As others have said, emoji are just unicode. What's interesting is that the some aren't just a single unicode character. For example, where skin tone is availab

As others have said, emoji are just unicode. What's interesting is that the some aren't just a single unicode character. For example, where skin tone is available for some emoji (e.g. Santa) it is represented as the generic emoji, plus a separate character representing skin colour. The client has to interpret this to show the intended glyph. Instagram engineering covered this quite nicely [1]. [1] https://instagram-engineering.com/emojineering-part-ii-implementing-hashtag-emoji-7b653b221c82 https://instagram-engineering.com/emojineering-part-ii-imple...