Firefox Only: Memory Fox constantly recovers RAM/memory wasted by Firefox

As great of a browser as it is, Firefox is probably the most notorious memory leaking software known to man to date. With no time to spare, a user can easily be losing dozens – often hundreds – of megabytes of memory to Firefox. To help address this memory issue, I have talked about CleanMem in the past, one of the most effective and useful memory cleaners/optimizers/whatever-the-heck-you-want-to-call-it. Memory Fox is a program that does similar things as CleanMem, except Memory Fox is a Firefox add-on that is focused specifically on Firefox memory usage.

How Memory Fox works is simple. Whenever you switch from tab to tab or create/close a tab, Memory Fox flushes the memory used by Firefox, similar to how CleanMem flushes memory used by all programs every X minutes. Memory Fox also flushes the memory used by Firefox if Firefox is idle. However, while CleanMem is only “on” every X minutes (when it needs to do its job), Memory Fox is constantly running while you have Firefox running. The good thing is, though, Memory Fox itself does not use very much RAM/CPU (~1.5 MB RAM and 0-1% CPU) so its own process (called afom.exe) won’t impede on your computer resources.

According to the developer of Memory Fox, Memory Fox “focuses on two (Working Set and Private Working Set) types of memory usage and with flushing for memory recovery. When resource requirements (Stack and Heap) have been reached, according to the user’s preset option settings, the memory will be flushed and recovered from Fragmented Orphaned Ram memories.” That is just a mouthful and geeky way of saying Memory Fox will help mitigate Firefox’s famous memory leaking problem.

After you install Memory Fox, you need to manually enable Memory Fox…


…and manually set it to automatically start on Firefox boot:



Overall, while Memory Fox won’t *fix* Firefox’s memory woes – you can’t ever fix the memory problems of a program with a third party program – it does a great job at keeping it in check. You can get Memory Fox from the following links:

Supported OS: Windows XP/Vista

It also works just fine for me on Windows 7.

Version reviewed: v1.01

Memory Fox homepage

[Download page]

***NOTE: Because Memory Fox is a new add-on, it is temporarily marked as an “experimental add-on” at Firefox add-on’s website and you must check the “Let me install this experimental add-on” box to install it. As far as I am concerned, Memory Fox is fairly stable so there is no worries there.***

[via Ghacks Technology News]

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  • jumbi

    its new homepage is:

  • Squall


    Memory Fox’s purported Memory leak and freeing capabilities are a lie. Memory Fox uses a standard windows function to flush the process’s memory to the page file RESULTING IN WORSE PERFORMANCE.

    Any windows developer with an ounce of free thought will realise in an instant that the claims made by the extension author are bogus and the experiences of its users are placebo. Firefox’s stability and memory use will differ from session to session, and even between reloadings of the same session, and especially differ between Windows sessions.

    The only extension which actually effects real memory usage is the ramback extension which flushes the System memory allocated caches.

    Anyone seeking to verify this, can enable the Commit column in task manager or use about:memory.

    This review will be going viral.

  • Mobius


    My bad! I found AFOM during a search that, at the time, did not show Memory Fox. I just now did another search and found Memory Fox, and saw that it has been updated more recently, although it is Experimental, so that makes AFOM still the Primary addon. So, my half-bad :-)

  • Ashraf

    @Mobius: How so? Memory Fox is not AFOM now; AFOM is the predecessor of Memory Fox.

  • Mobius

    Memory Fox is now AFOM.

    Version numbering is confusing.

    AFOM is up to version 2, but supports the current maximum release of FF which is 3.6.

    Read the notes!

  • Kent

    Apparently Memory Fox is gone or has been re-named. The link above is dead by the way. I did find an add-on called AFOM Memory Recovery and Retention which reads the same so I’m betting on the name change.

  • Wheezer

    When I tried to add Memory Fox to my new computer a couple minutes ago, I couldn’t find it in the “Add-ons” in fire fox.

    So I came here to try the links in the post. The direct download link gives a message saying add-on not found. The link to the Memory Fox Homepage takes me to a page that says “The blog you were looking for was not found.”

    I don’t know what’s going on for sure, but it looks like it’s been discontinued. ???

  • Emrys

    Very cool. saved 5% right away….thanks again for your service to us. I forwarded your link to my FF friends.

  • Dave

    Without a doubt, one of the best plug-ins for FF. Thanks for the HU, Ashraf…this is the stuff that makes this site worth visiting every day.

  • Ralph

    As I keep Firefox permanently open I thought Memory Fox would be a great idea. I also have the “swap to virtual” setting as suggested by Locutus.
    But since installing Memory Fox I’ve found that Firefox hangs when it’s been minimized for a while and running scripts fail.
    Could be just co-incidence but I’ve disabled it to see. . .

  • Helen

    Installed Memory Fox and FF hasn’t become cludgy since. Thanks!

  • Sandeep

    @ Ashraf:

    I installed Memory fox as per your instructions but on clicking and activating it gives an small dialog box “AFOM Monitor” with a OK button. Not sure if i m missing something or this is the way it works.

    Thanks Ashraf.

  • ton


    Thank you so much Ashraf.

  • Giovanni

    Hey Ashraf!!

    I have recently stumbled upon a little tool called “Firefox ultimate optimizer” that, according to his developer, should reduce the FIREFOX memory usage of about 90%…and guess what??

    After starting this program the RAM usage of my Firefox browser dropped from 100 MB to 2 MB in a few second times: can you believe it?? UNBELIEVABLE!!! LOL!

    The only drawback I noticed is that it increases the CPU usage quite a lot, probably because it puts more of the memory on the hard drive instead of the RAM itself.

    So it looks perfect for PC with low memory resources and a good and quite fast CPU running in it.

    What do you make of it, Ashraf??

    Had you ever heard about this tool before?

    You can download it here:

    For more information please read the following short article wtitten by your friends of “”:

    Please be aware that it requires .NET Framework 2.0 to work properly!!

    Alternatively have a look at this compelling article and let me know what you think about it:

  • @Ashraf: I agree for the most part but whether because of trying to do both or because they aren’t as controling in the end with MS theres less control over you, your computer, and your data.

  • Ashraf

    @Samuel: On a scale of control freaks, with the left being computer, and the right being data, Apple would be on the far left, Google on the far right, and Microsoft in the middle… because Microsoft wants to do both but just isn’t as restrictive/as large as the other two in their respective freakishness =P.

    @Ton: I assume you mean the bar at the bottom of Firefox and not your Windows Taskbar. If so, ya that is how it is supposed to be. Just be sure to enable it as per my instructions above.

  • Ton

    Hi Ashraf, I am a frequent visitor to your site and I am learning new things from you. I have installed Memory Fox and I notice there’s a green icon of Memory Fox at the taskbar. Am I doing it right?

    Thank you.

  • @Locutus: so you want to change one control freak for another? not say MS is better just pointing out that both Apple and Google are control freaks. Apple the computer, Google your data.

  • @Samuel: Ahh, but the iPhones are the things I complain about. Seriously? Google Voice not on the iPhone? Ha ha ha Apple now APPROVE IT!!!!

  • @Locutus: A vaild point but at the same time Apple is usually safe behind a wall of iPods and iPhones, so they’re “safe”.

  • @Samuel: Ehh, I find bashing Apple for their closed systems and their users’ lies about not having viruses more fun.

  • @Ashraf: More like Microsoft IBM (Internet Ballistic Missile).

    That is true, but being as Microsoft is now the same as evil to most geeks they bash it while forgetting some of their good points.

  • Ashraf

    @Samuel: Samuel, our resident Microsoft bouncer. JK =P.

    On a serious note, both IE and FF have their own pros and cons. Anyone that blindly makes fun of one browser is doing just that: blindly making fun of one browser.

    @Albi: You are welcome; glad it helps.

  • Albi

    Thanks a lot for this. I just installed it after I read your review. I can tell you that it works, and it works great.

  • @Ashraf: Hey, someone’s got to defend IE :D

  • Ashraf

    @dojo: I’ll take that as you will be using this add-on.

    @Locutus: Cool. Thanks for the tip.

    @Samuel: You know as I was writing this article, I knew you would comment on how IE doesn’t have this problem =).

  • And as a happy IE user I don’t have this problem (argue all you want that IE doesn’t have add-ons but I’ll take a product that doesn’t need a third party app to make it work right over an app the does).

  • Also, if you set config.trim_on_minimize (in about:config) to true then it’ll transfer itself to virtual memory on minimization.

    Changing this would help too:

    This should interest you:

  • dojo


    That is all.