U+1D400 The Unicode codepoint the style's characters come from. Two styles can look almost identical and still be different characters with different device support. The codepoint is the only reliable way to tell which one you copied.
IGTTRB Platform support. Green renders reliably. Amber works, but breaks on some devices or in some fields. Struck through is filtered out or rejected by that platform.
IG Instagram · TT TikTok · DC Discord · WA WhatsApp · FB Facebook · X (Twitter) · RB Roblox
The same style inside each frame. Type above and these update with it, then tap to copy the whole thing. The number is the character count, which matters if you are pasting into a field with a limit.
Underline works the same way strikethrough does. It keeps your letters and attaches an invisible combining mark, U+0332, beneath each one. That shared mechanism means it shares strikethrough's main advantage: your original letters survive underneath, so the text stays searchable and a screen reader still reads real words.
It has one problem strikethrough does not. A strikethrough line crosses the middle of a character, where nothing else is competing for the space. An underline sits below the baseline, which is exactly where descenders live. Letters like g, j, p, q and y drop into that zone, and the mark has to be drawn through or around them. Different text engines resolve that collision differently, and none resolve it well. A word with several descenders will look noticeably rougher than one without.
The practical test is your own text: underline reads cleanly across something like 'stable' and messily across something like 'jargon'.
As with strikethrough, output is roughly twice as long in characters as it looks, since every visible letter carries a hidden mark. Against a bio character limit that halves what you can write.
Where it earns its place is WhatsApp, which offers bold, italic, strikethrough and monospace but no underline at all. On most platforms a native underline will beat this; on WhatsApp there isn't one.
Words without descenders, and WhatsApp.
The first is a real constraint rather than a preference: the mark sits exactly where the tails of g, j, p, q and y already are, and no text engine resolves that collision cleanly. Test your actual text rather than a sample, because 'stable' and 'jargon' produce very different results.
The second is where it earns its place. WhatsApp offers bold, italic, strikethrough and monospace, and no underline at all. Everywhere else a native underline will beat this; on WhatsApp there is not one.
As with the other combining styles, output is roughly twice its visible length, which against a bio limit halves what you can write.
Descenders. The mark sits below the baseline, which is where the tails of g, j, p, q and y already are, so the two collide. Text engines handle that collision differently and none handle it well. Words without descenders render noticeably more cleanly.
Yes. Like strikethrough, it adds marks rather than replacing letters, so your original text is intact underneath. It stays searchable and a screen reader reads real words. Substitution styles like bold and script lose both.