Reduce Firefox Memory Usage when Minimize

We knew that Firefox has problem with the memory usage. Sometimes it can reach to hundreds of megabytes. But here is a tricks on how to reduce the memory usage when you minimize your Firefox.

  1. Type about:config in Firefox address bar and press Enter.
  2. Right click in the page and select New > Boolean.
  3. Type config.trim_on_minimize in the box that pops up. Press Enter.
  4. Select True and then press Enter.
  5. Restart Firefox.

What it will do is, when each time you minimize your Firefox, the memory usage will dramatically drop down to 10Mb (this is what happen on my PC) but then it will slowly increase up to 50Mb. When you maximize it back, it will stay on 50Mb or maybe 70Mb.

Note: This is only to reduce the Firefox memory usage when you minimize it. Not to fix them. 🙂 [via][tags]firefox, tricks, memory, software[/tags]


  1. Thanks! I think I’ll give it a shot!

  2. ok. tell me if it works or not. 🙂

  3. It worked like a charm! It went from 40 MB when freshly started down to 712 k and then rose up to 30 MB again when restored!

    Quite the handy trick there, now to see if there are any sideeffects…

  4. yea. i wonder what will be the side effects. but so far, it doesn’t give any problems to my comp. 🙂

  5. :d

    Works well. The first time I minimized it it dropped from about 45mb down to 18.
    After maximizing it and re-minimizing it dropped to 4mb.

  6. good to hear that it works on your comp man… 🙂

  7. Very useful specially with the Minimize to tray add-on. \:d/

  8. Doesn’t work for me. I’m on Firefox 2.0, and on Vista. I had two friends try it, too. One on Vista, one on XP. It didn’t work for either of them.


  9. [Comment ID #15215 Will Be Quoted Here]

    i will try the add-on later. thanks for sharing. 🙂

    [Comment ID #15280 Will Be Quoted Here]

    it should works. did you follow exactly the instructions given? 🙂

  10. [Comment ID #15284 Will Be Quoted Here]

    Yes, I followed the instructions exactly, and closed FireFox afterwards. After re-opening it, its memory usage is the exact same, be it open or minimized.

  11. i don’t know what could be wrong. it works fine on my comp. btw how about on your friend’s comp? still not working?

  12. Hmm, as it would seem, the XP friend was just a tad bit stupid and did it wrong. :-”

    I had another Vista friend try it, doesn’t work for him either. So, I guess Vista is incompat. Oh well.

  13. For more comprehensive list

  14. I tried it on Vista Ultimate 64 and it doesn’t work for me either. Guess it is incompatible.

  15. Robert Springer says:

    Nope still uses 250 mb of memory

  16. It doesn’t work on OSX 10.6.8