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My Firefox(24.0) is currently suffering quite badly in terms of performance, no smooth flow scrolling(smooth scroll enabled), even the page loading favicon is not smooth, CPU usage is high and video stream is choppy. And I am pretty convinced that it has to with Firefox not Ubuntu 13.04 which I am currently using.

What I have tried, without being of any help:

  • This
  • setting browser.sessionstore.interval to 300000
  • Disabling hardware acceleration
  • Issue persisted while running Firefox in safe-mode (therefore it isn't the add-ons)

What makes me sure it has to with Firefox and not the OS?

I was just exploring Conkeror and went to a video link through it. Everything was crisp and smooth and no choppy video, although I played the video in 720p while I did it at 360p in Firefox.

Background which might be relevant:

I don't clear my browsing/downloading history and have set Firefox, virtually, never to do so. And there is currently several years of it.

Any analyses technique to figure out what/who actually is the culprit in this case? Profiling? Any suggestion(s)?


Logging into Guest session and browsing, meaning a mint Firefox profile, didn't produce the above mentioned result.

share|improve this question
First off, create a new account with the profile manager and see if the erratic behavior is isolated to your account (profile). Update your question with those findings. – Ярослав Рахматуллин Sep 28 '13 at 20:09
@hus787 Sounds like an add-on could be causing the issue. Try disabling your add-ons, one by one, to see if the issue clears up. – iglvzx Sep 28 '13 at 20:45
I have experienced Firefox to exhibit issues related to old and "heavy" profiles. I find that the best strategy to avoid these problems is to automate the re-installation of plugins and to regularly backup important bookmarks and such. Mozilla actually offers a service to sync your data, so if willing to risk that information leaking to the-whatever, you could store your browser history and such with them (or even run a sync-server locally). The moral is, sometimes profiles get corrupted, and no one is willing to troubleshoot (not even their support service). So unless you are a ff dev.. – Ярослав Рахматуллин Sep 28 '13 at 21:02
@iglvzx like I mentioned, I ran ff in safe mode, meaning all add-ons disabled – Bleeding Fingers Sep 29 '13 at 19:34
@ЯрославРахматуллин actually that ff sync server looks pretty secure and I would have entrusted me data with them, but the problem is they don't provided space of more then 25MB(don't remember the source) and my raw data is above 100MB. That's why I backup locally. And I'll discuss it below in the answer it a really small thing that had gone haywire – Bleeding Fingers Sep 29 '13 at 19:44

Reset instructions for the impatient

  1. Export stored passwords (optional)
  2. Save a list of installed extensions
  3. Save a list valued preferences
  4. Reset (i.e delete preferences, extension, dictionaries, themes)

    Firefox > Help > Troubleshooting Information
         => [Reset Firefox...] > [Reset Firefox]

And the patient

Follow these steps to reset you firefox. Don't worry, bookmarks etc will be save.

  1. On the menu bar, click the Help menu and select Troubleshooting Information.
  2. Click the Reset Firefox… button in the upper-right corner of the Troubleshooting Information page.
  3. To continue, click Reset Firefox in the confirmation sheet that slides down.
  4. Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Done and Firefox will open.


share|improve this answer
Link-only answers are a no-no. Please include pertinent information directly in your answer, to avoid possible future link-rot. – Ƭᴇcʜιᴇ007 Sep 28 '13 at 20:33
Alright thx. I will edit it. – Christian Woerz Sep 28 '13 at 20:33
Never knew about this, very nice! – brianbaligad Sep 29 '13 at 7:22
Backup addon for Firefox: Check out the other addons by that author as well. – Ярослав Рахматуллин Jan 23 '14 at 23:50

Chris's answer surely helped me march in the right direction, but there were a few things that solution did that I didn't want.

It got me rid of the download history, current session and preferences ( and other *can-do-without*s). The download history and session I wasn't willing to give-up, could do without the preferences but choose to restore it too. So after a few attempts I narrowed it down to prefs.js. Bringing back the entire untouched profile, which I had when I posted the question and was having the problem, and just getting rid of the prefs.js file in it solved my problem.

Then I manually restored some of my preferences. I could send the my culprit prefs.js file to the ff dev team if it could be of any help. Since I haven't yet found out which particular set of preference(s) had spoiled my ff.

share|improve this answer

Since your problem does not occur on blank profile, it may be addon-related. Could you please:

  1. open Firefox with the problematic profile,
  2. open Addon Manager,
  3. disable all your addons.

If the problem is gone, re-enable extensions one by one to find the faulty one.

(do not use the Safe Mode, do it manually in standard mode)

share|improve this answer
I have clearly mentioned in the question what I have tried, i.e. to say, "Running Firefox in safe-mode" which means disabling all the add-ons. – Bleeding Fingers Sep 29 '13 at 20:56
Running Firefox in Safe Mode does not solve anything... unless the problem was also present in Safe Mode? Please straighten that up. – Michał Sacharewicz Sep 29 '13 at 20:58
could you defend you're last statement? Because ff does give the convenient option of doing so by going to help->restart with addons disabled, which leads to a restart in safe-mode, – Bleeding Fingers Sep 29 '13 at 20:59
As long as you are in Safe Mode sessions, addons are disabled, but that does not fix anything for longer than that session. Once you launch FF in normal mode again, addons are back up. – Michał Sacharewicz Sep 29 '13 at 21:01
question updated/made more precise. In short safe-mode was of no help. – Bleeding Fingers Sep 29 '13 at 21:04

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