What this reference measures
This is a coverage audit of the character mappings implemented by Unicode Text Tools as of August 31, 2026. It is not a claim that every operating system or app renders every result identically. The figures below describe the input characters that this site's code recognizes; a destination still chooses the font that draws those characters.
That difference matters. A converter can correctly output a Unicode character while a strict username field rejects it, an old font draws a missing-glyph box, or a screen reader announces it differently. Treat this page as an implementation reference first, then test a short sample in the actual app where you plan to paste it.
Coverage snapshot
| Style | Mapped input | Known fallback | Best use |
|---|---|---|---|
| Superscript | 26 Latin letters in either case, 10 digits, and + - = ( ) (67 mapping keys) | Most punctuation and non-Latin scripts remain ordinary | Exponents, short ordinals, footnote markers |
| Subscript | 17 Latin letters in either case, 10 digits, and + - = ( ) (49 mapping keys) | Unsupported letters stay at baseline | Formulas and indexed variables |
| Small caps | 25 lowercase Latin mappings; uppercase input uses the same shapes | x, digits, punctuation, and non-Latin text remain ordinary | Short visual labels |
| Bubble text | 52 Latin letter forms plus 10 digits | Punctuation and other scripts remain ordinary | Decorative display names |
| Upside down | Latin letters, digits, and selected punctuation | Some rotations are visual approximations | Short novelty messages |
Why subscript is intentionally incomplete
Unicode contains all subscript digits but not a full second alphabet. The available letters support selected phonetic and technical notation; they were not designed for turning every ordinary word into a lowered word. Our Subscript Letters reference shows the supported set directly. When a requested character is unavailable, the generator leaves it unchanged rather than borrowing a similar-looking symbol from another script.
This fallback makes the limitation visible to the person copying the result. It is preferable to an output that looks decorative but becomes confusing, unsearchable, or misleading. For formal equations, use an equation editor; for a compact plain-text formula such as H₂O or x₁, the available Unicode digits are a practical option.
Why small caps and upside-down text have different limits
Small caps on this site are assembled from Unicode modifier and phonetic characters that resemble reduced capitals. They are not a font feature, and there is no sensible small-cap mapping for every letter—x is the visible example in this implementation. Upside-down text has a different problem: Unicode does not provide a true 180-degree counterpart for every character, so some outputs are only visual approximations.
These limitations are why both styles are better for a brief label or joke than for important information. A user should be able to understand the ordinary wording without needing the style. Read Unicode Text vs Fonts for a broader explanation of how character substitution affects portability and accessibility.
How this snapshot was produced
The numbers above come from the mapping tables used by the site's client-side conversion code, rather than from a keyword list or a claimed device survey. For example, the superscript table has entries for the 26 basic Latin letters, creates equivalent entries for uppercase input, includes the ten digits, and maps five notation symbols. The subscript table intentionally has fewer letter entries. Bubble text is generated for the 52 upper- and lowercase Latin letters plus ten digits.
That method is useful because it is reproducible: a change to the converter must also change this reference and pass the site's publication checks. It does not measure every browser, social platform, or operating-system font. A real cross-device test would need documented hardware, app versions, screenshots, and dates; until such a study is published, this site does not claim one. The honest answer for a specific platform remains to paste a short sample into that platform.
A repeatable compatibility check
- Enter a short example containing the exact letters, digits, and punctuation you need.
- Check which characters remained unchanged; that is a coverage limit, not a hidden error.
- Paste the result into the final destination on the device you expect visitors to use.
- Keep a plain-text version for search, accessibility, and later editing.
- Use ordinary text if a character is rejected, rendered as a box, or makes the message harder to understand.
This process does not require guessing about a platform. It produces a result that is relevant to the exact field and device you intend to use, which is more useful than a generic promise that a decorative style works everywhere.