Firefox is a great web browser, but it eats your memory very fast. Even if I just keep Firefox idle with one or two sites open, its memory usage quadruples in only a few hours. This is why some people use tricks of restarting Firefox every 30 minutes or so, in order to reduce its memory consumption. But restarting Firefox periodically is not very practical. Instead, you can use the Memory Fox extension that strives to reduce the memory utilized by Firefox and Adobe Flash Player plugins.
You can install the Memory Fox extension from the Mozilla add-ons website. The installation of this add-on requires you to restart the web browser and it can be used immediately after the restart. After the restart, you will see a new icon with letter M to the right side of the location bar in Firefox. You can click on this icon and select to activate the Memory Fox add-on for browser or all processes.
The toolbar M icon would turn to green color for activating Memory Fox only for the browser or to yellow color for activating Memory Fox for all the processes. Activating Memory Fox for browser will try to recover unused memory that is being held by Firefox. If you activate Memory Fox for all processes, then it would also try to recover memory held back by plugins like Adobe Flash Player or Silverlight.
In the settings for Memory Fox, you can set the time period after which memory is recovered from background tabs, idle Firefox browser windows and other related processes. You can also choose to enable event logging for Memory Fox so that you can view the events in Windows Event Viewer.
I used Windows Task Manager (you can run it by pressing the hotkey Ctrl + Shift + Esc) to view the memory usage of Firefox. The memory usage before using Memory Fox was around 112MB. After activating Memory Fox the memory usage came down to only 3 MB! Memory Fox reduced the memory usage by more than 97%. This is a very impressive. At the same time, Firefox was working fine without any glitches.
So if you are having troubles with heavy memory consumption by Firefox, unresponsive Youtube videos or crashing Firefox windows, then its time to install the Memory Fox extension for Firefox. It does not let Firefox hog all your system memory and makes it available to other processes on your system.
You can download and install the Memory Fox add-on from https://addons.mozilla.org/.