How to Determine which Firefox Add-ons are Using the Most Memory

I love Firefox for its add-ons. I have a lot of them installed, which obviously increases memory use. But it seems that some add-ons are better than others in that department. Does anyone know a way to figure out approximately how much memory each add-on is using? Obviously, I could disable them all and try them one at a time, but I'm hoping for an easier way...


I usually deal with Firefox memory issues by installing two different Firefox'es on my computer. The first one is the default Firefox and the other is portable Firefox.

I install all the addons I am ever going to use on the portable Firefox (FF) I install the addons which are used almost daily on the default Firefox.

This way I can use the addon just by switching over to the portable Firefox.

If this is not the solution you are looking for then try these addons

  1. AFOM - AFOM recovers Memory Leakage within the Firefox application. (Windows only)
    NOTE: This add-on has been removed by its author.

  2. CacheViewer - Allows searching and sorting memory and disk cache files.
    CacheViewer is discontinued please use CacheViewer Continued.
    EDIT: I tried it, and it shows all the files used by Firefox in the cache which eat up precious memory.

  3. bosskey - Add Boss Key, Minimize/Close to tray and memory auto cleaning to Firefox.

  4. RAMBack - RAMBack will cause Firefox to issue an internal notification to free up memory that is otherwise held for performance purposes.


There's an extension called Leak Monitor that monitors add-ons for a certain type of memory leak...not exactly what you're looking for, but it's a start!


Only slightly less tedious:

  • Check memory usage of Firefox + all plugins.
  • Disable them all & check memory usage - difference is due to plugins.
  • Enable half a dozen (say), check memory usage.
  • If the increase is not too great repeat with the next batch.
  • If the increase is a large proportion of the usage then disable that batch and check each one individually.
  • Repeat until all plugins added.

Obviously this is probably a non starter if you have lots of plugins.

Searching for more information on those plugins might tell you something as well.