Subscript Generator | Unicode Subscript for Letters & Digits
Convert text into Unicode subscripts. Supports letters with available forms, digits 0–9, and chemistry mode for formulas like H2O → H₂O.
Tool Purpose & Audience
The Subscript Text Generator converts letters and digits into their Unicode subscript equivalents — small characters positioned below the baseline, like the "2" in H₂O or the "n" in xₙ. The result is plain text that can be pasted into any platform without HTML or CSS.
Scientists, students, chemistry teachers, and technical writers use this tool to write chemical formulas, mathematical sequences, footnote references, and phonetic notation in plain-text contexts — Discord, Reddit, Twitter/X, word processors with limited formatting, and plain-text databases where <sub> tags are stripped.
Real-World Use Cases
- Chemical formulas: Write H₂O, CO₂, H₂SO₄, or C₆H₁₂O₆ in plain-text posts, chat messages, or spreadsheet cells where chemical formula fonts aren't available.
- Mathematical sequences: Express x₁, x₂, x₃ or aₙ notation in technical forum posts, README files, or messaging apps where LaTeX isn't rendered.
- Phonetics and linguistics: Some IPA and phonetic notation uses subscript characters that are more accurately represented with real Unicode subscript than with CSS styling.
- Footnote markers in plain text: Add subscript reference markers (₁, ₂, ₃) to plain-text documents, emails, or chat messages where footnote formatting isn't supported.
Practical Input → Output Examples
1. Chemical formula
Input: "H2O" (digits mode)
Output: "H₂O"
Digits-only subscript mode — letters stay normal, digits become subscript. Perfect for formulas where only numbers should drop below the baseline.
2. Mathematical variable with index
Input: "xn" (letters + digits mode)
Output: "ₓₙ"
Both letters and digits subscripted — useful for variable sequences like xₙ when you want the full term in subscript form.
3. Chemistry mode (compound formula)
Input: "C6H12O6"
Output: "C₆H₁₂O₆"
Chemistry mode subscripts only the digits between letter groups — ideal for molecular formulas like glucose.
Common Mistakes & Misunderstandings
Not all letters have Unicode subscript equivalents: Unicode includes subscript forms for a limited set of letters (a, e, h, i, j, k, l, m, n, o, p, r, s, t, u, v, x). Letters like b, c, d, f, and others don't have dedicated subscript code points and will pass through as regular characters.
Different from CSS subscript: HTML's <sub> element shrinks and lowers any character. Unicode subscript uses specific glyphs designed to sit below the baseline — but only where those glyphs exist in the Unicode standard.
Font coverage matters: Unicode subscript characters exist in the standard but not all fonts include their glyphs. A system with a rich Unicode font (like Noto Sans) renders them perfectly; devices with sparse font coverage may show blank boxes.
Chemistry mode ≠ automatic formula parser: Chemistry mode applies subscript to digit runs between letters, but it doesn't understand molecular structure. For complex formulas with parentheses or charge indicators, you may need to manually check the result.
Why don’t all letters have subscript?
Unicode only defines subscripts for a limited set of Latin letters. Unavailable characters remain unchanged to preserve readability.
How does chemistry mode work?
It detects letter+number patterns and converts the numeric part to subscript, keeping the letter as-is (e.g., H2O → H₂O).
Will subscripts copy correctly?
Yes. Subscripts are regular Unicode characters and copy/paste across browsers and apps that support these glyphs.
Is this different from Small Text?
Small Text offers small caps, superscripts, and subscripts together. This tool focuses specifically on subscript with chemistry targeting.