A "font generator" like this site does not apply a typeface to your text the way a word processor does. It swaps each letter for a different, genuine Unicode character that a font renders as something that looks bold, cursive, or otherwise styled. The output is text, not an image, which is exactly why you can paste it into a bio, a caption, or a username field and have it travel anywhere plain text goes.
Where these characters actually come from
Unicode, the standard that assigns every character in every language a unique number, includes a block called Mathematical Alphanumeric Symbols. It exists to let mathematicians write things like a bold vector variable or a blackboard-bold "ℝ" for real numbers in plain text instead of an image. That block happens to contain a complete bold alphabet, a complete italic alphabet, a monospace alphabet, and several more, fully by accident of what mathematical notation needed.
Stylish-text tools repurpose that block (and a handful of others, like the letterlike-symbols block that scatters in odd survivors like italic "ℎ" and script "ℯ") for decoration instead of math. That is also the ceiling on how many "fonts" a site like this can ever offer honestly: Unicode contains a finite number of complete Latin alphabets, full stop. Once the mathematical block and the borrowed-script lookalikes (Cyrillic, fullwidth, and so on) are used up, there is no further alphabet to add. Sites advertising "200+ fonts" are combining that modest, finite set of alphabets with decorations (separators between letters, frames around the whole word), not discovering new ones.
Why some styled text shows as a box
A font on your device has to actually contain a drawing for each Unicode character to display it. Most system fonts cover the common alphabets well, but a rarer character can fall outside what a given app's font supports, and you get a small box (☐), sometimes called "tofu," instead of the intended glyph. This is why a name that looks perfect in a generator can render as boxes once pasted into a specific game or app with a narrower font. It is not a bug in the text; it is a font on the receiving end that does not draw that particular character.
The trade-off worth knowing
- Compatibility varies by platform. A well-supported block (bold, italic, fullwidth) tends to render correctly almost everywhere. A rarer one is more likely to show boxes somewhere.
- Search and accessibility both read the literal character, not what it resembles. Styled text is generally not matched by search, and screen readers can pronounce or skip decorative characters unpredictably. Reserve styling for accents, not for anything a person or a search engine needs to find or hear correctly.
- A styled character is a different character, not a different rendering of the same one. That is a feature for getting past a "name already taken" check and a limitation for anyone trying to search you by your styled name.
Where to see the range
The site groups the underlying alphabets by look and use case: cursive, bold, small caps, bubble, and the full catalogue at the fonts hub. Every one of them is built from the same idea explained here: a real, finite alphabet, borrowed from a corner of Unicode it was never designed for, repurposed for decoration.