Quick answer: An underline text generator adds Unicode combining underline and strikethrough marks to each character, so the line survives copy and paste. Type your text above, tap a style to copy it, and use it where an app has no formatting button. Free, no signup.
What is underline text?
Underline text made with Unicode uses combining line characters that attach to each letter you type. Instead of applying an underline style that only exists inside a document, the line becomes part of the string itself, so it survives copying into apps that offer no formatting at all. The same technique produces strikethrough font output, where a horizontal line crosses through the middle of each character, plus double underline and overline variants. This is why you can underline your Instagram bio or cross out an old price in a WhatsApp status without any editing tools.
Visual style and appearance
A single underline sits directly beneath the letters and reads as emphasis or a heading. Double underline adds a second line for a stronger, more formal marker. Overline draws the line above the text, which is unusual enough to work as a decorative divider. Strikethrough font puts the line through the centre and instantly communicates that something is cancelled, corrected or discounted. Because each line is a combining mark attached per character, spacing can look slightly uneven in some fonts, and the line may render thicker on Android than on iOS — always check the result on the device your audience uses.
Best use cases for underline and strikethrough
Underline text is useful for a heading line in an Instagram bio, a highlighted title in a Discord channel description, an emphasised phrase in a Twitter post, or a section marker in a Notion or Trello card. Strikethrough font is the natural choice for showing an old price next to a new one in a shop status, marking a completed to-do in a shared list, or making a joke by visibly crossing out a word. Both work in chat apps, forum posts and profile fields where the platform gives you no formatting buttons.
How to underline or strike through text
Type your text into the box above. Underline, double underline, overline and strikethrough versions are generated instantly. Tap the style you want and it is copied to your clipboard, then paste it into the destination app. Keep in mind that combining marks add hidden characters, so a strikethrough string is longer than it looks and may hit a character limit sooner. Also avoid underlining long paragraphs: line-heavy text is harder to read and screen readers announce the marks, which makes the content confusing for anyone using assistive technology.