Firefox CAN be faster – 4 easy tricks

February 6th, 2007

Now that we all know the hidden pages in Firefox, it’s time to go a bit deeper into tweaking your browser for optimal use. All of the operations will be made in the about:config page, so save your important stuff, open up a new tab, write about:config in the address bar and be prepared. I have gathered four tricks that will improve your Firefox experience, and here they are.

1. Fetch only pages that you click
Firefox mostly resembles to Google from this point of view. It has a built-in feature (enabled by default) that will pre-download the pages behind the links it thinks you MIGHT click. Google anticipates you might click the first result from the page, but how in the world can Firefox anticipate the link you’re going to click? Anyway, in my opinion this is just useless bandwidth usage, CPU power and HDD space. You’re practically downloading and storing pages you are not viewing. Here’s how you stop that in three simple steps.

In the about:config list, filter up your search after ‘network’ so it would be easier for you. Then, find through the remaining list options the key that says network.prefetch-next. It should be set to TRUE. Double click it, and it will turn to false. There we go, now Firefox will stop acting creepy and will only fetch what you click ;)

2. Limit the RAM usage
Although it’s not taking up THAT much memory as other browser, shortly, it still does. But you have a way to control that. It’s just a simple configuration setting and you’ll get the numbers to be more comfortable. Filter up your search after “browser.cache” and select browser.cache.memory.capacity from the remaining options. I believe the default setting goes all the way up to 50000, but there’s no need for that. You have to adjust the value depending on the amount of RAM memory you have installed. For RAM sizes between 512MB and 1GB, start with 15000. For RAM sizes between 128MB and 512M, try 5000, and you will be happy of the result.

3. Reducing the RAM usage even more when Firefox gets minimized
I got an extremely low usage on this one. Somewhere around 10MB, so it’s definitely a must-do. Basically, this will move Firefox to your hard drive when you minimize it, and as a result it will take up much less memory. It won’t even go back to the same high usage after you restore it. Even if Firefox will be located in your HDD instead of your RAM, I can assure you the restoration speed will be the same, with no delays.

All you have to do is right click your about:config page, select New and click Boolean. A box will appear and you will have to enter config.trim_on_minimize as value. The boolean value should be set to TRUE in the next screen, and that’s it. Test it after restarting Firefox.

4. Make pages load faster
Most browsers are configured for dial-up users. Tweak the settings for your optimal use. Filter out the list after “network” then search for the key that says network.http.pipelining and set it to TRUE. You may alter the key below (network.http.pipelining.maxrequests) and change it into a higher value – 10 for example. Voila, your pages will load much faster now.

This is just about it, and if you guys have any other tricks for improving the Firefox experience, we’ll be glad to hear them.

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  1. Nuno:

    Just for saying that in the Linux version of Firefox, instead having #browser.cache.memory.capacity# you have #browser.cache.disk.capacity#. It works the same.

    Keep up the good work. ;)

  2. Online Apps:

    I like it. The only one I wouldn’t do is #4. First of all, Firefox can only do up to 8. Second, it’s really rude. If everyone did it, it would crash servers everywhere. Because of this, servers may even block you from visiting the site.

    I would replace 4 with the OpenDNS. Faster, adds security, and fixes typos. Will also work with IE, Opera, and anything else that connects to the Internet.

  3. Jack Sloan:

    Where do i Filter up your search as in # 2

    can anyone help me ?

  4. Bogdan Boghiu:

    You just type “about:config” in the address bar and the whole list shows. There’s a small box on top, that allows you to enter a filter word.

  5. Pontus:

    Number two can be done in Firefox’s Settings dialog, under Advanced > Network, although there the value is divided by 1 000.

  6. wolfen100:

    I tried to find : ll you have to do is right click your about:config page, select New and click Boolean. A box will appear and you will have to enter
    config.trim_on_minimize as value. The boolean value should be set to TRUE in the next screen, and that’s it. I can not find where I can right click on about:config page. Maybe I’m not as smart as you.

  7. lucasrangit:

    wolfen100: right-click on any of the entries in the list and select New -> Boolean.

  8. cill:

    wondering if u could fix layout?? make “3. Reducing the RAM usage even more when Firefox gets minimized” bold… was a bit confusing – thought i was still reading number 2… thanks!

  9. Bogdan Boghiu:

    I got it fixed ;)

  10. windwalker7:

    One of the things driving me insane is Firefox’s bookmarks. It is like Chaos in motion.

    In Opera and IE I have a vast collection over 10,000+ I have figured out how to sort the and categorizes my bookmarks very well.

    However, in Firefox (which I have say I have just fallen in Love with except for this annoying problem) I create a sub folder name it something come back later on to add to this sub-folder again and I spend 2 hours searching every where to find it again.

  11. Frank Schreiber:

    Online Apps,
    Please explain how to use OpenDNS in place of #4…. Thanks.

  12. Sam:

  13. Bogdan Popa:

    @Frank, just configure your internet connection to use the OpenDNS servers ( and instead of your default addresses provided by your IPS.

    On the other hand I find OpenDNS to more of a nuisance, the loading time is not significantly improved and on the other hand you get loads of ads if you misspell a URL.

    @windwalker7, there are some really interesting plugins for Firefox to manage your bookmarks.

  14. Dennise:

    I’m loving these, easy to understand, great results, I love it! thanks!

  15. Tina:

    Right-on…Helps alot, thanks so much:)

  16. Chris:

    Check out this site. It has 13 additional tweaks that you do to improve firefox’s surfing experience.

  17. Phillip:

    Good stuff dude. Hope these work as well as you say they do. You might want to alter the first paragraph and tell people to type the about:config in the address bar. I was lookin through the Tools>Options menu for a WHILE, until I scrolled down to see if there were any comments aboutt the page.

  18. Pike:

    Great article, I got some stuff out of it that I didn’t know about previously… thanks for the tips.

    Nuno, thanks for telling us Linux users about the difference!

  19. Bogdan Boghiu:

    @Phillip: Well, it does say in the introductory paragraph: :)
    “open up a new tab, write about:config in the address bar and be prepared”

  20. James:

    Hi. Nice article. You should clarify one important thing though. Tweaks 1-3 don’t make Firefox itself faster (in fact they slow it down), but instead make your overall computing experience (if you are multitasking) faster by ensuring Firefox takes up less resources (RAM, CPU Cycles, Hard Disk read/writes for caching, etc.). If you usually aren’t multitasking with other programs that need lots of CPU attention/RAM, Firefox /will/ run faster if you allow it more resources and don’t apply 1-3. I’ll note that pre-fetching is disrespectful to servers though, and on low-RAM machines (256 Mb), you may still want to trim Firefox’s RAM usage so that the OS is never affected.

    And to Online Apps, OpenDNS is great, just be sure to benchmark first, as “faster” depends on the ISP. For example, some college campus DNS servers are lightning fast and OpenDNS will actually slow you down.

  21. Butch:

    Well, my Win version of Firefox has both, which probably means your Linux version has both as well, and you just didn’t look carefully enough. And no, they don’t work the same.

  22. Hen:

    Bravo on the TWEAKS!! They really work but you people should be on a broadband connection to get the most out of these tweaks…..

    I might be wrong but i might not be wrong.

  23. JB:


    Tip number 4 is certainly most beneficial to broadband users, but numbers 1 to 3 could be of benefit regardless of your connection type.

    Cheers JB

  24. Leon:

    Great tips! Though only two of these tips are new to me, thank you nonetheless.

  25. yep yep:

    The easiest way I have found to make Firefox a lot faster was to mod the pipelining settings with this guide it goes like a rocket now :)

  26. Brian:

    @Bogdan Popa: Don’t mess up the URLs and you won’t see ads from OpenDNS. Easy fix.

  27. benny:

    You should really add the thing Nuno said to your post: “Just for saying that in the Linux version of Firefox, instead having #browser.cache.memory.capacity# you have #browser.cache.disk.capacity#. It works the same.”

  28. steve:

    I found some other ways to speed up firefox

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