HTML Entity for Uppercase Y Diaeresis (Ÿ)

Beginner

5 min read

Updated: Sep 2026

1 example

Unicode U+0178

HTML Entity for uppercase Y diaeresis (U+0178) tutorial illustration

Definition

What Is Uppercase Y Diaeresis?

Uppercase Y diaeresis (Ÿ) is the Unicode character at U+0178 in Latin Extended-A. Official name: LATIN CAPITAL LETTER Y WITH DIAERESIS — a capital Y with two dots above (diaeresis/umlaut), used in French names and a few other orthographies.

Remember

Character     Ÿ
Unicode       U+0178
Named entity  &Yuml;  (capital Y)
Hex entity    &#x178;
Decimal       &#376;
CSS escape    \0178
Not the same  ÿ · Ŷ · Y

Prefer &Yuml; in HTML markup — the capital Y in the name matters. Numeric forms and typing Ÿ in UTF-8 also work. For the lowercase letter, use ÿ (ÿ, U+00FF).

Reference

Quick Reference

One table for every form you will actually use.

Form	Code	Where it goes
Named entity	`&Yuml;`	HTML markup (preferred)
Direct character	`Ÿ`	HTML text (UTF-8)
Hex entity	`Ÿ`	HTML markup
Decimal entity	`Ÿ`	HTML markup
CSS escape	`\0178`	Stylesheet `content`
Lowercase (related)	ÿ (U+00FF)	Named `ÿ`

When to Use Which

Situation	Use
Capital Y with diaeresis (Ÿ)	`&Yuml;` or type `Ÿ`
Lowercase y with diaeresis (ÿ)	ÿ (`ÿ`)
Capital Y with circumflex (Ŷ)	Ŷ (`&Ycirc;`)
Capital Y with acute (Ý)	Ý (`Ý`)
Plain capital Y	Y (U+0059)
Generated text via `::before` / `::after`	`content: "\0178"`

See it

Live Preview

Uppercase Y diaeresis rendered alone and next to related letters.

Large glyph Ÿ

Notation L'HAŸ

Compared Ÿ | ÿ | Ŷ

Hint Compare: Diaeresis Ÿ | Lower ÿ | Circumflex Ŷ | Acute Ý

With entities Named: Ÿ | Hex: Ÿ | Decimal: Ÿ

Code

Complete HTML Example

One page that shows the letter with named, hex, decimal, CSS escape, and a typed character. Use View Output or open the live editor.

Named + Hex + Decimal + CSS + Typed

Five ways to produce Ÿ, plus a short French-style sample.

html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Uppercase Y Diaeresis (Ÿ)</title>
  <style>
    #point::after {
      content: "\0178";
    }
  </style>
</head>
<body>
  <p>Using Named Entity: &Yuml;</p>
  <p>Using Hex Code: &#x178;</p>
  <p>Using HTML Code: &#376;</p>
  <p id="point">Using CSS Entity: </p>
  <p>Typed directly: Ÿ</p>
  <p lang="fr">Sample: L'HA&Yuml;</p>
</body>
</html>

Try It Yourself

How It Works

1. Named: &Yuml; (capital Y) is the clearest HTML form for U+0178. Lowercase ÿ is a different character (ÿ, U+00FF).

2. Hex: U+0178 → Ÿ in HTML. Same glyph as the named entity.

3. Decimal: same code point as 376 → Ÿ. Same glyph as hex and named.

4. CSS: use \0178 in content (not an HTML entity). #point::after appends that Ÿ after the paragraph text.

5. Typed / sample: paste Ÿ in UTF-8, or build French-style forms like L'HA&Yuml; with lang="fr".

Pitfalls & Tips

Common mistakes when working with U+0178.

Case

&Yuml; ≠ ÿ

&Yuml; → Ÿ (capital, U+0178). ÿ → ÿ (lowercase, U+00FF). Entity names are case-sensitive.

Blocks

Case pair spans two blocks

Capital Ÿ is Latin Extended-A (U+0178). Lowercase ÿ is Latin-1 (U+00FF). Both are valid — just different code points.

vs Ŷ

Not a circumflex

Ŷ (&Ycirc;) has a circumflex. Ÿ has two dots (diaeresis) — different marks.

Encoding

Keep UTF-8 declared

Extended Latin letters display reliably with <meta charset="UTF-8">. Prefer named entities when the source file encoding is uncertain.

CSS vs HTML

Do not mix escapes

\0178 belongs in CSS strings. &Yuml; / Ÿ / Ÿ belong in HTML.

A11y

Use real language context

When Ÿ appears in French names, keep surrounding text and lang accurate (for example fr) so screen readers get useful context.

Compatibility

Browser Support

Uppercase Y diaeresis (U+0178) and its entity forms (&Yuml;, Ÿ, Ÿ, CSS \\0178) are supported in all mainstream browsers. Latin Extended-A glyphs are widely available in system fonts.

✓ Universal support

Uppercase Y Diaeresis (Ÿ)

Encode with named, hex, decimal, CSS escape, or type the character — same code point everywhere encoding is supported.

100% Browser coverage

Google Chrome Supported

Yes

Microsoft Edge Supported

Yes

Mozilla Firefox Supported

Yes

Apple Safari Supported

Yes

Opera Supported

Yes

Internet Explorer IE 9+

Yes

U+0178 / &Yuml; Full support

Bottom line: Prefer &Yuml; (capital Y) in HTML. Use \\0178 only inside CSS content. Do not confuse with ÿ (ÿ), circumflex Ŷ, or acute Ý.

Remember

Key Takeaways

Unicode: uppercase Y diaeresis is U+0178 (decimal 376) — glyph Ÿ.
HTML: prefer &Yuml; (capital Y) — also Ÿ / Ÿ.
CSS: use \0178 inside content for generated text.
Meaning: Ÿ is capital diaeresis — not ÿ (ÿ), not Ŷ (circumflex), not plain Y.

One line: U+0178 → &Yuml; / Ÿ / Ÿ / CSS \0178.

Frequently Asked Questions

How do I display Ÿ in HTML?

Use &Yuml; (named), Ÿ (hex), Ÿ (decimal), type Ÿ directly in UTF-8, or the CSS escape \0178 in content. Prefer &Yuml; in normal HTML.

What is the Unicode value for uppercase Y diaeresis?

U+0178 (LATIN CAPITAL LETTER Y WITH DIAERESIS). Hex 178, decimal 376. It belongs to Latin Extended-A (U+0100–U+017F).

Is there a named HTML entity for U+0178?

Yes. Use &Yuml; (capital Y). Numeric forms Ÿ and Ÿ also work. Note: ÿ (lowercase) is a different letter (ÿ, U+00FF).

Is Ÿ the same as ÿ or Ŷ?

No. Ÿ is U+0178 (&Yuml;, capital diaeresis). ÿ is U+00FF (ÿ). Ŷ is U+0176 (&Ycirc;, circumflex).

When should I use &Yuml;?

Use it for French and other orthographies that need capital Ÿ — not as a substitute for Ŷ, Ý, or plain Y.

What is the difference between HTML code and CSS entity for U+0178?

HTML entities (&Yuml;, Ÿ, or Ÿ) go in markup. The CSS escape \0178 goes in stylesheet strings (usually content on ::before/::after).

Did you know?

Uppercase Y diaeresis is Unicode U+0178 (decimal 376) — glyph Ÿ in Latin Extended-A (U+0100–U+017F). HTML5 names it &Yuml; (capital Y). Official name: LATIN CAPITAL LETTER Y WITH DIAERESIS. Lowercase is ÿ (ÿ, U+00FF) in Latin-1 — the case pair spans two blocks. Used in French names such as L'Haÿ-les-Roses. Do not confuse with circumflex Ŷ (&Ycirc;) or acute Ý (Ý).

Next: Uppercase Y Hook

Learn the HTML entity for uppercase Y with hook (U+01B3).

Continue tutorial →

About the author

Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

Experience 12 years building web and cloud systems
Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

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