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There are times when the firefox responds reluctantly. And it is not only when i have opened many tabs. But there are cases when i have opened as many as 20 tabs and firefox is working fine and there are chances when i have opened just 5-6 tabs and firefox behaves lazy.
So, i guess it do not depend on number of tabs and there must be any specific tab which causes the problem.
Isn't there a way to find that tab out and close only that instead of closing complete firefox? Is there any addon for that, or any script?

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4 Answers 4

up vote 6 down vote accepted

The BarTab extension for Firefox might be useful for improving the situation :

BarTab can intercept when tabs are loaded in the background or restored after a browser restart and will only load the content when the tab is actually visited. It also allows you to free memory by unloading already loaded tabs, either manually or automatically.

Otherwise, you might switch temporarily to Google Chrome, where shift-esc displays the per-tab usage:


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BarTab seems promising. I don't use Chrome as it is not having those addons which i like. –  Rakesh Juyal Apr 1 '11 at 6:47
Please note: Not currently available for Firefox 11.0 –  Nathan Koop Apr 13 '12 at 18:31
@NathanKoop: FF compatibility has become rather meaningless with the current version speedup. I use the Add-on Compatibility Reporter to untangle the mess. –  harrymc Apr 13 '12 at 18:42
2… - works for 17.01 –  Enigma Mar 1 '13 at 18:18
Not available in Firefox 40. –  Ricardo Martins Aug 19 at 0:01

For Firefox, I've made an addon which displays tab memory usage in the corresponding tab's title.

Provides user with tab related stats and memory usage ..



  • How many tabs are currently open
  • How many tabs have been opened during this Firefox session
  • How many tabs have been opened since addon installed
  • Display tab memory usage in title
  • Preference to toggle tab memory usage on/off
  • Preference to set interval between memory usage collection
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Do you know ANY way to find out even a hint as to which TAB (or even relevant URL) is eating CPU? –  tbone Mar 15 at 17:54
Afraid I don't at the moment, but once I find out I plan on including that data in the addon too. –  bobbyrne01 Mar 18 at 17:56
I'll ask since you may have the knowledge....these various addons that "unload" tabs - in my experience, they seem to visually unload them, but Firefox doesn't give up any of that memory; or, when you restart Firefox, it seems to eat all of the memory required for the opened tabs, even before you click on each one and it loads (implying they are being physically loaded in the background, but not displayed). Would you happen to know if this IS in fact the situation? –  tbone Mar 18 at 20:28
@bobbyrne01 I am using your addon right now! Good stuff. –  AntonioCS Sep 27 at 21:47

You can go to about:memory and click on Measure to see the memory usage for each tab.

It doesn't look as pretty as Chrome's memory view but it does the job.

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It would be perfect if we have one for cpu. :) –  Ricardo Martins Aug 19 at 0:11

Opening the browser to about:memory can show per-tab memory usage.

For more information:

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