The ‘How-To’ section has replaced the Firefox Extension Guru’s Wiki. In this section we list all the blog posts with directions on ‘How-To’ show/hide, enable/disable, add/remove and fix different things within Firefox. Please be aware that making these changes (especially if done incorrectly) can result in breaking Firefox. Please see the Disclaimer section for more information. Also note as newer versions of Firefox are released, some tweaks may stop working. If a tweak no longer works, please leave a comment on the post so that we can see if there is new information.

Below are some general usage instructions on how to edit your ‘user’ files, locate your Profile Folder and using Firefox’s built-in preference manager (about:config). If you wish to skip down to the ‘How-To’ section click here.

userChrome.css or userContent.css files

Some of the tweaks require modification to your userChrome.css and/or userContent.css files located in the chrome folder within your profile folder. Important warnings:

  • Changes made to the userChrome.css and/or userContent.css files can NOT be undone once saved. Therefore before making any changes to the userChrome.css file make a back-up copy first.
  • Firefox needs to be closed before saving changes made to your userChrome.css and/or userContent.css files. Firefox writes to these files upon exit and will override any changes you made if not closed first.
  • DO NOT REMOVE the line which starts with: @namespace in the userChrome.css file
  • This file should only be edited with a text-editor such as Notepad or Notepad++. It is NOT recommended using MS Word or similar Word Processor applications. For best results we recommend using the ChromeEdit Plus Extension. The extension will automatically locate your userChrome.css and userContent.css files and open them in an external editor. You will be able to modify these files, save your changes and restart Firefox.

Preferences Manager (about:config)

Some of the tweaks are done though the about:config interface where users preferences can be viewed and modified. To access the about:config settings Open a new tab and in the address bar type about:config then press enter. Note: If this is your first time accessing this interface you will get a humors warning. Click the I’ll be carefulbutton to proceed. More information on the about:config entries can be found on mozillaZine about:config entries.

Locating Your Profile Folder

From the Firefox Menu, select Help > Troubleshooting Information. In the Application Basics section click the Open Containing Folder button.