Fix Slow Firefox 3 on Vista with localhost
December 23rd, 2008
I’ve noticed that Firefox 3 is insanely slow loading web pages on localhost when using the ASP.NET Development Server (based on Cassini). Today something snapped in my head and I felt compelled to figure out what was wrong.
Everything was fine in IE7 and when connecting to the production web server from FF3. A few seconds plus a search engine revealed a simple solution:
- In in the Firefox address bar, type about:config and hit Enter.
- Click the "I’ll be careful, I promise!" button.
- In the Filter box, type network.dns.disableIPv6.
- Toggle the value of the network.dns.disableIPv6 setting to true.
That fixed the problem instantly for me. Hooray!
(photo courtesy of larry&flo)


December 23rd, 2008 at 8:42 pm
Thank you! I would have never guessed that in a million years.
I experienced the same problem and was wondering what to do.
January 30th, 2009 at 3:43 pm
Thanks man, saves me some loading time.
April 2nd, 2009 at 1:53 am
Thanks, I was getting ready to snap.
April 28th, 2009 at 5:12 pm
Thanks a lot man :) I took myself helpless and had to use IE each time when there was localhost requests. You are a great help :) Thanks again.
July 4th, 2009 at 10:34 am
hey man, u just saved me loads of nerves with my new laptop, thanks! it’s a pleasure working from home again.
August 14th, 2009 at 10:50 am
Is there any fix for the _web server_? I get this when using XML-RPC.NET as well. Unusably slow…
November 17th, 2009 at 6:17 pm
As we are on almost the same vein, can anyone tell me why when i first started to use Firefox with Vista it worked find but after a reload, Firefox 3.5.5 will not let me access or download a torrent from ANY torrent sites like isohunt, I get a popup window that says: firefox can not connect ,,,,, localhost:12322
Anyone have this one?
November 22nd, 2009 at 5:59 pm
Am I the only one in the world that cant get FF3.5.5 to download a torrent file from a fresh download of FF and a reload of vista?
IE7 does it just fine.
December 7th, 2009 at 10:42 am
Georgee,
most probably the problem is in the firefox extension “Torrent Server Handler” by Alon Swartz. Uninstall the extension and everything should work just fine.