Adding a custom
favicon is simple:
Create and place a
favicon.ico file in the root (ie: “public_html” or “httpdocs” etc) directory of your web server, using your FTP program.
Zen Cart provides one by default, so simply replacing that file is fine.
In most cases, that’s all you need to do !!!
The icon image file needs to be “square”, ideally a multiple of 48x48px, such as 48x48 or 96x96 or 132x132px.
NOTE: You will usually have to “bookmark” your store in your browser’s favorites in order for the favicon to be cached by the browser for display. Often pressing CTRL+D will quickly bookmark the page you’re currently viewing.
TIP: If your favicon is cached with an old/invalid image, you can fix that after uploading your replacement by simply clearing your browser’s cache.
Related reading: https://support.google.com/webmasters/answer/9290858