How to change the main window icon of Firefox 26 and above

Firefox is truly a very customizable browser. It has lots of hidden features and options which are not accessible via the browser's preferences UI. Add-ons enable many of these features to be customized in a user friendly way. Others can be tweaked with the built-in configuration editor (about:config). One such secret feature of Firefox is the ability to change the icon of the main window and bookmarks as well as library windows. You can even set your own icon for the downloads library, the bookmarks window, and the view source tool without using any third party tools. Let's see how it can be done.

Modern versions of Firefox have a built-in, native option to define user-specified icons for most of its window types. We can use this feature to customize Firefox icons.

Right click the Firefox icon on your desktop and choose 'Open file location' to open the File Explorer application right at the Firefox installation folder path:

Open file location By default, Firefox is installed to the 'C:\Program Files (x86)\Mozilla Firefox' folder for 64-bit versions of Windows and into 'C:\Program Files\Mozilla Firefox' for 32-bit Windows.

Here you can see the 'browser' folder. Open it and create the 'chrome' subfolder. Note that you might get a UAC confirmation request. Just allow it:

UAC the browser-chrome folder Inside the chrome folder, create an 'icons' subfolder. Again, approve the UAC request by clicking Continue. After that, create a 'default' subfolder inside the icons folder. You should achieve the following path:

C:\Program Files (x86)\Mozilla Firefox\browser\chrome\icons\default

icons folder path Close your Firefox browser.

Put icons which have the following names inside the 'default' folder you create above:

  • main-window.ico - an icon file for the main window
  • downloadManager.ico - an icon for the downloads library window
  • viewSource.ico - an icon for the 'View Source' tool window
  • places.ico - this icon will be used for the 'Bookmarks' window
  • printPageSetupDialog.ico - this icon will be used for the print setup window
  • Wizard.ico - this icon is used for the various settings wizards, i.e. Setup Sync wizard. Note that this icon will be displayed only in the taskbar, since the Setup Sync window does not have any icon in the title.
  • BrowserPreferences.ico - this icon will be used for browser preferences and also will be displayed only in the taskbar
  • default.ico - this icon file is used in case the browser displays some window without a defined icon, i.e. a window from some add-on. Note that many add-ons have an icon defined. For example, the popular Tab Mix Plus add-on uses the following icon file for its preferences window: TabMIxPreferences.ico.
  • CustomizeToolbarWindow.ico - this icon is used for the customization preferences of toolbars.
  • unknownContentType.ico - this icon is used for the 'Opening...' dialog.
  • openLocation.ico - this icon is used for a special dialog box which appears on the screen only if you have removed the location text field from the navigation toolbar.

Let's place some colorful icons in our 'default' folder to see these customizations in action. I will use the following icons:

custom firefox icons Put all the icons you need and run Firefox. The result will be as follows:

custom icons in action

11 thoughts on “How to change the main window icon of Firefox 26 and above

  1. Sergei

    Can we do this customization at the profile level? I want to have different icons for every Firefox profile. Right now I accomplish this by making a copy of FF installation folder for every profile, but hopefully there is a more efficient way.

    1. Sergey Tkachenko Post author

      Unfortunately, I have no idea.
      I discovered this ability with ProcMon, it looks like you cannot customize icons per user profile without using third party tools or adddons.

    1. Sergey Tkachenko Post author

      You are welcome

  2. Noitidart

    Very nice! Can you please share where we can get those colorful icons you have they are beautiful!

    1. Sergey Tkachenko Post author

      Try here:

  3. BB

    Is there a way to do this in the PortableApps builds?

    1. BB

      nvm found path for PA builds;

  4. Glyn Duggan

    A Google search suggested your site had a comment on my problem, but I can’t find it.

    The problem: since installing Win 10 the taskbar icon for Firefox has changed from the familiar ‘fox clasping the globe’ to a generic ‘document’ (ie vertical rectangle with the top right corner dog-eared). How can I change this back to the ‘proper’ one?

  5. Anony Mous

    In an attempt to restore the original Firefox icons from Firefox 56.0.2 in Firefox 57, I followed your instructions at the url listed above and did not get any change whatsoever. I believe at least a couple of steps may have been omitted from your online instructions.

    1. Sergey Tkachenko Post author

      This trick does not work in Firefox 57.
      Look at the article date.
      It utilizes the XUL UI, you could notice it.
      It doesn’t exist in Firefox 57, which comes with Photon UI.


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