Wednesday, May 27, 2015

How to reduce Firefox (FF) memory usage?

How to reduce memory usage in Mozilla Firefox


Know your browser

Type about:memory in the Firefox address bar. This will show you current memory usage.

Browser history

  1. Type about:config in the Firefox address bar
  2. Do a search for browser.sessionhistory.max_entries
  3. Double click the default value (50), change it to something lower (3, 4, 5).

  1. Type about:addons in the Firefox address bar 
  2. Disable unused/unnecessary/unknown addons and plugins

AdBlock Plus

If you don't have AdBlock Plus, you don't know what you are missing: The Internet without ads!!! I am not kidding! However, it was reported that AdBlock Plus increased memory usage. So, if you have lots of open tabs, you may want to disable this plugin.
I did an experiment in May 2015, and it seems is not true, or at least, they fixed this issue, since then.

Enable hardware acceleration

  1. Type about:preferences#advanced in the Firefox address bar
  2. Check "Use hardware acceleration when available".
Please note that in my case this creates other (font-related) problems.

Restart Firefox often

In my case it helps a lot to restart Firefox every hour.


Press Ctrl+H to show the 'History'. Delete all entries older than 6 months.

Install it fresh

Installing a fresh copy of Firefox will help a lot. Somebody made and experiment about this here:

In my case, the memory consumption decreased from 900MB to 500MB.