Question: Firefox 3 is very slow on my Ubuntu. How do I fix it? Some of the symptoms are — Scrolling on a web page is very sluggish, running flash on Firefox is slow, watching YouTube videos on Firefox is slow.
Answer: Try one of the following suggestions, which may solve the Firefox running slow problem on Ubuntu.
1. Set Ubuntu Appearance Preference to None
Go to System Menu -> Preferences -> Appearance, this will display the ‘Appearance Preferences’ dialogue -> Click on Visual Effects Tab -> Change the value from ‘Normal’ to ‘None’ as shown below. Restart the Firefox browser, which should solve the performance issue.
Fig: Ubuntu - Set Appearance Preferences to None
Note: This is an issue only on the laptops and desktops that doesn’t have a good video card. On most new laptops and desktops, you may not experience Firefox browser slowness because the Appearance Preferences was set to ‘Normal’
2. Disable the IPv6 at the Firefox browser level
From the Firefox address bar, where you typically type the http:// URL, type about:config, which will display the following warning message. Click on ‘I’ll be careful, I promise!’ button.
Fig: Firefox browser about:config warning message
In the Filter box, type “ipv6″, this will display a single line with the following columns:
- Preference Name: network.dns.disableIPv6
- Status: Default
- Type: boolean
- Value: false
Select this line and right-click anywhere in the selected line, which will display the following menu with a menu-item called Toggle. Click on the Toggle, which will change the Value from false to true, which will disable the IPv6 only on Firefox browser.
Fig: Set network.dns.disableIPv6 to true in Firefox
After the toggle, following are the column values. Restart the Firefox browser which should solve the performance issue.
- Preference Name: network.dns.disableIPv6
- Status: user set
- Type: boolean
- Value: true
Get free Unix tutorials, tips and tricks straight to your email in-box.
If you enjoyed this article, you might also like..
My name is Ramesh Natarajan. I will be posting instruction guides, how-to, troubleshooting tips and tricks on Linux, database, hardware, security and web. My focus is to write articles that will either teach you or help you resolve a problem. Read more about 
{ 6 comments… read them below or add one }
Also try disabling backgound images using a GreaseMonkey script.
For me it works the next firefox addon: Yet Another Smooth Scrolling 2.0.21. Is very customizable. Thanks so much for your blog, interesting articles and your mailing.
(off-topic) I hope not to boder you, but if I could ask for a tread, I would like you write about How-to multi-boot Ubuntu, Puppy Linux and another distro as Slakware properly. I don’t want to risk my configuration and I read something about that on Ubuntu forums but is not enough clear for me.
Thank’s
I have had my Firefox browser with the settings you described, for quite some time now. Yet Firefox is still as kludgy as ever. Any other suggestions, other than switching to another browser?
@Binny,
Thanks for sharing your script. On most cases (especially when someone noticed the scrolling issue on ALL websites), I’ve seen it is mainly because they got an old video card on their system. In those cases, setting the Ubuntu appearance preference to “None” might solved the issue.
But again, there are always several reasons why scrolling on firefox could be slow. Thanks for sharing your issue and solution.
@Alfons,
Thanks for bringing “Yet Another Smooth Scrolling” firefox add-on to our attention. It looks very interested. I’ll check it out.
PS: I’ve taken note on your off-topic and added it to my list of things to do for future posts.
@Zeke,
You may want to try the suggestions given by Binny and Alfons above and see whether any one of it fixes your issue.
Ramesh Natarajan posted:
{{ You may want to try the suggestions given by Binny and Alfons above and see whether any one of it fixes your issue. }}
Binny recommends “disabling backgound images using a GreaseMonkey script.” But upon reading the reviews, it seems that Greasemonkey does not work for Firefox 3.5. See:
https://addons.mozilla.org/en-US/firefox/reviews/display/748
(Search for “3.5″ to find those comments.)
And Alfons recommends “addon: Yet Another Smooth Scrolling 2.0.21″. Well, I have my doubts, since I’ve tried all methods to speed up Firefox ever since they had such suggestions…and none of them have ever worked for me. Here are some negative reviews that I find discouraging:
“It’s great and all with nice and smooth scrolling but it uses WAY too much CPU. On some pages it makes my computer go to 70% and sometimes even 100% CPU Usage! I also noticed on YouTube it makes the video drag.”
The above quotes all come from this URL:
https://addons.mozilla.org/en-US/firefox/reviews/display/5846
I think I’ll just keep my fingers crossed, that the next Firefox update will resolve the slowness glitch. After all, browsing speed is one feature the Firefox creators pride themselves on…so I don’t think they’ll neglect this issue for long.
But thanks just the same for your suggestions, Ramesh.
A better solution would be disabling smooth scrolling in the options. Disabling IPv6 support is a weird idea.