How to Fix Facebook Chat for Firefox Beta Versions and Daily Builds

I like to be on the cutting edge, but I don’t like the way if Facebook doesn’t recognise your useragent string it assumes you’re using an older non-compatible browser. This means you have to open chat in a new window, annoying at the best of times. So I did a little rummaging about and found a really easy fix for this.

  1. Go to your address bar and type in “about:config”. Click “I’ll be careful, I promise!”
  2. In the filter bar, type “general.useragent.extra.firefox”
  3. DoubleClick this to change the value. For me, it said “Shiretoko/3.5.7Pre”. I changed it t the nearest stable release I knew about, which was “Firefox/3.5.5”. For people using this guide in the future, you should go to and find the name of the latest release.
  4. Close about:config and load/reload Facebook
  5. That’s it, your Facebook chat should now be working fine!

I have not tested this on a lot of websites, but it should not cause any problems as long as the version numbers are quite close. Let me know how this goes for you!