You can use a file userChrome.css to add an icon to tabs where the site doesn't provide one. If you want to pursue that, I can provide you with the code I use. You can choose the image you want to use. I have used .ico, .jpg and .png images. (Remove the blank space in the link below.)

WARNING: This script is not provided by Mozilla and is not officially supported Creating a userChrome.css file and other ways of customizing Firefox that are not exposed in the interface are there for developers, not end-users. If it were intended for end-users, you would see a menu option or checkbox; you wouldn't have to hack a text file in a hidden location.

What this means is that even though the functionality you want is no longer supported, a third-party has found a way to do it using the CSS file. If it breaks in new versions, you will need to contact the person who provided the script.

[Warning added by moderator.]

https://www.userchrome. org/how-create-userchrome-css.html

I have a userChrome.css folder already, that works great! I would love the code you use, if you don't mind. Then I can mark as solved.

Hi. I have only just seen your reply. The code follows. If you put the image you want in the chrome folder, you only need the name of the file as the url. If the image is elsewhere, you need to put the full path and name. (Remove the blank space in the link.)

.tab-icon-pending:not([pendingicon]) + .tab-icon-image:not([busy]){ display: -moz-box !important; }
.tab-icon-image:not([src]){ content: url("image.jpg") !important; }

https://www.reddit. com/r/FirefoxCSS/comments/ti9wla/create_tab_favicon_not_working_with_ff_9801/