Turn letters and digits into subscript characters that sit below the baseline — the standard way to write chemical formulas in plain text.
| Input | Output |
|---|---|
| H2O (Subscript) | ₕ₂ₒ |
| CO2 (Subscript) | cₒ₂ |
| log2 (Subscript) | ₗₒg₂ |
Subscripts are the correct way to write formulas and indices in plain text: H₂O, CO₂, C₆H₁₂O₆, log₂, aₙ. In a word processor, use the editor's own subscript button so the text stays easy to edit; use this tool for chats, posts, usernames on forums that allow it, and plain-text documents.
The letters b, c, d, f, g, q, w, y and z, plus every capital letter, have no subscript codepoint in Unicode. They are returned unchanged so the word stays intact instead of turning into pictures or lookalike symbols.
Type H2O and convert: the H stays normal and the 2 becomes a subscript ₂. The same pattern gives CO₂, O₂ and CH₄. Only the number needs to be subscript in most formulas, though letters can be converted too where the glyph exists.
Subscript characters are deliberately drawn smaller and lower. In a large bold setting that reads fine; in a light font at 12px it can become too faint. If readability matters, use the editor's own subscript feature instead of Unicode characters.
Yes — a common case is a charge and an index together. Convert the parts separately and paste them next to each other; the two character sets are independent.