Firefox 3 Hogs Memory Like Crazy

by David Risley on Jun 4, 2008 | 94 comments

When Mozilla released Firefox 3 as a public release candidate, it was supposed to fix a bunch of memory leaks and use less memory. In fact, it reads:

Memory usage: Several new technologies work together to reduce the amount of memory used by Firefox 3 over a web browsing session. Memory cycles are broken and collected by an automated cycle collector, a new memory allocator reduces fragmentation, hundreds of leaks have been fixed, and caching strategies have been tuned.

Technical, yes. Real? Not really. While I have heard from others saying that Firefox 3 is running lean and mean for them, I have heard from many others saying it is just as bad in the memory department as Firefox 2.

Check out this screenshot from my own Mac Pro running Firefox 3:

Yes, that’s 550 MB of RAM in use.

Now, I’m fully aware that the plug-in functionality of Firefox can lead to this issue. It is non-Mozilla code which is in use in the browser. But, I used pretty much the same selection of plug-ins with Firefox 2 as I am now with Firefox 3 and this is about 150 MB more memory than I had ever seen Firefox use previously.

Plus, if you have to steer clear of plug-ins to keep Firefox running correctly, then that is a stupid tradeoff. One of the primary “selling points” of Firefox is the ability to use plug-ins.

I have tried the RamBack plug-in. It shaved maybe 12 MB off the memory usage, but who cares. For all essential purposes, it doesn’t work.

I’ll continue to use Firefox, but thank God I have a bunch of memory in this system. Looks like I’m going to need it.

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greg
I’d suggest if you really are having problems with FF3, when was the last time you’ve cleaned your system? Files may be corrupted. Left over dll files from uninstalled programs loading in the background from a bad uninstall, plus many other hidden problems. Sometimes its best to backup and do a full reformat and install if you are using XP. It might help for Vista as well. Sorry, not a MAC user so I don’t have any advise other than to sell it and get a PC.
Lapax
Wow, I thought I was the only one as well. FF3 is using waaaay too much memory with me as well. I’ve just got 3 plugins and hardly use more than 5-6 tabs. Even when you exit it still keeps running. Then I use procexp to kill it and its there I can see how much memory its using up.
Sadly I’m back to FF2 now.
Indrit
I have seen this problem on my pc too
xopht
I’m using FF3 on my PCs(Home & Office) and I have same problem too. Sometimes, FF3 is freezed and only one tab uses more than 200mb.
I’m considering switching to IE seriously…
Abhinav Kumar
I have tested all three browsers. I left Safari bcoz it is universally known that Safari is a memory hog on Windows.
Firefox 3.0 | Internet Explorer 7 | Opera 9.51
Test 1:
Tabs Opened:
Yahoo
Yahoo Answers
Orkut Home>Orkut Scrapbook (> means navigated)
Orkut Communities
Browser: Memory/VM Size
Firefox: 63 MB/58 MB
IE: 95 MB/101 MB
Opera: 71 MB/75 MB
Test 2
Tabs:
Digg
A Java Chat Applet
Computer World
Mozilla
Opera
Microsoft
MSN
Skydrive
Symantec
PC World.com
PCMag.com
Facebook
MySpace
Firefox: 162 MB/170 MB
IE: 292 MB/344 MB
Opera: 207 MB/246 MB
Test3: (Silverlight)
Microsoft Silverlight Showcase (silverlight.net)
Firefox: 42 MB/43 MB
IE: 49 MB/56 MB
Opera: Not Supported
CPU Usage.
while viewing a Youtube video (Adobe Shockwave Flash Video)
F: ~20%
IE: ~25%
Opera: ~45%
The best way to prove something is to test yourself.
You can test yourself by opening these pages.
Don’t forget to enable VM Size column in Task Manager. VM Size shows how much resources the program is actually using.
During Test dont ever minimize any windows.
R. Decher
So I got sick and had to acknowledge that Firefox 3 has become a memory hog.I googled “Firefox 3 memory Hog” and it led me to this site.
I am a mac user, and I preferred Firefox over Safari, due to its add ons. Nevetheless I usually navigate using Firefox, Safari and Opera simultaneously, and with multiple tabs. And guess what, my machine handled them nicely when Firefox 2 was installed.
Now with Firefox 3, the fan just goes nuts, and when Firefox is running at 110% I have to turn it off. Safari and Opera remain stable, which pisses me off, since Firefox is still my preferred browser. I have a feeling one of the add ons is messing things up.
this is my list of add ons:
delicious bookmarks, forecast fox, downthemall, readitlater, gspace, foxclocks, and a couple of dictinaries.
Regarding the review : i think using 500% is exaggerated. I would fear my machine would blow up beyond 250%, so I think you are pushing it up deliberately and suspiciuosly to state a point. Nevertheless, the point valid.
R. Decher
started happening again a few minutes ago. Only had two tabs open, but one was : thesixtyone.com
turned the tab off and … voila!
Nevertheless annoying.
http://dragffy.com Gabe
I came to this site after realising that my computer had been slowed down by FirFox 3.
I can’t believe the hostility that your post has received. You had a bad experience with FF, you even got a screengrab and wrote about your disappointment, which then received undeserved criticism that your post wasn’t scientific. I don’t use FF in a scientific way, I go to sites that I want when I want, if it was tested in a scientific way the results wouldn’t be accurate for real-world usage.
Anyways, I checked Activity Monitor while writing this, with FF consuming 615MB RAM, with two tabs open (yours, and campfire). I took a screengrab which can be found here: http://dragffy.com/blog/wp-content/uploads/2008/07/ff3_memory_uasage.png
As you can see I have web developer extension installed, I also have Firebug and Foxmarks installed. Nothing spectacular. Firefox has now been open for about 50 hours. But *I know* if I restart wihtin a couple of minutes it will already be exceeding 200MB, then grow and grow.
I’m running OS X 10.5.4 on a first gen Macbook with 2GB RAM.
I have seen consistently good reviews about FF3 on the internet, beating it’s competitors in memory usage, but that’s mostly been for Windows. I think that there is something seriously wrong with the OS X build.
For me FF3 is slower in all departments than others such as Camino, Safari, and Opera. It feels sluggish and bloated. So much so that when I visit lengthy web pages such as Django’s API pages the scrolling becomes snail-slow and jerky. Camino also exhibits this behaviour leaving me thinking there is something wrong with the Gecko engine (on OS X). Safari and Opera let blitz through pages on the web just fine – but then Safari doesn’t have Foxmarks, and Opera is butt ugly (on OS X), and none have web developer of firebug extensions – something I have come to rely on.
Keep up the good work and funny captions on your screen grabs!
BTW, just before I wrote this FF was actually consuming 650MB RAM, for some reason it dropped.
http://dragffy.com Gabe
Mentioned in a previous comment that I found Firefox slow and cumbersome when scrolling through long web pages. I get this on all me Mac computers. Don’t know what it is like on Windows though. Perhaps some people reading this can test by visiting: http://www.djangoproject.com/documentation/db-api/
Just scroll down the page. If you have the same problem as me the scrolling will be juddery and slow and generally unpleasant.
can’t believe I can’t even scroll a lengthy webpage without performance suffering, this is one of the most basic things of web browsing. Also wanted to note that during such scrolling CPU usage hits 100% for one of the two CPUs in my computer. This is appalling, by the same token safari is smooth and consumes about 20% of one CPU – a fifth of firefox!!!?? WTF is wrong with FF?
cxspan
I didn’t read every single comment, but I’m pretty sure I have everyone beat. With 4/5 tabs open and 7 add-ons, I hit 1.3Gb of usage on an XP Pro system with FF3.0.1, and 50% cpu utilization. I have 2Gb of memory and between FF and iTunes my computer was all but dead in the water. This only appears to happen after FF has been open for awhile, even if I am not actually using the computer. I do suspect it is an addon causing the issue and I will uninstall them one-by-one until I find the culprit. Also going to check out that Firefox Ultimate Optimizer that Brian mentioned. I still think FF is the greatest.
Thanks for the post. I am curious, by now you are probably not running the RC version. Have your figures improved since?
Emi
Well, how should it be explained if I opened only google, no tabs, and it took 103MB memory after I started firefox for a short while?
Matt
I decided today to stop using Firefox 3 when I came home and found it had gobbled up 1 GB of memory. At work where I’m a web developer I and my colleagues have found the same thing. It just eats and eats and eats. It’s like we’re back to the IE6 days or something.
steve
well theres your problem right there. your using a mac. dont use a mac and you wont have any problems.
elprrrrrra
hi idk wtf is happening with mine mozilla too the other day i was playing runescape and hearing music on youtube and it almost get to 900,000kb i was like wtf?! it aint supposed to be that much and when i just run it and get on google its get 70mg by the way i am using windows vista homepremiun 32bit x64…. ty ill be watching for solutions
Jake
I have the same problem! Even when I close ALL the tabs, FF still consume over 200 MB. I have to restart FF every few days when it reaches 800 MB.
I also see FF consume a lot of CPU if left running for a week. Maybe it’s Flash that’s eating CPU…but there should be some sort of way to stop that from happening. Maybe something that helps me find the memory leak, and CPU leak. It could be FF, plugin, webpage, or something else.
Jake
My scanner says “Firefox Ultimate Optimizer” is Adware.
Any other recommendations?
frenchuser
Hi ! I don’t know if you’ve finally solved your problem – I give up reading after twenty angry coments ;°) but…
You are not alone, David Risley…
I actually have an I Mac Intel Core 2duo 1Go Ram, running on Mac Os X-5-5.
I download FF3.0.3 less than a month ago because I was fed up with the constant bugs I encountered with the last version of FF 2 (2. something)
I use it the same way I use FF fom the begining : two or three pages opened with at least 8 tabs on each is a minimum (my record – without intents – is about 80 tabs on a total amount of seven or eight pages).
At the time when I’m posting (7 pages, 62 tabs) : the activity monitors says : 569,11 Mo MR & 2,47 Go Virtual memory !!!
However, I have to say that even with a single page opened and a couple of tabs, I quickly reach the same level of incredible activity. Actually – should I say “fortunately” ? – it seems to stay at this level whatever the (ab)use I do with…
Problem is internet seems rather silent about this trouble, exept with articles talking about the beta version and nearly a year old…
To conclude, I should point out that the firts versions of FF, around 1.5, let’s say, was running much smoother in comparaison. I think ‘I’m going to forget it and keep tight with Safari instead, even if FF is better designed.
frenchuser.

Jake McCrary
I’ve been using the Firefox addon RAMBack for a few weeks. It seems to have solved the memory problem.

Moe
YEP, me too. No probs with FF 2, but ever since I upgraded/DOWN GRADE to FF3, my CPU just locks up after 1.5 hours, and I make sure to NEVER open more than 3 tabs…usually only 2. I am sick of having to REBOOT but IE does not allow me to log in to my remote email server anymore??
A google search for this problem, led me to here. I thought I must have a virus. Your earlier “posters” from 06/08 are cry baby douchebags.
Hope someone from FF googles this too!
http://vba-m.ngemu.com/forum Squall Leonhart
as i posted here http://neosmart.net/blog/2008/firefox-3-is-still-a-memory-hog/comment-page-4/#comment-297386
Firefox 3.0 is not releasing the memory used by tabs that are closed correctly. I shall be bugging this as soon as i have cleaned up my reproduction steps,.

Jake
That’s awesome! Thanks for doing the bug.

J23
I downloaded and installed a Windows XP update that fixes a GDI memory leak:
http://www.microsoft.com/downloads/details.aspx?FamilyID=9b5edfc8-a4bb-4080-9063-6518166e2dab&displayLang=en
and after that, FF3 memory has been very stable. I’ve been running this about 3 or 4 days now, and FF3 memory use is OK. So maybe that will fix the problem. I would like to hear feedback from others.
http://vba-m.ngemu.com Squall Leonhart
J23, stop pimping your antique Hotfix, IT DOES NOT APPLY TO SP3.
everyone else getting the issue, vote and validate @ https://bugzilla.mozilla.org/show_bug.cgi?id=464648
http://vba-m.ngemu.com Squall Leonhart
As for that Firefox optimizer, its a load of rubbish, it doesn’t make firefox use any less memory at all, it just dumps it all into the pagefile, which is NOT optimal for any application.
Starr
I have to agree with the sentiment of the article. I have installed Firefox 3.0.3 and its a dud. Runs slow, won’t scroll, eats up memory. I haven’t added in any plugs in etc, etc.
Jake
A new Firefox update came out today. Maybe it will be better.
v3.0.4
J23
Hey Squall,
All I know is that on SP2, I loaded that windows GDI leak fix, and my FF3 memory use stopped growing by 50K/second (by the end of the day, that was the rate before the GDI fix). Since my last post, I saw it spike one time up to > 1GB, but it’s not a daily thing like it was before. So I think this GDI fix helped my system to some degree at least. Thanks for posting the link to 464648. As for “pimping” — I ain’t got no purple velvet hat!