Subscript Generator

This subscript generator converts digits and a few letters into tiny lowered Unicode characters, such as H₂O, CO₂ or aₙ, that you copy and paste into a chat, bio, spreadsheet cell or plain-text email. It works best for chemistry and maths indices, and runs in your browser.

How to use the subscript generator

1. Type only the part that should drop, such as the 2 in H2O, in the box at the top.
2. Check the Subscript row; the digits row shows number-only subscripts.
3. Tap Copy and paste it between your normal letters, as in H₂O.

What this generator is for

Subscript is the lowered, smaller text in H₂O, CO₂ and the indices in x₁, x₂, xₙ. People search for a subscript generator because chat boxes, bios, spreadsheet cells and plain-text emails have no formatting buttons. This tool swaps the characters you type for Unicode subscript characters, which are drawn small and low, so the result survives a copy and paste.

The honest summary: subscript works very well for digits and signs, and poorly for words. Almost every real use of subscript is a number.

Chemistry and maths examples

Convert only the part that must drop. If you run H₂O through the generator whole, the capital H changes too, and the formula is wrong.

The 17 letters, and every gap

Unicode has subscript forms for exactly these letters: a e h i j k l m n o p r s t u v x.

The set was not planned as an alphabet. Most of it sits in the Superscripts and Subscripts block, but ᵢ ᵣ ᵤ ᵥ come from the Phonetic Extensions block and ⱼ from Latin Extended-C, each added at a different time. Because of that history, fonts often draw them at slightly different heights and sizes.

There is no subscript for b c d f g q w y z, and none for capitals, which is why the generator turns capitals into the lowercase subscript when one exists and leaves other letters alone. A word like “bridge” would convert as bᵣidgₑ, which is useless as text. That is why this page does not pretend to be a general text style.

Digits are complete: ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉, and the signs are ₊ ₋ ₌ ₍ ₎ (U+208A to U+208E). All of them live in the Superscripts and Subscripts block, so unlike superscript digits they come from one source and tend to match each other.

Formulas to copy

Typing the subscripts in a few standard formulas is quicker if you can see them whole:

Notice that only the small numbers drop; the coefficients in front (6CO₂) stay full size, and the parentheses in Ca(OH)₂ are ordinary brackets, since only the 2 is a subscript. If you need parentheses inside a subscript itself, such as in an index like x₍ₙ₊₁₎, the generator provides ₍ ₎ ₊ ₋ ₌.

In maths

Subscripts label variables rather than change their value: x₁, x₂, x₃ are three different quantities, and aₙ is the nth term of a sequence. The letter indices that exist (i, j, k, n, m, p, r, s, t, u, v, x and the vowels a, e, o) cover most conventional index names, which is why subscript works well here despite its gaps. Names such as b₍c₎ cannot be done because b and c have no subscript, so write those as plain text with an underscore, b_c, which is also what plain-text maths usually does.

Real subscript formatting

For anything that is a document rather than a bio, use the app’s formatting:

• Microsoft Word: Ctrl+= (Windows, long-standing); Microsoft’s current list names Ctrl+Shift+Minus (Windows) and Cmd+Shift+Minus (Mac). Try the other if one fails.
• Google Docs: Ctrl+, (Windows/Chromebook) or Cmd+, (Mac).
• HTML: the <sub> element.

Real formatting keeps the underlying text intact: a search for “CO2” finds CO₂ typed that way, and a screen reader says “C O two”. Pasted subscript digits are separate characters. Searching for “H2O” will not find “H₂O”, and a screen reader may announce “subscript two”. The Unicode version is for places that strip formatting: social bios, display names, game names, commit messages, plain-text email.

Scientific journals and chemistry software expect real formatting for submissions, so treat the Unicode form as a convenience for informal writing.

Pasting formulas safely

• Check the font. Subscript digits are in nearly every modern font, but the letters ₕ ₖ ₗ ₘ ₙ ₚ ₛ ₜ are newer (Unicode 6.0, 2010) and may show as boxes on older devices. For anything someone must read reliably, stick to digits.
• Avoid mixing sources. Do not combine a pasted ₂ with real subscript formatting in the same formula; the sizes will not match.
• Keep the plain version nearby. If a reader’s device shows boxes, the plain “H2O” is a fallback. The fancy text to normal converter turns subscript back to plain digits in one click.

Under NFKC normalization, subscript characters fold to their plain forms (₂ becomes 2), which is how search and conversion tools can undo them.

Where it fits among the small styles

Subscript is one of three small-text families. Superscript covers every letter and digit, and is the right choice for exponents and footnotes. Small caps cover nearly the whole alphabet at lowercase height and are the best choice for a quiet, decorative look. The small text generator shows all three together, and the number font generator puts subscript digits next to circled, double-struck and fullwidth styles. Use subscript where it earns its place: formulas, indices and base notation.

For formulas and indices in places with no formatting, the subscript generator does what it is good at; for any real document, use the subscript formatting your app already has.