About:config

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Revision as of 17:32, 8 September 2005 by Alice (talk | contribs) (→‎Adding modifying and resetting preferences: replaced ''numbered'' with '''numerical''')
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about:config (one of the special About_protocol_links) lists application preferences read from "prefs.js", "user.js" and from program defaults, many of which are not present in the Options and Preferences dialog. You can use about:config to modify these preferences and to add other "hidden" preferences. Warning: Changing these values can, in rare circumstances, break Mozilla Suite, Firefox, or Thunderbird or cause strange behavior. Only modify these preferences if you know what you are doing.

Opening about:config

  • In Firefox and Mozilla Suite, type "about:config" (without quotes) in the Location Bar and press Enter.
  • In Thunderbird, use the AboutConfig extension. Starting with Thunderbird 1.5, about:config is accessible from the "Tools" menu (Options > Advanced > Config Editor button).
  • There's a version of AboutConfig extension compatible with Nvu here.

Adding modifying and resetting preferences

  • To add a new preference, context-click (right-click) anywhere in the list of preferences, select New then select the type of preference. String is a textual value, Boolean is true or false and Integer is a numerical value.
  • To modify an existing preference, context-click (right-click) on the preference, select Modify then type in the new value you wish to set.
  • To reset a preference to its default value or to remove an added preference, context-click (right-click) on the preference, select Reset.

about:config entries

This article contains a list of valid about:config entries and their possible values. (That article is a reference for what each preference does, it is not the place to edit your preferences.)

References