Firefox and Thunderbird Garage

IN THIS CHAPTER

• Locating Your Profile

• Using about:config

• Creating Profiles with the Profile Wizard

• Backing Up a Profile

• Restoring a Profile

• Using Multiple Profiles

• Importing Profile Information

• Sharing a Profile

• Profile Secrets for Power Users

Profiles are used by Firefox to store data that is specific to a user. You can save and restore profiles, share profiles with other users, and customize your profiles both by using Firefox and by carefully editing (perhaps using WordPad) the files that make up your profile.

When Firefox loads, it first loads all the default preferences. It then loads the preferences stored in prefs.js. Finally, it loads the preferences stored in user.js. Any setting in prefs.js overrides the default value, whereas any setting in user.js overrides both the default value and the setting in prefs.js (if one exists). Any change made using about:config updates prefs.js; if there is an entry for the preference in user.js, this change is ignored in favor of the user.js setting. Just remember the precedence order: Firefox defaults load first, prefs.js loads second, and user.js (if present) loads last.