The surprisingly complex reason you never see emoji URLs
washingtonpost.com
washingtonpost.com
Here's an example from the RFC: https://tools.ietf.org/html/rfc3492#section-7.1
Unicode: 他们为什么不说中文
DNS: xn--ihqwcrb4cv8a8dqg056pqjye
utf8 base64: 5LuW5Lus5Li65LuA5LmI5LiN6K+05Lit5paH
Let's see if HN will link these:http://.ws -> http://xn--ls8h.ws/
edit: Nope, it strips (!) emoji from comments.
It's a fun thing, but not very practical. Not even I can remember which variation of smiley I used, plus different devices render them differently so it can be hard to remember or recognise.
I would only use it as a gimmick right now, where I can use short URLs in say tweets.
We have non-latin TLDs now, so I don't buy this.