I am having a little problem with Firefox on my Ubuntu, and I was wondering if someone could help me. The problem is that my Firefox started to act very slow after the v43.0 update. I am using Ubuntu 14.04 LTS 64bit.

Every page that I try to open takes about 5-25 seconds to load, and sometimes it doesn't load at all (displays that connection was restarted, or blank tab). I tought it was problem with my OS, so I started up Windows Vista in virtualbox with Firefox v42 (it wasn't updated yet), and went to compare it. And really the Firefox 42 on my Vista in Virtualbox was A LOT faster when opening pages (almost instantly) than Firefox 43.0 on my host OS - Ubuntu.

Then I updated the Firefox on Vista virtualbox from 42 to the version 43.0.2., and it was OK, the speed was the same. So no problems on the Virtualbox with the 43. But on host OS, my Ubuntu 14.04, Firefox 43.0 is very slow when loading any page. I read something about nvidia network manager on Firefox reddit, but I am not sure if I do have that program on my Ubuntu. I have laptop with optimus technology and I am using only Intel GPU, so Nvidia should not be the problem, right?

I also checked for updates, to see is there Firefox v43.0.2. for Linux also, but no new updates were found. I am huge fan of Firefox, but this is annoying, browsing the web is simply imoposible. It's even worse when you know that everything it's working fine on Virtualbox, but not on host OS. I tried opening my test pages on Ubuntu browser (based on Chromium) and it worked ok, the load speed was almost the same as on virtualbox. So that leads me to the conclusion - is it something wrong with Ubuntu or Firefox, and can it be fixed?

Note: The problem is that Firefox is slow to "contact" the site. It's like it is testing does website even exists, or does the connection works or something like that. After that, when the name of the site appers in the tab, it loads quickly web content. So the problem is in contacting the page, beacuse sometimes it showes nothing, just blank tab, or error message: "Connection was restarted".

I would really be greaful for any help. Thanks!

  • 1
    To make sure it's not due to an addon or a misconfiguration, start Firefox from a terminal with firefox -ProfileManager, create a new profile and start Firefox with this one and check whether it's still slow.
    – s3lph
    Dec 24, 2015 at 22:52
  • Hi, thanks for the fast reply. I do not belive that addon could be the problem since I didn't install any of my own. The only addons in use are the ones that came with the Firefox.
    – Kenan
    Dec 24, 2015 at 22:56
  • Please try nevertheless.
    – s3lph
    Dec 24, 2015 at 22:57
  • Ok I have tried it just now. I also powered on my virtualbox. Side by side test of Firefox show the same results. Updated Firefox on Windows Vista virtualbox is faster when loading any page (sometimes 2 sec faster, but sometimes even 15 sec faster). Firefox on Ubuntu, with new profile, is still slow.
    – Kenan
    Dec 24, 2015 at 23:12
  • 1
    Have you tried firefox in safe mode? Dec 25, 2015 at 9:51

1 Answer 1


The update with Firefox version 43.0.4 seems to solved the problem. Thanks everyone who helped :)

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