Note: This feature was removed at Firefox 67. See also bug 1531836 for more details.
Starting with Firefox 1.5, Thunderbird 1.5, and XULRunner 1.8, you can specify an icon for a XUL window by putting files named
mywindow.ico (for Windows) and
mywindow16.xpm (Linux), where
mywindow is the
id of the
<window> you want to attach the icon to, in the
chrome/icons/default subfolder of your bundle.
These icons will override the global icon files, which are located in
Note: The global icons override does not currently work due to bug bug 543490. Global icon files currently take precedence and bundles are only searched for icons which are not provided by the application.
Starting with Firefox 3.0, XULRunner 3.0, Thunderbird 3.0 and SeaMonkey 2.0 you can now specify PNG format icons instead of XPM format on Linux. You can specify up to 4 different sizes of PNG icons using the suffixes
To support older applications, such as Firefox 1.0, you need to copy the icons to
app_dir/chrome/icons/default manually on the first start (example code).