HTML Entity for Combining Double Low Line (U+0333)
Beginner
5 min read
Updated: Sep 2026
1 example
Unicode U+0333
Definition
What Is Combining Double Low Line?
Combining double low line (U+0333) is a combining mark in the Combining Diacritical Marks block. It does not stand alone like a normal letter — it draws a double line under the character that comes before it. Example: a + ̳ renders as a̳.
Remember
Character combining double low line (after a base)
Unicode U+0333
Hex entity ̳
Decimal ̳
CSS escape \0333
Named entity (none for U+0333)
Example a̳ → a̳
Not the same _ U+005F · single low line U+0332
Use U+0333 when you need a double underline attached to a specific character. For everyday UI underlines on whole words or links, prefer CSS text-decoration: underline instead.
Double low line using Hex Code: a̳
Double low line using HTML Code: a̳
Double low line using CSS Entity: a̳
Typed directly: a̳
How It Works
1. Hex: write the base letter, then ̳ → a̳ becomes a̳.
2. Decimal: same mark as 819 → a̳. Same result as hex.
3. CSS: put base + escape in one string: content: "a\0333". #point::after appends that sequence after the paragraph text.
4. Typed: in UTF-8 you can type a then the combining double low line. Order must stay base first, mark second.
Pitfalls & Tips
Common mistakes when working with combining double low line.
Order
Base letter first
Write a̳, never put U+0333 before the letter you want to underline.
Named?
No named entity for U+0333
Use numeric forms. The ASCII underscore _ is a different character (U+005F).
UI
Prefer CSS for links
For underlining whole words or interactive text, use CSS text-decoration — combining marks are for character-level typography.
CSS vs HTML
Do not mix escapes
\0333 belongs in CSS strings. ̳ / ̳ belong in HTML.
Fonts
Combining support varies
Some fonts stack poorly under the base. If layout looks wrong, try a font with strong diacritic support.
Semicolon
End references
Always finish with ; — write ̳, not ̳.
Compatibility
Browser Support
Combining double low line (U+0333) and its numeric entity forms (̳, ̳, CSS \\0333) are supported in all mainstream browsers. Stacking quality depends on font support for combining marks.
✓ Universal support
Combining Double Low Line (U+0333)
Encode with hex, decimal, or CSS escape after a base letter — same combining mark everywhere encoding is supported.
100%Browser coverage
Google ChromeSupported
Yes
Microsoft EdgeSupported
Yes
Mozilla FirefoxSupported
Yes
Apple SafariSupported
Yes
OperaSupported
Yes
Internet ExplorerAll versions
Yes
U+0333 / entitiesFull support
Bottom line: Use ̳ or ̳ after a base letter when you need a double combining underline, and \\0333 only inside CSS content strings. Prefer CSS text-decoration for everyday UI underlines.
Remember
Key Takeaways
Unicode: combining double low line is U+0333 (decimal 819).
HTML: base first, then ̳ or ̳ (e.g. a̳).
CSS: use "a\0333" (or another base) inside content.
Default UI: prefer CSS underlines for links and words; use U+0333 for character-level marks.
One line:U+0333 → after a base letter as ̳ / ̳ / CSS \0333.
Frequently Asked Questions
Place ̳ (hex) or ̳ (decimal) immediately after a base letter — for example a̳. In CSS, use content: "a\0333". There is no named HTML entity for U+0333.
U+0333 (hex 0333, decimal 819). It belongs to the Combining Diacritical Marks block and draws a double low line under the preceding base character.
No. Use numeric references like ̳ or ̳. Do not confuse it with the ASCII underscore _ (U+005F) or combining single low line (U+0332).
Use it when you need a double underline attached to a specific character for typography or linguistic markup. For normal UI underlines, prefer CSS text-decoration: underline instead.
HTML entities (̳ or ̳) go in markup after the base letter. The CSS escape \0333 goes in stylesheet strings (usually content on ::before/::after), typically as "a\0333".
U+0333 is a combining double low line that attaches to the previous character. _ (U+005F) is a spacing underscore. U+0332 is a combining single low line. They are not interchangeable.
🤔
Did you know?
Combining double low line is Unicode U+0333 (decimal 819). It is a combining mark — place it after a base letter (e.g. a̳ → a̳). It draws a double line under the base. HTML5 has no named entity. It is not the ASCII low line _ (U+005F).
