One of the most common problem with firefox is memory usage especially if you don’t have enough ram on you system, usually i open two firefox window and sometimes i open like 50 tabs and more when i check firefox memory usage i find it something like 550 MB, although i’v 4 GB ram in my system , i noticed firefox become slow and it’s really annoying, so i tried to search and find how to redue firefox memory usage and i found these tips to solve this problem.

1-Limit Pages Stored in memory
Every time you visit new page firefox store it in memory to help improve performance and load pages faster when back and forward

1. type about:config in the address bar
2. search for this string browser.sessionhistory.max_total_viewers
3. the default value is -1 you need to change it to 0

2-Reduce memory usage when minimize firefox

This will reduce firefox memory usage when minimize and let Windows to claiming back the memory used when it minimize.

1. Type in about:config in the address bar
2. Right click and choose New > Boolean
3. Type config.trim_on_minimize in the pop-up box and hit Enter
4. Select True and hit Enter.
5. Restart your Firefox

3-Fixed cache capacity

Evey time you visit new page firefox will cash this page in memory so it doesn’t need to be loaded again when you visit it later.

1. Type about:config in the address bar
2. search for this string browser.cache.memory.capacity
3. If you set to 0, Firefox will not cache any pages. for more info read here.

4. Use less extension as possible

Try to use only important extension you really need dont install extension you not going to use it, this will herlp you reduce firefox memory usage.