Emoji to copy and paste

An emoji is text, which explains most of its odd behaviour. The same character renders differently on Apple, Google, Microsoft and Samsung devices because each ships its own artwork for the same codepoint, so the pistol that Apple draws as a water pistol is drawn as a revolver elsewhere; the character is identical and the picture is not. That is worth knowing before using one where tone matters.

Some are one character and some are several joined together. A family, a flag, and any emoji with a skin tone are sequences of codepoints held together by zero-width joiners, which is why deleting one sometimes takes several presses of backspace, why a character count disagrees with what you see, and why software that cuts a string by length can slice one in half and leave debris. Copying from here always takes the whole sequence.

One practical warning: databases. A MySQL column declared utf8 cannot store most emoji at all, that encoding tops out at three bytes and emoji need four. The column has to be utf8mb4. An emoji vanishing between a form and a page is almost always this.