This can happen by many of our improper usage of Firefox. In here I mentioned few causes which you should consider about your Firefox browser.
Firefox extensions and themes:
Most common cause is Firefox extensions and themes, if you have installed lots of extensions and themes probably your browser very slow and show high memory usage.
Overall performance of your computer can be reducing.Check your Add-ons, Themes and remove all unnecessary extensions and themes.
Compare your extensions with
Problematic extensions published by mozillazine and follow the recommendations there if any extension found.
Update all your extensions to newest versions, newest versions have lots of improvements and bug fixes for smooth usage.
Still your browser remaining the same status it’s proper to go through this tutorial and follow every this which I discussed here.
Check your extensions for high memory usage:
Let’s check the remaining extensions for memory usage. Even any of your extension not in the
Problematic extensions it isn't guarantees that all your extensions are perfect.Open task manager and in “processes” tab check the memory usage of Firefox and write it down somewhere.
Exit from Firefox, Go to start and run type "Firefox -safe-mode" without double quotation marksCheck Disable all add-ons in opened window and click “continue with safe mood”Again in task manager check memory usage of Firefox and compare with previous result.
If there is high flow of memory usage there is an extension still want be removing.Again open Firefox in normal mood, go to "tools" "add-ons" and disable extensions one by one and compare the memory usage after disabling each and restarting the browser.
If you find huge memory reduction after disabling any particular extension that one should be removed if it's not providing a precious service.
Firefox Plug-ins:
Firefox plug-ins also acts as a devil in sometime, so it is better to read
plug-ins section of mozillazine which has all the information and trouble shootings for latest plug-ins.
It is recommended you to pay your attention about Quicktime, Java, RealPlayer, Windows Media Player, Flash as they use normally.
Clear your Cookies and Download History:Remaining cookies, history and download history is also impact to speed of Firefox.
Removing them every day after done all of work is can be cause for better performance.Go to "tools" "Options" "privacy" and check "Always clear my private data when I close firefox" under private data and in "settings" (right to check box) select all available options and click ok.
This will prompt you to delete your junk data every time you close your firefox browser.
about:config Settings:
Type "about:config" bar and check "browser.cache.memory.enable" is true or not if it is false double click on it and change the attribute to true.
Right click on anywhere of the window and go to New > "Boolean" and enter "config.trim_on_minimize" set attribute to true. This will automatically reduce the memory usage when your browser is minimized.
