What is Unicode combining underline?

Unicode combining underline (U+0332) is a special character that adds an underline beneath the preceding character. Unlike traditional underline formatting that requires application support, this combining character physically attaches to letters and travels with them when copied and pasted. The result is text like t̲h̲i̲s̲ that appears underlined in any context supporting Unicode.

Combining characters are diacritical marks in Unicode that modify the appearance of the base character they follow. The combining low line specifically draws a horizontal line below each character, simulating underlined text. This technique allows underlined text to appear in plain text environments where HTML or rich text formatting isn't available.

Tool description

This underline text converter adds Unicode combining underline characters to your text, creating underlined text that works anywhere. Each letter receives its own underline mark, making the text appear underlined when displayed. The tool can also remove combining underlines to restore normal text.

Examples

Input Output
Hello World H̲e̲l̲l̲o̲ W̲o̲r̲l̲d̲
Important I̲m̲p̲o̲r̲t̲a̲n̲t̲
Click Here C̲l̲i̲c̲k̲ H̲e̲r̲e̲
NEW N̲E̲W̲
Sale! S̲a̲l̲e̲!̲

Features

  • Adds combining underline to all non-whitespace characters
  • Works universally across platforms supporting Unicode
  • Bidirectional conversion (add or remove underlines)
  • Preserves spaces without underlining them for natural appearance
  • Real-time instant conversion

Use cases

  • Social media emphasis: Draw attention to key words or phrases in posts, comments, and profiles where underline formatting isn't normally available.
  • Plain text documents: Add visual emphasis in README files, code comments, or terminal outputs where rich formatting is unavailable.
  • Messaging apps: Highlight important information in chats and messages on platforms without built-in underline support.

How it works

The converter processes your text character by character. For each non-whitespace character, it appends the Unicode combining low line character (U+0332) immediately after it. This combining character doesn't take up its own space but instead renders as an underline beneath the preceding character. When removing underlines, the tool strips all combining low line characters from the text.

Limitations

  • Rendering quality depends on the font being used; some fonts display combining underlines better than others
  • The underline may appear segmented rather than continuous due to character spacing
  • Very old systems or limited Unicode fonts may not display the combining character correctly
  • Some applications may count each combining character as a separate character for length limits