache, cookies, etc.

This slowing down is an ongoing issue I have experienced with Firefox and particularly gets bad after a year, especially with multiple tabs open. Even CCleaner appears to offer little improvement.

When I first ran into this problem several years ago, I decided to try uninstalling Firefox, deleting everything I could find Firefox related on my computer and reinstalled Firefox. The resulting improvement in Firefox was substantial, much like what you would expect from a clean OS installation. Then again, I had a much older rig at the time.

Although this issue is not as bad now with faster PC hardware, it is still surprising just how much better Firefox performs each time I clean the profile. The obvious catch is having to restore my bookmarks, sign-in anywhere I use ‘Remember Me’ and restore the odd add-ons I use (e.g. UK dictionary).

Here are the steps to remove Firefox’s profile:

[li]Backup your bookmarks - Launch Firefox, Press Shift+Ctrl+B, go into “Import and Backup” and select “Backup”. Save your bookmarks somewhere handy such as on your desktop.
[/li][li]Go into the Firefox Apps list and take note of any Apps you use or any settings configured on any app, as these will need to be reapplied when the apps are later reinstalled.
[/li][li]Completely close out of Firefox.
[/li][li]Go into Run (Windows Key + R), type in “%appdata%” and click ‘OK’.
[/li][li]Go into the ‘Mozilla’ folder and rename ‘Firefox’ to ‘Firefox.old’.
[/li][li]Go up two levels (AppData folder), then go into ‘Roaming’ and then into ‘Mozilla’. Rename ‘Firefox’ to ‘Firefox.old’.
[/li][li]Launch Firefox - It will now act like it is freshly installed. I’d recommend choosing the ‘Don’t import anything’ option when requested.
[/li][li]Go into bookmarks (Shift+Ctrl+B), go into “Import and Backup”, then “Restore” and “Choose File”. Choose the bookmarks file you saved in step 1.
[/li][li]Reinstall and configure any apps you would like to continue using in Firefox.

At this stage, Firefox should be pretty snappy again, at least for another few months. :wink:


That’s a very useful guide Seán, thanks for that. :flower:



I use an add on called FEBE for backing up various components of Firefox. It would work well with this procedure and make reinstalling bookmarks, passwords, preferences, add ons etc. very easy.


I inadvertently wiped the Firefox profile on my main desktop a few months ago when I uninstalled the 64-bit of Firefox (Aurora) that I was no longer using.

From what I recall, it asked if I would like to keep the user data during uninstallation, in which case I would have selected ‘no’, not realising it would take out the Firefox profile along with it. When I launched Firefox, I got a surprise when it acted like it was freshly installed. In that case, I had to restore my bookmarks from the last PC backup, but at least meant not manually having to do the above process for a while.


I use a different approach to keep Firefox snappy…I moved my profile to a ramdisk,installed my favorite extensions and themes and have setup the ramdisk to flush on every reboot.
If there are any updates,I untick that option,install the updates and then reboot my pc and let Firefox run 1 or 2 times before enabling the flushing again…:slight_smile:


Odd my FF is fast or same as when first installed? I just use CCleaner and clean and back in business. I now have FF33 on a clean install or rather new build since the last build now has gone to the great beyond. Only slugssish came from to many windows or tabs opened or multitasking to much with little RAM. I think I might also be a problem with not having enough RAM as well. When I had 4G I sometimes experiences sluggish speeds with my task but with 8G that now is gone mostly unless I have a CPU intensive app running then I will have slugish response in all other operations and I have like 7 addons in my FF as well. Will upgrade to 16G when budget allows just to give me more head room to work with.


I just created a new profile, kept the old one too.


At work today, I didn’t realise just how bloated my Firefox profile got until I tried playing a YouTube clip and it kept flickering and stuttering, whereas Chrome would play it fine.

Upon checking Task Manager, it was clear something was hogging the CPU. Sure enough it was Firefox as the CPU usage went to near zero when I closed it. However, as soon as I opened Firefox, it started hogging about 50% CPU usage non-stop just left idle on its homepage:

I did notice my PC running slower than usual recently and indeed this was the culprit as usually I minimise Firefox, not realising it was lately taking up half my CPU usage.

So I figured it was time to clear its profile and indeed the local Firefox profile was pretty large:

It’s also worth noting that this is after running CCleaner, so while it does a pretty good job at clearing Internet Explorer’s cache, it seems to leave a lot behind with Firefox.

So for curiosity, I just renamed this one folder (steps 4 & 5 in post #1) and opened up Firefox. What a difference…

Unfortunately, this didn’t solve the issue I’m having with YouTube as the video still keeps flickering back and forth between frames, even though YouTube plays fine on Internet Explorer and Chrome.

On the other hand, renaming (or deleting) that one Firefox folder doesn’t wipe cookies, URL history, bookmarks, etc. so can be a handy way of speeding up Firefox without a total profile clear out.


Wow, that’s an amazing difference Séan! :eek:



[QUOTE=Seán;2768453]Unfortunately, this didn’t solve the issue I’m having with YouTube as the video still keeps flickering back and forth between frames, even though YouTube plays fine on Internet Explorer and Chrome.[/QUOTE]

I had to stop using the latest FireFox 44.0.2 as it will freeze my PC entirely at the moment I try to click a link to a youtube video. This has not happened before, and does not happen in Pale Moon or any other based on the engine…
No BSOD, no nothing to report to Mozilla either, just a total freeze with 5sec power-button as the solution… I will retry when the next update comes along, but for now using FF is out of the question.

Just thought I should mention it since I saw your message. :flower: