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July 29, 2008

Customize Firefox’s Default Profile Without Creating One

We recently ran into problems with our default Firefox profile after upgrading to Firefox 3. Before, we’d defined a default profile in the default user’s ~/Library/Application Support/Firefox/Profiles folder, set it up to have the settings and homepage we desired, and let that copy into a new user’s profile on login. After having some problems with some of the settings that restricted extension installation, we discovered a way to define defaults for Firefox without having to pre-create a user’s profile. There are a few files to change in the application bundle that cause it to work as we’d like:

Your needs may vary, and you can do a lot more inside the application bundle, such as putting extensions in the /Applications/Firefox.app/Contents/MacOS/extensions folder. Putting default settings here has two main advantages over putting it in the default user profile:

  1. Firefox profiles are only created as needed. Not copying over a default profile reduces login time, and users who use Safari will never need a Firefox profile.
  2. Using a default profile, all profiles have the same name (e.g. ~/Library/Application Support/Firefox/Profiles/m6oj7kr0.default/). The method I’ve outlined in this post results in differently-named Firefox profiles. I have no idea if this is an advantage, but Firefox’s developers randomize the profile folder name for a reason, and this method preserves their methodology.

Update 8/5/08: Added application.ini info.

Posted by slauncha at July 29, 2008 03:03 PM

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I have not been able to get Firefox 3.0.2 to honor any changes I make (per this article) to prefs.js.
HOWEVER, with some hacking around I have come up with an alternative that I hope helps other users:

Instead of editing prefs.js, try editing firefox.js. This resides not in ...defaults/profile but ...defaults/pref. Add your settings there in the format pref("xxx") in lieu of user_pref.
Now all our newly formed user profiles have the proxy, startup homepage, and other defaults that want/need them to have. Happy hacking!

Posted by: kurt.tappe@chase.com at November 6, 2008 09:06 PM

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