Editor’s Notes: These tips are for those users who are very new to Firefox. These are some basic tips and not the advanced ones.
Is your Firefox loading slowly? Or it just keep freezing up everytime you use heavy extensions or open multiple tabs? If yes, then you have come to the right place. In my case it can sometimes take up to 500MB of RAM when I open around 16 tabs and use a good number of extensions(yeah I am that geeky). Memory hogging is caused by the caching of pages and images for faster browsing. Now, Mozilla is working on fixing this memory hog in their next update. Hopefully, the next Firefox would have better memory management. Until then follow these simple steps to save memory.
Note: This tutorial is a bit outdated and does not show the real solution, however using “Fix Firefox Slow Start Problem” trick has proved to work for many.
Reduce Number Of Extensions
Cut down on the number of extensions used. More specifically, try to remove those extensions which access internet to update information for each site. If you want to know which add-ons are useful then check out our post on Best 5 Firefox plugins.
Disable Java Plugin
Disable the Java plugin, by going to Tools > Options > Content tab and unchecking Enable Java. Most sites do not use Java. So, you end up wasting CPU resources for a plugin that you do not use.
Open Fewer Tabs
Open fewer tabs. By this, I mean that you should not open more than 10 tabs. The more tabs you have, the more memory Firefox consumes. Experiment with the number and come up with an optimal number for your PC.
By following these simple basic steps, Firefox will help you save some memory. 
Share this article!
33 Comments
These are just stupid. Its like saying to reduce memory use an alternate browser. People choose firefox for the add-ons. It is common sense the more applications you run, the more memory. Telling me more tabs and add-ons = more memory is like telling me the sky is blue. And disable javascript is stupid also. Most sites *do* use javascript, unless your just reading news sites, which i am finding out is using java more and more
I see that there may be some confusion for people reading these posts. I just found out today that Java and Javascript are not the same thing*. I would guess a lot of the web uses Javascript code in their web pages. Java is a different computer language* and, who knows I am going to try to disable java in firefox for a little bit. Who knows it might just be helpful in keeping memory usage down.
*Here is a reference web site page for more on Javascript:
http://www.w3schools.com/js/js_intro.asp
Copyright 1999-2010 by Refsnes Data.
@anonymous coward
Thanks for going through this article. There are still people out there who own a low end CPU rather than an “everything inside” branded windows vista PC, this post was for those who want to use Firefox for its security purposes and still want to cut down the memory and CPU usage, we can always cut down our necessities, like we use a 3.2 MP camera phone and complain for its audio sound quality, we have increased our own necessities. When you open more tabs or open a new window u create different instances of Firefox which cause higher memory usage, in critical situation when you can’t afford higher CPU or memory usage you have to close some tabs, it may have become necessity for us, but not for everyone. So if someone does have a Low end CPU this post may help that person. You can visit our other posts, i hope you find them informative.
This is all very amusing, but years have passed, forum threads have opened and closed and opened and shifted and evolved and yada yada yada, and yet . . . Firefox 3.03 still has very high CPU usage, even after trying the latest and greatest KB fixes. One has to conclude that there is no fix, only yada yada yada.
Now Firefox’s forum is malfunctioning and won’t issue a confirmation number, making it impossible to communicate. LOL!
thanks Asad. (surfed in from search on this subject)
your advice tracks with my anecdotal observations.
700mHz; running: windowsXP, firefox, comodo, avira; 385 RAM; average hard drive… I’m always looking to run lean.
I do wish there was a site that provides analysis on all these add-ons (better than trusting comment sections at download site.) I totally enjoy the multitude of add-ons, but have frustrations in not knowing the memory, cpu, or “phone home” aspects.
Another BIG issue for me is knowing that users around the world are not discarding perfectly usable machines. I encourage developers and performance oriented geeks to think about this and give greater considerations to issues of backward compatibility.
hey, stopped back to provide further info on that “phone home” activity w/ Firefox and add-ons.
http://support.mozilla.com/fr/kb/Firefox+makes+unrequested+connections
Probably not a big issue on the resource thing, but FYI if you watch such things and are curious.
Thanks lolTech for understanding and appreciating … the link u gave is an extremely great find, i didn’t know about it .. thanks for sharing it with everyone.
How to increase the speed of your computer…
Throw it from higer place…
hi,
may be this link will help, it helps me a lot especially on ‘prefetch’ things.
http://support.mozilla.com/en-US/kb/Firefox+consumes+a+lot+of+CPU+resources
Just a note for “anonymous coward”, you referred to both JavaScript and Java in your post. I may be wrong, but I got the idea you think these are the same thing.
JavaScript is a simple text-based script that can simply found in a page’s HTML… It doesn’t require any more RAM/CPU than HTML, CSS, PHP, etc.
Java, on the other hand, does require more. Java, by comparison, would be more similar to Flash, in this case. It’s more than just text, it’s actually like a small application.
Just clearing things up.
Thanks for the article.
replyer said: “JavaScript is a simple text-based script that can simply found in a page’s HTML… It doesn’t require any more RAM/CPU than HTML, CSS, PHP, etc.”
I don’t even know where to start pointing out what’s wrong with this statement. First of all, PHP is server side, which makes it completely irrelevant on the client-side. Second, how much RAM and CPU javascript uses greatly depends upon what it is that the Javascript is doing. If somebody has Javascript on their site doing anything flashy, in Firefox, that will cause the CPU usage to spike awfully close to 100%. The amount of RAM it consumes is also tied in to what it is doing. Although it is true that the script itself doesn’t consume much, what it is producing may cause a lot of RAM to be used (if it’s dynamically generating HTML, or simply creating JS objects it’s not letting go). Heck, I’ve been monitoring my FF lately, and I’ve noticed that a page with Javascript constantly animating something will leak memory. Which means if I leave it open, pretty soon it’ll consume 100% of my memory. It’s very slow but it’s definitely there. And that, of course, depends entirely on the JS engine in use. In this case, the one FF is using has major flaws.
So, my point is that Javascript will use as much CPU and RAM as any other application if A) it’s written poorly, or it’s heavy by design OR B) the JS engine has flaws.
wow thanks for these tips, i’m sure some newbies on the web will surely benefit from it
Thanks for the post,, it was the stinking java that was slowing down firefox.. 100% cpu… Thank you so much for posting this, BTW im an advanced user.
Well 500 MB of RAM used by FF its not much, my record is 850MB/1GB DDR 333 (14 plugins, 27 extensions, and about 20 tabs
- Speaking of Firefox problems – the only problem I had – Firefox suddenly started using 100% CPU – I done system restore – it helped – but then recently it started doing it again – consuming 35% – and I found this solution – done exactly as it’s advised – and now my Firefox uses 10% CPU.
1. Open Firefox.
2. Type ‘about:config’ into the address line and hit Go or return. This takes you into the Firefox expert config menu.
3. See if there is an entry called browser.cache.disk.capacity.
* Yes? then modify the value to 16384, close Firefox and restart Firefox. It’s fixed.
* No? right click somewhere on the about:config page and select Integer. Create an Integer entry called ‘browser.cache.memory.capacity’ and set it to 16384. Close Firefox and restart Firefox.It’s fixed.
4. Check the CPU and memory size by ctrl-alt-delete and select the Performance tab… look for the firefox.exe process and the CPU for Firefox should now stay nominally under 10%.
Here is a link people should take a look at. I thought some of the tips and insights were helpful. It’s Mozilla’s own knowledge base of solutions in regard to this high CPU usage issue. http://kb.mozillazine.org/Firefox_CPU_usage.
BTW, has anyone else tried Andy’s advise successfully?
Fix I found and WORKS…
The fix for Linux was to change the default value of the parameter Urlclassifier.updatecachemax from -1 to 104857600. The -1 value for the maximum cache size means unlimited and is the default value for all other operating systems while the value for Linux has been set to 104857600 which is 100 Megabyte.
Have a good day
I tried Andy’s fix, but Java is still 50% usage on a new dual core computer
this is just stupid.. the person who wrote this doesn't seem to realise that java and javascript are 2 completely different things, ALL websites use javascipt in one form or another, weather that be actual javascript or ajax or jquery or similar, it's in there and improves the functionallity of any site, turn it off and the web becomes totally unusable, next you'll be saying to switch off cookies! if you do that then you won't be able to buy anything that requires you to add products to carts etc!
This post is rather silly. The screenshot for disabling Java shows JavaScript disabled.
This post is rather silly. The screenshot for disabling Java shows JavaScript disabled.
This post is rather silly. The screenshot for disabling Java shows JavaScript disabled.
Most sites still do use java
This can also be done with tools->options->advanced->network set offline cache to 16mb.
“Most sites do not use Java. So, you end up wasting CPU resources for a plugin that you do not use.”
In what world are you living??? Most MAJOR sites now use javascript to manage DOM objects and create client side effects!!
Tried Andy's fix (or rather Vic's variation) … doesn't work.
Why don't just not use Firefox. That's basically what you're suggesting we do in this article. Turn everything off and only use one window. Why not just download Mosaic, if you can still find, and use that? Another non-answer on the Internet.
Im getting so bored with Firefox now days:/ when I started using it, it was lightning fast!
now it seems it’s just as blotty as internet explorer,
why can’t they just keep it simple and fast?
I really need a fast and light browser
because I am one of those with old hardware
Ever heard about Google Chrome?
I’ve not tried it yet, but you may be interested in checking uzbl.
I just found this post through google. Firstly I have to point out that the first and most of all the last advices are not tricks but plain common sense : if you put 500kg of lead in the trunk of your car, chances are that it will not go faster.
However, the second point (neglecting the confusion between java and JavaScript, or at least the text/image mismatch, which lead several people to miss the point), seemed quite thrilling to me, so I made a few tests. Here is the conclusion : unfortunately, the effect of disabling java is at the least completely negligible, even with a not so young computer. Actually I did not see any effect at all.
Concerning Andy’s suggestion in the comments, you can find more informations about the key he is referring to at http://kb.mozillazine.org/Browser.cache.disk.capacity but honestly I don’t think it should have a huge effect since it mainly affects the disk usage. I would rather consider the following key, which is not related to the CPU usage either but to the memory usage, which is also critical : http://kb.mozillazine.org/Browser.cache.memory.capacity
I do agree with your pointers and would like to point out some other items I have listed on my site. They are in wiki format so no comments can be made there but your visit and use will be enough. I will be adding more in the near future so keep checking back.
http://fiwebelize.com/wiki/index.php/Tech:firefox
Here is an article with some advanced tips for resolving high CPU issues
http://www.bukisa.com/articles/328432_100-cpu-how-to-fit-it-a-complete-troubleshooting-guide
2 Trackbacks
[...] http://is.gd/xagQ [...]
[...] http://www.addictivetips.com/windows…-memory-usage/ hope these help! __________________ Google Chrome ClubThe Samsung Owners [...]