Underline Text Generator
Underlined text built from combining marks, so the line travels with the words.
Type something above to see it in every style.
How an underline made of characters works
These styles do not replace your letters. They add a combining mark after each one, and a combining mark is drawn on top of the character before it rather than taking up a position of its own. Stack the low line mark after every letter and the marks join up into a continuous rule under the word.
Because the marks are part of the text, the underline travels with it into fields that have no formatting controls, which is the whole point. It also means the character count roughly doubles, which matters where there is a limit: an underlined bio uses about twice the budget of the same words plain.
Why spaces are skipped
Adding a combining mark to a space produces a short floating line with nothing above it, so the rule appears to break apart between words in some fonts and to run through them in others. Spaces are left unmarked here, which keeps the result predictable across devices. If you want the line to run unbroken through the gaps as well, use full-width or non-breaking spaces in your input.
How it works, and the one catch
These styles are not fonts. Each one is a separate block of real Unicode characters, so the styled letters travel with the text itself rather than depending on formatting the destination has to support. That is why a copied result keeps its look in a profile, a message or a post that offers no formatting controls at all.
The catch is worth knowing before you use it anywhere important. A screen reader announces the underlying code points rather than the letters you meant, so bold written in styled characters can be read out as a string of symbol names or skipped entirely. Search engines index them poorly for the same reason. Use these for a display name, a bio flourish or a post that wants to stand out, and keep ordinary letters for anything a person needs to read straight through or a search engine needs to understand.
Support varies by device. Almost everything renders on current desktop and mobile systems, but older phones and some apps substitute a box for a character they do not carry. The styles nearest the top of the list are the most widely supported, so when a result matters, prefer those and check it once on the platform you are posting to.
Questions
Why does my underline look broken between words?
Different fonts draw the combining low line at slightly different widths, so the rule can appear to break at spaces. Spaces are deliberately left unmarked, since marking them produces a floating line fragment on many devices, which looks worse.
Does underlined text use more characters?
Yes. Each letter gains one combining mark, so an underlined line uses roughly twice as many characters as the plain version. That matters wherever there is a length limit, such as a bio or a display name.
What is the difference between underline and strikethrough here?
Only which combining mark is added. The low line mark sits under the character and the long stroke overlay sits across it, but both work the same way and both survive a paste equally well.
Will this work on every platform?
Almost everywhere, though a few apps normalise combining marks away or render them offset. Paste a short test into the destination before committing a long line to it.
Is my text sent to a server?
No. Everything runs inside your browser and this tool has no backend, so nothing you type is transmitted, logged or stored.
Related: Strikethrough Text Generator and the full Unicode Text Converter. Everything else is on the all tools page.
Related tools
Browse all Sigma Wire tools - every free tool on the site, grouped by category.