What to Do When Firefox Stalls or Hangs

To sustain this free service, we receive affiliate commissions via some of our links. This doesn’t affect rankings. Our review process.

I have encountered this problem off and on. Below a list of possible reasons for Firefox hangs:

Potential Sources for Firefox Hanging

  • HyperThreading
  • User Agent Switcher
  • JavaScript
  • MS Anti-Spyware
  • McAfee Antivirus
  • Adobe TypeManager/ Font
  • Extensions
    • Changes regularly as extensions are updated – post the extension you are having problems with below.

Some Solutions

The reasons for this problem vary but here are some troubleshooting tips to try when Firefox stalls or hangs to get you back up and running. My solution for the moment is to clear the cache, and reduce the memory load. I also had a problem with the Tabbrowser Extension (known also to conflict with FCKEditor and TinyMCE, among other things), which I replaced with TabMix Plus, and that seemed to solve the problem. Another extension that I think is great but unfortunately is experiencing extreme memory leaks is TagAlert. Hopefully a future release will solve the memory leak issues.

If All Else Fails

If all else fails reinstalling Firefox, disabling all extensions, and doing the following will almost always solve any issue:

Windows: Rename the “Firefox” folder in the following directory: C:\Documents and Settings\USERNAME\Application Data\Mozilla to something like “Firefox-bak” and reload Firefox. Post any questions below.

About The Author:

Alex has been involved on the business side of the internet since the early 2000's. He holds both a Management Science degree from the University of California at San Diego as well as a Computer Science degree from NJIT.

We Rock Your Web had its roots back in 2004 as the tech blog for a web design and development company Alex founded that has grown and evolved into the parent company of We Rock Your Web.

While his foundation is rooted in web development, his expertise today lies in content and digital marketing, SEO, organic and paid search, analytics, and publishing. Alex is an avid tennis player, nature enthusiast, and hiker, and enjoys spending time with his wife, friends, and dogs.

Disclaimer: This website contains reviews, opinions and information regarding products and services manufactured or provided by third parties. We are not responsible in any way for such products and services, and nothing contained here should be construed as a guarantee of the functionality, utility, safety or reliability of any product or services reviewed or discussed. Please follow the directions provided by the manufacturer or service provider when using any product or service reviewed or discussed on this website.

Leave a Reply

newest oldest most voted
I was continuously facing this issue as my firefox freezing up. Then I cleared all my Browser history of my mozilla firefox. After Doing this my firefox is running smoothly and freezing issue was also solved.
Martin Alcock, M. Sc
I agree. I have been a firefox user for many years as well, but when it starts hanging and has to be restarted all the time one not one but three machines, there is an obvious problem with it, and no apparent fix other than diddling around with it. I switched to Chrome instead and all my problems went away.
Interesting suggestions – I was fascinated by the insight – Does anyone know where I might be able to get ahold of a blank form copy to edit?
I’d been pulling my hair out for days then COMPLETELY CLEARED MY HISTORY and voila suddenly my Firefox did not freeze anymore. I’m continuing to type only cause I can and IT’S NOT FREEZING ANYMORE!!!


I hope this works for everyone. I know firsthand how completely frustrating having to restart every couple of seconds can be.

Kimberly Alt
Yay! So glad it worked for you Christon! Thank you for reading and commenting with your success.


a web rocker
My Firefox 15.0 hangs briefly while (or after) loading image sites such as Pixiv or Deviantart. It seems no extension or configuration seems to help with this. Can you tell me why this happens and how to fix it? There seems to be no topic at all about it on the web.

P.S.: It is ESPECIALLY bad with Pixiv. Like, really bad right now.

Firefox is crap since version 3.5. It has become too large to be useful. They need a full rewrite.

In the mean time, just use Chrome, which is still lean and mean.

a web rocker
Aside from Google’s surreptitious data-mining activities these days (keep your corporate snout outta my web searches and people’s WiFi, Google!), they’ve created a monster by running a separate process for every tab in Chrome. If I open 20, 30, 40, or more tabs (which is normal for me in my online activities), that eats up so much RAM that it affects the proper operation of the machine. (I have 4GB of Crucial DDR2/PC2-8500 in my Athlon 64 X2 Black Ed. 5000+ box.)

Also, Chrome is really lacking in the extensions department. Their Session Manager lacks a proper dialog prompt when shutting down, BugMeNot doesn’t work at all, its NoScript is inferior to Firefox’s, they lack a good .FLV video downloader, etc…. (If I’m wrong about any of the extensions I mentioned, I stand corrected.) Still, Chrome ain’t the greatest: overall, Firefox still kicks its arse. Yeah, Ff needs work, but, saying it’s crap since v3.5 is BS.

I now need to go to task manager to close Firefox. I’ve been a user for years but I have just finished getting all my passwords into Internet Explorer (took two days). I am dumping this sh#t browser for Microsoft (I still do not believe it!). Sorry Firefox, but I’ll try you out again in a few years.

Hey, I was trying to fix my hanging, non-opening and delayed actions problem when I noticed your comment on the pain of reinstalling passwords.

I am a web designer and deal not only with my passwords but also my clients and their accounts when I need to create affiliate websites for them.

I used to use the browsers system, then a separate lock box on my computer but that errored out on me once and I lost all that. Now I use a free online service called last pass (lastpass.com). Its been great for the last year and a half. I highly recommend it.

I don’t even try to remember passwords any more, I let it generate secure passwords and remember. Most of my clients are return customers so it saves a lot of time dealing with so many accounts.

I don’t get any commission for telling you this, I am just passing it on because it’s a great service I think you’ll appreciate as much as I do. It works with chrome FF and IE which is great because I test in all these browsers.


Been having problems for a couple of weeks, and did the following this evening. Not only is FF ok now, but my laptop is like lightning. It will take a little time, but it works a treat.

* Download Revo Uninstaller Pro (You get a 30 day free trial)
* It’s very idiot proof to use. use it to uninstall:-

* Java
* Flash (And all plugins)
* Aany current versions of Firefox

* Shut down (NOT RE-START) – Shut down your computer and start it up again
* Use the following features of Revo Uninstaller:-

* Windows Cleaner
* Microsoft Office Cleaner
* Browsers Cleaner
* Junk Files Cleaner
* Autorun Manager (Take away things like Yahoo messenger, MSN Messenger etc, you can start them up by yourself, it’s not hard)

* Once all that is done, SHUT DOWN your PC once again, and re-start again.
* Re-install:-

* Java
* Flash
* -Firefox

* Final tie, SHUT DOWN your PC and re-start.
* You will now notice that your PC is tunning a lot more crisp and fast.
* Open Firefox. The first time you go to a website that needs Flash, a bar at the top will pop up, tell you need a plugin. Install it.
* Go to Youtube, and enjoy your viewing:)

Thank you for this…omg so works.
Hard to download revo when Firefox simply refuses to work 😉 My Firefox is pretty much unusable now due to hanging.
Although I wanted to avoid it since I’ve been with Firefox for many years I just switched to Chrome, and everything works properly.

Every time I browse Facebook, Firefox hangs for sure, I guess its because of JavaScript, cos Facebook runs the chat app. n stuff using Java. I have not yet found a solution for this. I don’t know if any extension is causing this. I will try disabling a few extensions and update if its solved. Any help would be appreciated.


For some of the non-tech I have just started using IE. Crap now I get with all the MS crap.

So here is a call for help. FIREFOX FIX IT. Just give me a new update and do what is needed. I don’t have time for this and am getting pissed off restarting all the time. This brings be back to the good old blue screen of MS and a reboot to solve it.

Firefox, please don’t get too big to care and start developing garage.

firebug was causing many hangs for me. smartzip maps would not load until I disabled firebug or explicitly forced a refresh (CTRL-F5). disabling firebug not only made the hangs go away but my browsing experience was so much faster. I guess there is always a performance trade-off when running in some sort of “debug” mode.
Thanks for the tip. I only use firebug on occasion, but after reading your post it did seem that the timing of my stalling problems might coincide with installing firebug. It looks like I’m good now!

Yup – I also had the history file problem. Thanks for the tips and the article, glad to have this working again.

Possibly unrelated, but Yahoo’s finance site keeps freezing up in Firefox. Any idea why this would be happening?

I had the same hanging problem with constant disk access whenever I try to load Firefox.

I got rid of places.sqlite and places.sqlite-journal and it worked again.

Getting rid of places.sqlite and places.sqlite-journal works too.

Thanks for the tip.

Thanks, this one has been wasting SOOO much of my time. This should be a bug.
Hmm, nice stuff, I also was suffering from this trouble that Firefox used to hang over the period of time, I got the problem because the antivirus software would loose up the system and it results in the hanging the system, but when I found antispyware software the problem vanished very fast and I am happy.

Ok.. so I just formatted, reinstalled windows… first thing I install is Firefox 3… Hangs immediately. So I try the compatibility mode change… now Firefox won’t open. I have nothing in my extensions menu either. Any ideas? I’m lost now.
check about:config for “network” and reset all entries you see had changed (in bold).
In most cases, it’s not extensions. If your history cache is too big, that is the cause. Delete old links from history and reduce the number of days of history to save and the problem will be fixed.
Reducing the history solved the problem I had with my Firefox freezing for short periods of time. Tools -> Options -> Privacy. I then reduced the “Keep my history for at least” from 90 days to 7 days and clicked the “Clear Now” button to clear old history.
This also worked for me, although I suspect it was the “Clear Now” more than reducing the history.

I selected the cache and cookies as well as browsing and search history with the Clear Now option.

For me, it was Google browser sync that caused a stall with a period of ~50 seconds. These were my debug steps: 0) Download Process Explorer from the MSFT site. 1) Start up firefox, but don’t do anything with it. 2) Start Process Explorer and look at the CPU usage graph for firefox. 3) If you have my problem, you will see periodic spikes in CPU usage, even though nothing is happening. 4) Go to Tools->Add-ons and disable one of the extensions. 5) Restart firefox and observe CPU graph (it will be a new PID in Process Explorer, so you’ll have to launch a new graph as well). 6) Repeat steps 2-5, changing only the extension that is disabled until you no longer see the spikes in the firefox process CPU graph.
Alex Schenker
Excellent stuff! Thanks so much for the tip!