How to Minimize Firefox Memory Usage

1. Method 1 - -
   
   (1)Open Firefox and click Tools in the browser top menu, then click Options > Privacy.
   
   (2)In the 'History' section, leave 'Remember what I’ve downloaded' unchecked.
   
   (3)In the 'Private Data' section, click the button 'Clear now...', when the dialog box comes up, put a check mark beside these items: Cache, Saved From and Searched History, Offline Website Data. You can mark the 'Cookies', too, if you want. Click 'OK'.

2. Step 2

   - - Method 2 - -
   
   (1)In the Firefox address bar type [about:config], minus the brackets, and press Enter. Click the button "I’ll be careful, I promise!" if you are seeing a warning message.
   
   Next, create a Boolean (false) value and name it "config.trim_on_minimize", without quotations. Set it’s value to 'True'.
   
   You should set the value according to the mount of physical RAM installed on your computer. Set value according to the following: (Installed RAM: 256MB / Set the value to: 4096), (Installed RAM: 512MB / Set the value to: 8192), (Installed RAM: 1GB / Set the value to: 16384), (Installed RAM: 2GB /Set the value to: 32768), (Installed RAM: 4GB / Set the value to: 65536) (Installed RAM: 8GB / Set the value to: 131072).

3. Step 3

   - - Method 3 - -
   
   (1)Launch Firefox then enter this, [about:config], without the brackets, in the address bar.
   
   (2)Scroll down and find entry that says: browser.sessionhistory.max_total_viewers, double
   click the item.
   
   (3)In the 'Enter Integer Value' text box, type in:
   "0" to disable the Firefox cache, change "1" through "8" to set the maximum cache; to "1" through "8" previously viewed pages, enter "-1" to return the cache to default. Enter value without quotation marks.

4. Step 4

   After reclaiming some RAM from Firefox, open the Task Manager while keeping firefox browser open. To access Task Manager:
   
   (1)Click 'Start'. Control Panel > Administrative Tools > Performance
   (2)Find the Firefox process on the current activity list, and view the RAM usage. You'll witness Firefox RAM usage drop dramatically.

5. Step 5

   According to lab tests, Firefox never seems to clear the cache memory it uses. It won't let go of memory until you close all windows Firefox. If you never close Firefox browser completely while spending several hours on the web, your computer will use nearly 1GB of accumulated memory during the session. If you feel a lag on your Firefox browser speed while online, then it might be a good idea to try the fix suggestions in this article.