Quickly Minimize Memory Usage in Firefox (Without Installing Another Addon)

While there are tons of addons that you can install in Firefox to minimize its memory usage, sometime you may just want to use a simple method without installing yet another extension. Since Firefox 22 there is a native feature that allows you to quickly minimize the memory usage of Firefox.

1. Open your Firefox browser and type “about:memory” in the URL bar.

2. In the page that show up, you should see a “Minimize Memory Usage” button. If you hover your mouse over it, you will see a description of what it does. Basically, it will trigger a global garbage collection and flush the various cache.


When it is done cleaning up the memory usage, it will show a message “Memory minimization completed”.


That’s it.

Note: You won’t see any effect on a freshly open browser. However, on a browser that have been opened for a long time and has many active tabs, you should see that your Firefox is taking up lesser resources now.

Damien Damien

Damien Oh started writing tech articles since 2007 and has over 10 years of experience in the tech industry. He is proficient in Windows, Linux, Mac, Android and iOS, and worked as a part time WordPress Developer. He is currently the owner and Editor-in-Chief of Make Tech Easier.


  1. Does nothing in Firefox 23. As you said, this is maybe only for browsers before version 22.

  2. Works fine for me in FF 23. Is there any way to call this as an automatic scheduled routine? (just dont ask why)

    1. You might want to try out MemoryFox addon (https://addons.mozilla.org/en-US/firefox/addon/memory-fox/) for automatic memory cleaning up. However,it works only in Windows.

  3. Meh. It doesn’t really help that much.

    I just tried using all 3 of the free memory buttons on a FF instance I had open for about 45 minutes.

    It was using 1,015MB in task manager before. Afterwards it was brought down to 903MB.

    So yeah, that is a 12% reduction in memory usage, but I still do much better with the restartless restart extension. I keep a little restart button right next to my back button and hit it every once in a while.

    Same browser after a 3 second restart: 198MB.

    While I agree that it would be ideal if we could clear out the gunk in FF without an extension, it’s clearly not ever going to happen. I think it’s safe to say that most people who open and close any significant number of tabs have been wishing for it to happen since before 3.6.

    At this point, I actually use chrome about 2/3 of the time. Firefox is just for SEO work where I prefer a certain workflow and plugins. My newest laptop doesn’t have FF installed, which is good because it helps me not work too much when I’m supposed to be relaxing.

    So yeah, if you have to still use FF: restartless restart.

  4. Just got upgraded to FF 29 and the memory usage is much worst than previous version. It is more than double now with the same number of windows/tabs opened, right after fresh restart. So it is very slow and keep crashing now.

    I have 4 windows and 27 tabs opened. Before it is around 1.2GB and now it is 2.4 GB in memory.

    I have tried the “about:memory” tips but it only saved 100MB so it is 5% saving, not enough to help at all.

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