Raymond.CC Blog

Most of the advanced computer user that uses Mozilla Firefox should know about the hidden about:config link. By typing about:config in the url area, a warning window will appear telling you that this might void your warranty and changing these advanced settings can be harmful to the stability, security and performance of this application. After clicking the I’ll be careful, I promise button, a page with probably hundreds of hidden settings will appear.

The settings found in about:config is not something you can simply enable or disable because if you do it wrongly, chances are websites will load slower than usual, takes more memory usage, or even crashing your computer. Of course there are some settings which is deemed as safe for you to configure but unfortunately it’s not easy to tell which one is safe or not since there are hundreds of settings in there. For our convenience, Thomas Leberbauer has written a useful Firefox addon that allows us to safely configure the hidden options in about:config.


gui:config is an extension for the browser Mozilla Firefox and provides many additional useful options. It makes it easier to change preferences that can only be found in the about:config. The extension supports a comfortable way to apply changes to these options. It displays the options, included in the current version, using checkboxes, dropdownlists and textboxes.

After installing gui:config addon, just click the Tools from menu bar and select Advanced Settings to access the graphical user interface of about:config.

gui:config does not have every single options found in about:config. It only provides options that are safe for basic computer users to play around. It even has description of every option that is listed in gui:config so you could understand the options that you see there. If you’re experiencing problems after blindly configuring about:config via gui:config addon, you can revert the changes back to default by clicking the Reset All button. You can even reset one specific option to its default value just right-click on it and choose “Set to default value”. The change takes effect immediately without restarting Firefox.

[ Install gui:config addon for Firefox ]