Superscript, Subscript and Tiny Text Explained

What superscript and subscript are

A superscript sits slightly above the normal line of text and a subscript sits slightly below it, both usually in a smaller size. They are everyday typographic tools. Writers use superscripts for exponents such as m², ordinal endings and footnote markers, and subscripts for chemical formulas such as H₂O. Typesetters have used raised and lowered text for these jobs for a long time, and word processors and web pages still treat it as a basic formatting feature.

How Unicode handles tiny characters

Unicode includes dedicated small characters, but they were added at different times and for different reasons, which explains the patchwork. The Superscripts and Subscripts block (U+2070 to U+209F) has digits, a few signs and some letters. The superscripts ¹, ² and ³ are not in that block because they were inherited from an older standard, ISO 8859-1, and live in the Latin-1 Supplement. The Superscripts and Subscripts block was part of Unicode 1.0 in 1991, and later versions added letters needed for phonetic notation, such as the Uralic Phonetic Alphabet.

Which letters exist

The supply is uneven, so tiny text generators handle gaps in different ways.

• Superscript digits 0 to 9 and the signs +, −, =, ( and ) are available.
• Subscript digits 0 to 9 and the same signs are available.
• Only a few subscript letters exist: ₐ, ₑ, ₒ, ₓ, ₔ, ₕ, ₖ, ₗ, ₘ, ₙ, ₚ, ₛ and ₜ in the main block, with a handful of additions in newer Unicode versions.
• Superscript letters mostly come from other blocks, such as Spacing Modifier Letters (which has ʰ and ʷ) and the Phonetic Extensions blocks, because those blocks were built for phonetic notation.
• Small caps are likewise borrowed from phonetic blocks, so a few letters may be missing or may look slightly different from the rest.

Why your tiny text may look uneven

Because the characters come from several blocks, a tiny word may mix letters from different fonts on your device. One letter may look slightly larger, lower or lighter. If a letter has no tiny version, a tool may leave it normal-sized or skip it. This is a limit of Unicode’s coverage, not a mistake in your text. Short strings of numbers and a few letters usually look best.

When to use real formatting instead

In a document, web page or spreadsheet, use the built-in superscript and subscript formatting rather than tiny Unicode characters. Real formatting keeps the underlying letters and digits normal, so search, spell check, copy-paste and screen readers see what you meant. On the web, the HTML sup element is meant for typographic raised text such as exponents, superior lettering and ordinal numbers, and MDN recommends other methods, such as CSS, for purely decorative raised text. For combined or complex notation, such as a chemical isotope with both mass and atomic numbers, MDN points to MathML.

Tiny Unicode characters are best for places that have no formatting controls, such as a bio, a username field that allows symbols or a chat message, and for decoration rather than information. Keep formulas, units and anything someone may need to search or read aloud in plain text or real formatting.