Mozilla Firefox Is Running Really Slow

I usually had two different symptoms where my Firefox was just running really slow.

  1. I only had like 2 or 3 add-ons installed and it was slow not just to browse websites but to open a new tab or just to open up the “Preferences” dialog window.
  2. The other symptom I had was that any site that used JavaScript would make Firefox completely freak it out and go Not Responding for sometimes a minute or more before snapping back to life.


To try to fix the crash follow these steps:

  1. Unistall Firefox (remove everything)
  2. Delete your profile:
    I think its like C:\\Users\Shared\Roaming\Mozilla\Firefox. Make sure to save your passwords and bookmarks before doing this, you can export your passwords with an add-on and you can export your bookmarks right from the bookmark window.
  3. Use a tool like CCleaner to make sure all the Firefox registry entries are deleted.
  4. Make sure Firefox is gone from your Program Files folder. We want no traces of it except the backup copy of your passwords and bookmarks.
  5. Then, reinstall Firefox, and reimport all of your old passwords and bookmarks.
  6. I bet this will solve your issue. If not, then that can only be caused by a virus on your computer, or something like you don’t have enough RAM.

    In the latter, open up your task maanger (CTRL + ALT + DEL) and see what is hogging all your processor and RAM and shut it down, or install some more memory.

    Otherwise you can try to restore Firefox default settings without unistall it.

    If you have any question, please drop us a comment!

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