Firefox provides command URLs so that a user or developer can see some internal information about the browser. They serve as a diagnostic and troubleshooting tools when developing websites, especially when developing for advanced features of browsers like IndexedDB, Service Workers, etc.
URL Format
These pages can be accessed by typing the corresponding URLs in the Address Bar. The URL format is ‘about:’ following by the page name. An example is given below:
about:preferences
Type this into the address bar of the Firefox browser and it should show the Preferences page.
Complete list of Firefox about: pages
Below is the complete list of all available Firefox about: pages:
| URL | Description |
|---|---|
| about:about | List of all about pages available |
| about:addons | Displays information about the addons |
| about:buildconfig | Displays information about the build configuration used to compile Firefox |
| about:cache | Displays information about the Network Cache Storage Service |
| about:certificate | Lists certificates installed including for Servers and Authorities |
| about:checkerboard | Visualizes the rendertrace to help in troubleshooting rendering issues |
| about:compat | Lists all web compatibility modifications that are active |
| about:config | Displays advanced configuration preferences |
| about:crashes | Displays submitted crash reports |
| about:credits | Lists all the contributors that have worked on Firefox |
| about:debugging | Used for configuring remote devices for debugging with Firefox |
| about:devtools | Displays the Developer Tools useful for Web Developers |
| about:downloads | Lists all the downloads |
| about:home | Shows the configured Home page |
| about:license | Lists all the licenses under which Mozilla Firefox has been built upon |
| about:logins | Lists all the logins that are saved and synchronised |
| about:loginsimportreport | Shows the summary of all logins and passwords imported to Firefox |
| about:logo | Displays the logo of Firefox |
| about:memory | Shows memory usage |
| about:mozilla | (Easter egg) Displays a verse from The Book of Mozilla |
| about:networking | Shows all networking information and protocols operated by the browser such as HTTP, Sockets, DNS, Websockets, etc |
| about:newtab | Shows a new tab |
| about:performance | Displays all the memory and performance information about Firefox subprocesses, add-ons, and tabs |
| about:plugins | Shows information about installed plugins |
| about:policies | lists all active policies, errors (if any related to policy configuration files), and policy documentation |
| about:preferences | Shortcut command to display the Preferences page - usually accessed via the Options menu |
| about:privatebrowsing | Shortcut to switch to a Private Browsing tab |
| about:processes | Shorcut to show the Process Manager |
| about:profiles | Lists all the profiles created on the device - useful for managing different profiles |
| about:protections | Displays the Protections Dashboard. It is a personlised summary of the protections that Firefox uses, including tools for online security |
| about:rights | Lists all the rights that the users of Firefox are entitled to |
| about:robots | (Easter egg) Title of a window contains a citation from the movie, The Day the Earth Stood Still |
| about:serviceworkers | Displays all the ServiceWorkers registered in the browser |
| about:studies | List of studies that the user/browser has participated in |
| about:support | Shows technical information about Firefox that is useful as general diagnostic information and for troubleshooting errors |
| about:sync-log | Displays all the logs related to sync |
| about:telemetry | Lists all information about performance, hardware, usage and customisations collected for Telemetry service of Firefox |
| about:url-classifier | Gets a classification of a webpage from the URL only, without visiting the page itself |
| about:webrtc | Displays information about WebRTC as used by Firefox |
| about:welcome | Displays the Welcome page that is shown during the first run of Firefox after installation |
These pages are incredibly useful during development of advanced functionality for a webpage.
