Friday, July 29, 2011

Firefox's about: commands (and easter eggs!)

Firefox (and other browsers) have a special URI scheme to display internal pages, or built-in functions. These commands start with an "about:" followed something, for example - "about:blank" displays a blank page.
These commands can be quite handy sometimes. For example, yesterday, I was searching for how to use the "sync tabs" feature of  Firefox 4 and 5. I knew how to enable tabs sync, but I did not know where I could access the synced tabs. Of course, if I had just gone through the menu, I would have found it under "History > Tabs from Other Computers". But, Firefox 4 and 5 have their menu bars hidden by default, and so I searched online and came upon another way to do that: just type "about:sync-tabs" in the address bar (without quotes), and there are your tabs.

So, I decided to find a list of all about: commands which can be used in Firefox. And I found some easter eggs among them. Here are the commands that I found to be working on my version of Firefox:

Easter Eggs:
  • about:mozilla
    Shows a verse from the fictional Book of Mozilla.

  • about:robots
    Try it in your own browser, or see the screenshot below.

General Information Pages:
  • about:
    Shows information about Firefox.
  • about:blank
    Shows a blank page
  • about:home
    Shows the Firefox home page with a Google search bar.
  • about:addons
    Shows the addons page
  • about:sync-tabs
    Shows tabs synced from other computers (tab syncing has to be enabled).
  • about:sync-logs
    Shows the sync logs
  • about:credits
    Shows credits
  • about:license
    Shows the Mozilla Public License.
  • about:rights
    Shows licensing information and your rights.
  • about:logo
    Shows the logo used on the about: screen.
    Advanced Information Pages:
    • about:plugins
      Shows installed, currently enabled plug-ins.
    • about:buildconfig
      Shows the arguments and options used to compile the Firefox build in use.
    • about:cache
      Shows information about the data in the browser cache.
    • about:cache?device=disk
      Shows the disk cache device info, keys, and data.
    • about:cache?device=memory
      Shows the memory cache device info, keys, and data.
    • about:crashes
      Shows details of crashes submitted by Mozilla's crash reporter.
    • about:memory
      Shows memory usage.
    • about:config
      Shows the firefox configuration page with a lot of configuration options.
    • about:support
      Shows troubleshooting information.
    Other Pages:
    • about:privatebrowsing
      Can be used to switch to private browsing mode. 
    • about:sessionrestore
      Shows an interface for viewing about last session.
    • about:blocked
      Shows the malware protection page used when the browser identifies a page as not safe for viewing.
    •  about:certerror
      Shows the error page used when an SSL/TLS certificate is untrusted or otherwise invalid.
    • about:feeds
      Shows the page used when clicking the rss feed icon in the address bar.
    • about:neterror
      Shows the error page used when the browser could not access the requested path.

    Update : Check my new post for some more "about" commands.

    If I missed something, you can let me know in the comments.

    Also check :


      1. Complete List of Firefox Chrome:// Commands:

        Shows the Firefox "about" Page

        Shows the "open" page

        Opens the "Options" page

        Shows the "Bookmark" page

        Shows the "History" page

        Opens the Javascript console

        Opens the "Add-ons" page

        Closes the current tab in or the Firefox window if there is only one tab open

        Opens the "Clear History" page

        Shows the "Options" page

        Opens the "Permissions" window

        Shows the "Language selection" page

        Shows the "Font Selection" page

        Shows all the "cookies"

        opens the "Connection Settings" page

        Shows the "Color Selection" page

        Shows "Advanced Script Settings" page

        Shows the "Import Wizard"

      2. Replies
        1. Already mentioned in the follow up post by us. Thanks for the tip though. Appreciate it :)

      3. about:accounts
        Sync-Account Creation


        can be the login for sync ;)

        best regards

      4. about:preferences, but I was looking for hsts clear about page.


      Your feedback is always appreciated. We will try to reply to your queries as soon as time allows.