Hi,

The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

Also, If you have security software (antivirus, firewall etc.) installed, you can try deleting all existing instances of Firefox and its related processes/files in all the different configuration modules/areas of the security software like process monitoring, sub/spawned process control, virtualization, HIPS etc., in addition to the security software's main configuration panel. Instead create new fully allowed/trusted rules for Firefox + its related processes in all the different modules/panels - a genuine/original Firefox installer as well as all the installed EXEs (Application) and DLLs (Application extension) are digitally signed by Mozilla Corporation (right-click > Properties > Digital Signatures). Even otherwise, some security software may also ask again when Firefox and/or its sub processes are started, and you may be able to allow/trust at that time. Please see this.

AV/Firewalls Configuration

For anyone using Firefox 17 who is seeing slowness, can you clarify what exactly is slow (Firefox startup, loading pages, using Firefox, etc.) also, if you'd be willing to work more closely with us to figure out this issue please let me know via pm.

Hi, after upgrading to Firefox 17 all browsing slowed down.

After doing several speed tests with Firefox 17 and IE9 I was getting 75% slower speeds with Firefox. After a lot of hassle I got back to v16.0.2 and my speed is back to normal.

A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/kb/Server+not+found
• https://support.mozilla.org/kb/Firewalls

All I can tell you is I disabled firewall/antivirus and ran in Firefox safe mode and it made no difference. Not going to put 17 on till it is sorted.

Have the same problem on linux. Without any firewalls/antiviruses

It looks like its fault of slow dns servers in my case

after updating to firefox 17 my computer became very very slow. The problem disappeared when I uninstalled something called sentoritray.exe that was in my startup programs. I think that this might have gotten installed when hp support assistant automatically updated itself. I remember it asking me whether I wanted to keep hp support assistant in the system tray. It seemed strange at the time because its never asked me that before.

So it looks like people are still seeing some slowness issues? Any information you can provide would help us to diagnose the issue if one does exist. As Tyler mentioned, simply saying that it is slow is pretty vague. We need more detailed information about what exactly is slow and we may need some volunteers to do some 1 on 1 investigations.

So if you are having issues with the speed of FF 17.0.1, please let us know!

I have a similar problem since I upgraded to 17.0.1 If I don't use Firefox for some time (10-30 min) and I load a new page I get fast. However, if I load another page or link a few seconds later Firefax needs 15 or 20 s until the page is loaded. During this period I hear disk activity and see CPU load caused by FF.

Can I first apologize, it seems the problem was with F-Secure TalkTalk security that was causing the problem. I found this and it seems to have done the trick.

Which security software (firewall, anti-virus) do you have?

If you use F-Secure Browser Protection then see:

   http://community.f-secure.com/t5/Protection-Safe/Browser-Protection-is-making/td-p/2355/page/6 

Try to disable "Use advanced process monitoring" in the F-Secure Deepguard settings.

   open Computer Security main window and select "Settings"
   in settings dialog go to "DeepGuard"
   uncheck "Use advanced process monitoring" checkbox

Hi, I have tried the Reset Firefox, I have switched off the Firewall, I have even upgraded to Firefox 18 Beta but nothing helps. I have so much slowness with Firefox since upgrading to 17 it is frustrating.

I have tried the following: opening Firefox leaving all other programs closed. Opening Windows Taskmanager (by the way I have a very fast Sony VAIO with Windows 7) next to it. Enter "chocolate chip cookie recipe" in the Google search bar and pressing enter (start stopwatch). It takes a full minute before the Google results come in view. Processor usage does not go above 40% and memory usage doesn't increase much. But then my computer becomes so slow my mouse cannot click on any links shown in the page. Or on any other menu or program for that matter. It takes another 40 seconds for my computer and Firefox to respond to a mouseclick. I click on the first link. Now Firefox really gets stuck. 1minute and 42 seconds later the resulting website pops up. Processor usage was at its highest 48% and memory still the same. So it takes Firefox 17 over 3 minutes to render search results and open the first link of the search results. I have tried this with several other simple searches. I am not sure what to do now as I use Firefox mainly for my work... I hope the slowness is detected and solved soon. Firefox 18 (beta) was no solution to me... Isolde

I found the cause for Firefox 17 slowing down to be different. This maybe helpful to someone. On loading my CMS, I found Firefox ground to a halt. I started up Firebug and accessed the NET tab and reloaded. I found that if it was trying to load a resource that wasn't there - in this instance an image from a Jquery library - Firefox wouldn't ignore it, it would just 'hang' there and tried to load, instead of ignoring it. On removing the call to the image, the site loaded fine. I retested this by adding a call to an imaginary CSS file and this proved the same. Rather than ignore it like I would expect it to, it just waited to try and find it. If you have the same issue, try loading the site with Firebug and see if that is the issue.

Hi rl435,

unfortunately, I'm not familar with the usage of HTML or Firebug. I solved the problem by downgrading to FF 16. FF 18 beta had the same problem for me.

If it's helpful, I will upgrade again and check the issue. However, I need a more detailed described for what I shall look where.

BR

  Jan

I'm sorry to jump into this thread but I am trying to find a solution for the slow fetch in Firefox when I use two websites. These are when I log onto ebay and also into natwest online banking. Tesco (also a https site) doesn't have a slow fetch and nor does Amazon. The fetch is instant in Chrome with the problem sites, so this must be a problem with FF. Natwest is the worst - it can sometimes take around 30 seconds to do anything and during that time I can't move between tabs - the whole browser is frozen. I've cleared history/cache, etc. Starting in safe mode with add-ons disabled doesn't do anything. I've just updated Java but no joy. Can anybody help?

Sorry, just to clarify, it is when I have put in my log in details and I hit submit.

I had the same problem, after upgrading to firefox 17 at first everything was as always. But after a few days pages which usually loaded in like 2 or 3 seconds started to take 20 to 30 seconds to load . I tried disabling a few add-ons to see if anything would shange firefox behavior, then i tried restarting with all add-ons disabled, but nothing changed. So yesterday I just decided to resort to something I never tried to, and I just used the reset firefox option. I configured firefox to look like it was before the reset and so far it is like new and firefox no longer takes forever to load the pages. So if nothing else works for you maybe try the reset option, but be aware that you will loose all your personal configurations and and you will have to intall all your add-ons again but for me it was worth it as firefox is now working as it used to. So here are my 2 cents, I hope it will be usefull to people in similar situations to mine.

I have experienced the same thing with webpages slow to load. Have not tried the reset option yet. But I can explain why the pages are loading slowly.

I went to speedtest using the same server for consistent tests. I installed Chrome as an alternate browser to test both side by side. Facebook being one of the most resource intensive websites is a great example. Remarkable difference between the browsers. When testing them side by side a year ago or so could not see a difference.

The speed test for upload and download speeds came back about the same. 32 mbs upload and 4.5 mbs download. But the ping test was 10x slower with Firefox version 17. Maybe even noticed it with a few versions back. Chrome was 10ms. Firefox was 104-120ms.

I'm going to try the reset and run the comparison tests again.

I did the reset. Here are the speedtest results. Download speed 32mbs. Upload speed 5mbs. The ping test went from 104ms to 57ms. Chrome still at 10ms. So there is still something wrong with Firefox. Nothing has changed on my machine or any of the other three which are experiencing the same problem.