Does Not work at all. Tried refreshing, changing urls etc.

doesnt always work directly (sometimes must refresh) but then it's a really good help

Love it, exactly what I needed.
Accepts any sort of picture I tried, not just .ico
Would be great to have some built in icon replacement options.

So here's how I got this extension to work.

1. Click the extension on an open website
2. Select the particular favicon you want. The URL will automatically be copied
3. Open the properties for the particular bookmark you want to use.
4. Paste the favicon URL into the URL of the bookmark and hit save
5. Reload the webpage so that the favicon image is displayed on the screen
6. Now replace the URL of the bookmark to the ORIGINAL URL
7. Click the bookmark.

Unfortunately did not work. I tried several times to customize a Gmail URL to show only starred items in my inbox with a star icon, but it kept overwriting it with the regular Gmail envelope icon. Disappointing.

Great experiment! Do not stop!
An incredibly useful tool for optimizing workspace, completely solves the problem with chaos in the tabs, when they do NOT have their own favicon.

It works but not for any form of wildcards.

Meaning that you can't make ONE rule to change the icon of:
- mail.google.com
- dev.google.com
- special.dev.google.com
- search.google.com

Allowing the user to make a rule for *.google.com is really needed for this extension to be useful. Chrome extensions already offer this feature.

Works OK-ish. It seems to show my custom icon only when I refresh the page. On new page, or after fresh Firefox start, it shows the original favicon again (on pinned bookmark for example). Would be awesome if my custom icon always had priority over the original one.

Also, it would be great if I could enter the URL with regular expressions like *.website.com/* to the URL bar in the options.

Great add-on. Just go into addons and then preferences to configure

Schade dass es noch so umständlich ist, aber wenigstens funktioniert es. Wenn jemand ein besseres Plugin hat, gerne her damit ;-)

This addon does work and it's wonderful

great idea but simply does not work

There are no instructions. I thought you would right-click on a bookmark to change the favicon. Instead, you need to first open the favicon-customizer add-on. Near the bottom right of the page, there is an area you use to type in the webpage name and link a favicon. Took me a while to find this. I've tried to make the add-on work but so far I can't make it work in Firefox 60.0

Hubiera sido buena si me hubiera funcionado. Tengo Firefox 59.0.2 x64 en Windows 7 x64.
Adjunto video donde se puede ver que no cambia el icono ni el título de la página.
https://drive.google.com/open?id=1hRCwR7VxfMriIKP29_9d3FAwRcuOFkoT

¿Se podrá corregir?
Gracias!
----- 29/11/2018
Intentando nuevamente con la versión de Firefox 63.0.3 (64-bit) y aún no funciona del todo. Sólo cambia el icono si es que no hay "Nombre" ni "Título de página", pero sólo dura un momento, luego se pone el icono original del sitio web. Además, no se puede cambiar el título de la página.
-----

Great add-on, works just as shown, including in the new WebExtensions versions of Firefox. Thanks!!!

It works for me, it would be nice if you could right-click into a bookmark and change the icon from there, though.

Quantumになって、ファビコンカスタマイズのアドオンが見つからず、残念に思っていましたが、
このアドオンでカスタマイズがまた可能になりました。使い勝手も良いと思います。

1）ファビコンをカスタマイズしたいブックマークのURLをコピー
2）アドオンの詳細画面でURLの欄にCtrl+Vでペースト
3）png形式の画像をcustom faviconの欄に選択した後
4）ファイアフォックスを再起動
5）ファビコンを変更したブックマークを選択してホームページを表示することで
新しいファビコンイメージが表示されます。