There are many hidden preferences in Firefox which may be configured. This can be done by modifying about:config.
What is about:config?
about:config is a special page that lists all Firefox preferences, many of which are not present in the Tools/Options dialog. Preferences can be changed here.
How do I view about:config?
In Firefox, you type “about:config” in the Location Bar. You will be given a humors warning about voiding your warranty. This is Mozilla’s way of saying that you need to be careful. Click the I’ll be careful, I promise button to access the editor. A long list of Firefox preferences will be displayed.
What do all those preferences mean?
The list of preferences is not always well documented. Here are sites that include definitions of the most widely used preferences:
- http://preferential.mozdev.org/preferences.html
- http://kb.mozillazine.org/index.phtml?title=About:config_Entries
How do I change the preferences?
Warning: Changing these values can, in rare circumstances, break Firefox or cause strange behavior. Only edit these preferences if you know what you are doing.
A step-by-step tutorial with screen shots for editing about:config is here:
What else can I do?
We have a large collection of step-by-step tweaks here on the Wiki.
