Free generator, copy and paste
Subscript generator H₂O, CO₂, xₙ
Lowered digits and letters for chemistry, maths and footnotes, as plain text that pastes into any app.
- subscript
- superscript
Updated · strikethroughtext.online
How this works
Every digit, and the letters that have a subscript form in Unicode, are swapped for their lowered versions. Capitals and unsupported letters pass through unchanged. That’s the right behaviour for chemistry, where the element symbols stay full size and only the counts drop: type C6H12O6 and you get C₆H₁₂O₆.
The second result is superscript, because the two often travel together. An ion such as SO₄²⁻ needs both: subscript for the four oxygen atoms, superscript for the charge. Build it in two passes and copy the pieces.
Where subscript gets used
Chemistry. Molecular formulas are the main reason people look for subscript: H₂O, CO₂, O₃, NaHCO₃. In a chat, a forum answer or a slide title, H₂O reads correctly where H2O looks like a typo.
Maths and physics. Indices and sequence terms: x₁, x₂, aₙ, vₜ. Variable names in a plain-text explanation stay readable without LaTeX.
Notes and labels. Version tags (v₂), log bases (log₂ 8 = 3) and lowered markers in a list.
The missing letters
Unicode’s subscript set is uneven. Digits and the basic operators are complete, but only 17 lowercase letters exist, and there are no capitals. That’s a historical accident: the letters were added for phonetic transcription, not for typesetting. So xₙ works and y_b doesn’t. If you need a full subscript alphabet, you need real formatting, which means a document editor.
Subscript in documents
If you’re writing in Word, Google Docs, Pages or a slide deck, use the editor’s own subscript button or shortcut instead. Formatted subscript works for every character, matches the font of the surrounding text and is read correctly by screen readers. Use this generator when the text has to leave the document: a chat message, a spreadsheet cell, a file name or a social post.
One practical tip: subscript digits are separate characters, so search won’t find H2O if you typed H₂O. In anything people will search, like a product listing, write the plain version somewhere too.
Questions people ask
Why are some letters not converted to subscript?
Unicode only has subscript forms for 17 lowercase letters, added for phonetic notation. There is no subscript b, c, d, f, g, q, w, y or z, and no subscript capitals at all, so those characters stay as they are.
How do I write H2O with a small 2?
Type H2O into the box and copy the result: H₂O. The generator converts every digit to subscript and leaves capital letters alone, which is exactly how chemical formulas are written.
What is the keyboard shortcut for subscript?
In Microsoft Word, select the text and press Ctrl + = (Cmd + = on a Mac). In Google Docs it is Ctrl + , (Cmd + , on a Mac). Those shortcuts only work inside the document; anywhere else, use the copy-and-paste version.