Try disabling graphics hardware acceleration. Since this feature was added to Firefox, it has gradually improved, but there still are a few glitches.

You might need to restart Firefox in order for this to take effect, so save all work first (e.g., mail you are composing, online documents you're editing, etc.).

Then perform these steps:

• Click the orange Firefox button at the top left, then select the "Options" button, or, if there is no Firefox button at the top, go to Tools > Options.
• In the Firefox options window click the Advanced tab, then select "General".
• In the settings list, you should find the Use hardware acceleration when available checkbox. Uncheck this checkbox.
• Now, restart Firefox and see if the problems persist.

Additionally, please check for updates for your graphics driver by following the steps mentioned in the following Knowledge base articles:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

• Upgrade your graphics drivers to use hardware acceleration and WebGL

Did this fix your problems? Please report back soon.

Thank you for taking the trouble to answer. Unfortunately, even after following your advice (and the advice of quite a few people before you !) there is no improvement. To recapitulate :

I’ve trashed Firefox and reinstalled it many times, and tried several new versions over the years, with no success. And now, in the last few days, using FF 25, I have done the following :

- troubleshooting extensions (add-ons): Following advice from the Add-ons manager, updated two. They’re now all up to date. Restarted Firefox, still freezes.

- restarted Firefox in safe mode. Still freezes

- unchecked “use hardware acceleration when available” and restarted. Still freezes

- created a new profile and restarted. Still freezes

Can you tell me why these fixes (or attempted fixes) are necessary ? Firefox is the only browser ( and there are many) that doesn’t work straight away after installing. Why ?

As for my graphics drivers, they're all up to date. I have always installed these updates from Apple, and in this case the entire operating system is new !

Have you tried starting your Mac in safe mode.
View more here.

Thanks for taking the trouble to suggest a possible solution. No, I haven't tried restarting my Mac in safe mode. I don't need to do that (or any other fix) with other browsers. Why should I have to do so in Firefox ?

I'm now disgusted, and I'm thinking of giving up on FIrefox altogether.

I wish Mozilla would acknowledge that there is, quite simply, something wrong with it.

We are sorry that you are displeased with our service here at Mozilla.
Putting your computer into safe mode is not a solution, rather a way to test that there is not another program interfering with Firefox.
We will do all that we can do to try to solve your problem.

Can you please see if Firefox freezes in your computer, when in safe mode?
Thanks in advance and sorry for any inconvenience that this issue has caused.

Dear ComputerWhiz

Thank you for your email. And I’m not really displeased with your service as such - merely with Firefox, which doesn’t work on my iMac. Other users have contacted me to say they have the same problem.

I use Safari and Chrome, and occasionally use SeaMonkey ( mostly for its html editor). I also have Opera and Maxthon which I don’t use often, but they’re part of my “collection”. All of them work well. All except Firefox.

Starting my entire computer up in safe mode was an interesting suggestion, one I hadn’t tried. I’ve now done so, and although Firefox seems to have worked without a hitch in your help pages and forums, it froze immediately when I went to a magazine website. I force-quit and relaunched, and went to the BBC’s website. As soon as the website opened, FF froze.

It was worth trying, though, like all the other ‘solutions” I’ve tried before. And I’d really like to know what’s wrong.

However, if the answer is found but it means resorting to a “fix”, this will hardly be satisfactory. Why should a “fix” be necessary, if it isn’t with other browsers ? Would the Firefox front page carry the warning “Different by design: the browser that needs adjustments before working properly” ?

However, thank you again for your email and offering to help.

PS: once or twice when trying out Firefox I left it alone when it froze. After about two or three minutes I got a message warning of an "unresponsive script". A button (highlighted) offered the option to stop the script, but this was useless since FF was frozen and no amount of clicking, on the button or on anything else, made any difference - so I force-quit FF as usual.

What script did Firefox claim was unresponsive?

I know that you have said above that you have uninstalled Firefox.
I need to ensure that you have performed a clean reinstall.

This means you remove Firefox program files and then reinstall Firefox. Please follow these steps:

Note: You might want to print these steps or view them in another browser.

1. Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
2. After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
3. Delete the Firefox installation folder, which is located in one of these locations, by default:
   • Windows:
     • C:\Program Files\Mozilla Firefox
     • C:\Program Files (x86)\Mozilla Firefox
   • Mac: Delete Firefox from the Applications folder.
   • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
4. Now, go ahead and reinstall Firefox:
   1. Double-click the downloaded installation file and go through the steps of the installation wizard.
   2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

Please report back soon.
I apologize if you have already tried these steps. Please ensure that these are the exact steps that you have followed because using the Firefox uninstaller with the Firefox package will not solve most issues.

Every time I have tried a new version of Firefox and trashed it I have been careful to trash the associated files too (using an application called Appclean) and performed a clean reinstall. I've been doing this for several years.

As I said in my first post (see above) I am indeed using the latest version of Firefox ( 25 ) which I have trashed and ( clean ) reinstalled twice.

Re- your question concerning the unresponsive script. Last time it happened, as far as I can remember no script in particular was mentioned in the notification.

This evening I launched Firefox and went straight to the Mozilla pages to see if they would open all right. I reached the Mozilla Support page entitled "Get started with Firefox - An overview of the main features". Then Firefox froze. Yes : it actually froze in a Mozilla support page. So if a script is at fault, this time it's a script in that page. The frozen page has been there for five minutes now, with no notification message. I'm disgusted and force-quitting Firefox. BTW I'm sending this using Chrome, which has worked ever since I first started using it.

Just now, as I was going to force-quit, the frozen page unfroze - so perhaps it was only "hanging" - but it did this for 5 minutes, during which time it didn't respond to any command.

After it unfroze I decided to conduct a small experiment : I went back to the previously visited Mozilla page, with no trouble, then forward again to the page where Firefox had frozen, to see if the problem was indeed with that page. Sure enough, it froze again. So if there is an unresponsive script, it's contained in that page.

The same systematic hangs/freezes occur with all the other websites I try to visit .

I wish you could understand how baffled I am. What I think about Firefox can be imagined : the only browser that freezes in this way, and even freezes in its own help pages.

BTW you mention "using the Firefox uninstaller with the Firefox package". There is no such uninstaller.

As I said, I use Appclean

Note that mac doesnt have a Firefox uninstaller, you just trash it.

Can you try Firefox in a new profile.

• Profile Manager - Create, remove or switch Firefox profiles

Hi Waka Flocka Flame

I did that several days ago (see my post dated November 2nd ). No joy.

The method suggested asks me to use Terminal. But the command I'm told to put in results in " No such file or directory".

Besides, I've trashed Firefox and its associated files twice since I tried changing my profile: surely I got a new profile every time I did a clean reinstall ?

How about troubleshooting info...

Please do the following:

• Click the Firefox button at the top left, then click the Help menu and select Troubleshooting Information from the submenu. If you don't have a Firefox button, click the Help menu at the top and select Troubleshooting Information from the menu.

Now, a new tab containing your troubleshooting information should open.

• At the top of the page, you should see a button that says "Copy text to clipboard". Click it.
• Now, go back to your forum post and click inside the reply box. Press Ctrl+V to paste all the information you copied into the forum post.

If you need further information about the Troubleshooting information page, please read the article Use the Troubleshooting Information page to help fix Firefox issues.

Thanks in advance for your help!

Hi Waka Flocka Flame. I've followed your suggestion, and here is what I found in about:support.

Application Basics Name Firefox Version 25.0 Update History Show Update History User Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:25.0) Gecko/20100101 Firefox/25.0 Profile Folder Show in Finder Enabled Plugins about:plugins Build Configuration about:buildconfig Crash Reports about:crashes Memory Use about:memory Extensions Name Version Enabled ID

Important Modified Preferences Name Value browser.cache.disk.capacity 358400 browser.cache.disk.smart_size_cached_value 358400 browser.cache.disk.smart_size.first_run false browser.cache.disk.smart_size.use_old_max false browser.places.smartBookmarksVersion 4 browser.sessionstore.upgradeBackup.latestBuildID 20131025151332 browser.startup.homepage_override.buildID 20131025151332 browser.startup.homepage_override.mstone 25.0 extensions.lastAppVersion 25.0 font.language.group x-western network.cookie.cookieBehavior 2 network.cookie.prefsMigrated true places.history.expiration.transient_current_max_pages 100664 plugin.disable_full_page_plugin_for_types application/pdf plugin.importedState true privacy.sanitize.migrateFx3Prefs true Graphics Device ID 0x 869 GPU Accelerated Windows 1/1 OpenGL (OMTC) Vendor ID 0x10de WebGL Renderer NVIDIA Corporation -- NVIDIA GeForce 9400 OpenGL Engine windowLayerManagerRemote true AzureCanvasBackend quartz AzureContentBackend quartz AzureFallbackCanvasBackend none AzureSkiaAccelerated 0

JavaScript Incremental GC true Accessibility Activated false Prevent Accessibility 0 Library Versions

Expected minimum version Version in use NSPR 4.10.1 4.10.1 NSS 3.15.2 Basic ECC 3.15.2 Basic ECC NSSSMIME 3.15.2 Basic ECC 3.15.2 Basic ECC NSSSSL 3.15.2 Basic ECC 3.15.2 Basic ECC NSSUTIL 3.15.2 3.15.2

The only thing I think I know is that:

- Firefox hangs/freezes for several minutes in practically every web page I visit (although not Google).

- I once got a notification telling me about an "unresponsive script" but could do nothing about it (FIrefox being frozen)

- if a script is indeed to blame, it's to be found even in Mozilla's own support pages

- Firefox worked up to version 3.5 ( in 2009). The problem has been there in every subsequent version.

- This, and the fact that Firefox is the only browser to have that problem, leads me to believe that it has a bug, a weakness of some sort.

- I have been contacted from time to time by other users who experienced exactly the same difficulty.

This is, first, to thank those of you who are trying to help.

Second : I have already said repeatedly that Firefox is the ONLY browser that causes these problems. Others work, so there doesn't seem to be anything wrong with them. Or with my iMac.

If the fault is not found in other browsers, and if my computer handles these with no difficulty then -logically- the only problem is with Firefox itself. Perhaps a feature of FF that others (fortunately) don't have.

What makes Firefox unique in this way ? Trying fixes and workarounds is a first step, but it shouldn't be necessary. Unless, of course, it helps to identify the weakness in Firefox.

I could give up completely and forget FF. But it's one of the main browsers 'out there', with a good reputation, and this baffles me. I'd really like to know what's wrong with it.

A moderator (AliceWyman, whom I thank for her post) suggests I reset Firefox. I've done that, more than once.

The problem remains. And so does my question : why does Firefox keep on hanging/freezing ?

Why should fixes be necessary? Mozilla, in its Firefox page, generously offers the browser free, and users assume that it will, simply, work. In my case, it doesn't.

And as I've said: I've tried a whole range of fixes and workarounds (that aren't necessary with other browsers) and they haven't worked. If my iMac can handle all the other browsers with no problem, this indicates that the computer works, and that the other browsers do too. So this problem seems to be a specific Firefox one.

As I've already said, I could just give up and use Safari, Chrome, Chromium, SeaMonkey, Maxthon, or Slimboat, for instance.

But it irks me that FF, with such a good reputation (it's the third most widely used browser), should behave in this way.

"Different by design", says its webpage. Well, it's certainly different. Can anyone help? I've been asking these questions, trying "fixes", trashing and clean-reinstalling for about a week now.