All domains are ASCII text, including Emojis. Some browsers may display the Emoji or IDN (Internationalized Domain Name) characters within the address bar, but behind-the-scenes the domain remains in ASCII text.

Browsers use "punycodes" to convert the domain name "?.fm" to "xn--xu8h.fm" in the back-end.

While you can type in the Emoji characters into the address bar and the domain will resolve properly, some browsers may only display the ASCII text version of the domain within the address bar.