I made a Safari extension that simulates favicons by prefixing tab titles with emoji. It's not a perfect substitute, but it's made it a lot easier for me to distinguish between tabs.
Out of curiosity, how does it know which Emoji to use?
so you don't even read 15 lines of readme?
That type of response probably won't get too many people rushing to your GitHub that you are suggesting here people should try out. To answer his question, it appears it allows you to manually add/choose a emoji on a site by site basis. As of December it looks like you can now set differently for different subdomains or other variations. Also appears to offer some suggested options to choose from for popular sites.