Unicode has superscript and subscript characters, but the sets are incomplete. Superscript covers digits and most lowercase letters; subscript covers digits and only about a dozen letters. The gaps are historical, not arbitrary, and they cannot be worked around.
Why the sets are partial
These characters were encoded for specific purposes — phonetic notation, mathematical and chemical formulae, ordinal indicators — rather than as a general raised-and-lowered alphabet. Characters were added when a documented need existed, so the coverage reflects those needs rather than completeness.
What is actually available
Superscript has all ten digits, though ¹ ² ³ come from Latin-1 Supplement while the rest are in Superscripts and Subscripts, which is why they sometimes differ slightly in weight. Most lowercase letters exist, largely from phonetic ranges; q is notably missing. Subscript has all ten digits and roughly a dozen letters, mainly a e h i j k l m n o p r s t u v x.
Use real markup when you can
In HTML, the sup and sub elements are correct. They are semantic, fully styleable, work with any character, and are understood by assistive technology. Unicode characters are the fallback for plain-text contexts — chat, bios, form fields — where no markup is available.
The accessibility cost
Superscript characters are not the letters they resemble. Text using them will not be found by search, and a screen reader may announce them by their phonetic names. H₂O written with a subscript two is not the same string as H2O and will not match it.
When a character is missing
There is no substitute. Some tools quietly swap in an unrelated lookalike, which produces text that is wrong in a way readers cannot see. This site leaves unsupported characters at normal size so you can tell immediately what converted and what did not.
References
Related tools and guides
Last updated September 2026 · Editorial policy · How we verify Unicode claims