aestheticsymbols
Use in a combo

Superscript k copy & paste

ᵏ is superscript k, a plain-text Unicode symbol from the Phonetic Extensions block. On Aesthetic Symbols it lives in the tiny & superscript collection. As plain text it takes on the font and colour of wherever you paste it — a bio, a username, a caption or a stream title.

Unicode
U+1D4F
HTML entity
ᵏ
CSS content
\1D4F
JavaScript
\u{1D4F}
UTF-8 bytes
E1 B5 8F
Made of

U+1D4F ᵏ · Phonetic Extensions

Will it show up? · Long-established text symbols

Plain-text characters from blocks that mainstream desktop and mobile fonts have covered for years. These are the safe ones.

Worked out from how each character is encoded, not from a test on a real device.