HTML Entity for Lowercase Y Umlaut (ÿ)

Beginner

5 min read

Updated: Sep 2026

1 example

Unicode U+00FF

HTML Entity for lowercase y with diaeresis (U+00FF) tutorial illustration

Definition

What Is the Lowercase Y Umlaut Entity?

Lowercase y umlaut (ÿ) is the Latin-1 Supplement character at Unicode U+00FF (LATIN SMALL LETTER Y WITH DIAERESIS). It is the letter y with a diaeresis (¨) above — used in French place names, Dutch, Albanian, and other orthographies.

Remember

Character     ÿ
Unicode       U+00FF
Named entity  &yuml;
Hex entity    &#x00FF;
Decimal       &#255;
CSS escape    \00FF
Capital       &Yuml; (Ÿ)

Named, hex, decimal, CSS, and a typed character all produce the same glyph: ÿ. Prefer ÿ in HTML source for clarity.

Reference

Quick Reference

One table for every form you will actually use.

Form	Code	Where it goes
Named entity	`ÿ`	HTML markup (best default)
Hex entity	`ÿ`	HTML markup
Decimal entity	`ÿ`	HTML markup
CSS escape	`\00FF`	Stylesheet `content`
Direct character	`ÿ`	UTF-8 HTML text

When to Use Which

Situation	Use
Readable HTML source	`ÿ`
Numeric entity required	`ÿ` or `ÿ`
Generated text via `::before` / `::after`	`content: "\00FF"`
Capital Ÿ	`&Yuml;` — see Uppercase Y Diaeresis
Acute instead of diaeresis	See Lowercase Y Acute

See it

Live Preview

Lowercase y umlaut in French and comparison contexts.

French sample L'Haÿ-les-Roses, Aÿ-Champagne

Large glyph ÿ

Named entity ÿ → ÿ

vs y / Ÿ / ý ÿ | y | Ÿ | ý

With entities Named: ÿ | Hex: ÿ | Decimal: ÿ

Code

Complete HTML Example

One page that shows this character with named, hex, decimal, and CSS forms. Use View Output or open the live editor.

Named + Hex + Decimal + CSS

Four ways to produce ÿ in a single document.

html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Lowercase Y Umlaut (&yuml;)</title>
  <style>
    #point::after {
      content: "\00FF";
    }
  </style>
</head>
<body>
  <p>Using Named Entity: &yuml;</p>
  <p>Using Hex Code: &#x00FF;</p>
  <p>Using HTML Code: &#255;</p>
  <p id="point">Using CSS Entity: </p>
  <p lang="fr">Fran&ccedil;ais: L'Ha&yuml;-les-Roses</p>
</body>
</html>

Try It Yourself

How It Works

1. Named: ÿ is the clearest HTML form and renders ÿ.

2. Hex: U+00FF → ÿ in HTML. Same result as the named entity.

3. Decimal: same code point as 255 → ÿ. Same result as hex.

4. CSS: use \00FF in content (not an HTML entity). #point::after appends that ÿ after the paragraph text.

Pitfalls & Tips

Common mistakes when working with lowercase y umlaut.

Case

`ÿ` ≠ `&Yuml;`

Named entities are case-sensitive. Lowercase is ÿ; uppercase is Ÿ.

Look-alikes

Not ý or ŷ

Diaeresis (¨) is not acute (´) or circumflex (^). Do not confuse ÿ with ý or &ycirc;.

Compose

Prefer precomposed

Use ÿ instead of y plus combining diaeresis (U+0308) when the precomposed form exists.

CSS vs HTML

Do not mix escapes

\00FF belongs in CSS. ÿ / ÿ / ÿ belong in HTML.

Encoding

Declare UTF-8

If you type ÿ directly, keep <meta charset="UTF-8"> so the file is not misread.

Semicolon

End references

Always finish with ; — write ÿ, not &yuml.

Compatibility

Browser Support

Lowercase y umlaut (U+00FF) and its entity forms (ÿ, ÿ, ÿ, CSS \\00FF) are supported in all modern browsers.

✓ Universal encoding

Lowercase Y Umlaut (ÿ)

Encode with named, hex, decimal, or CSS escape — or type ÿ directly in UTF-8 HTML.

100% Browser coverage

Google Chrome Supported

Yes

Microsoft Edge Supported

Yes

Mozilla Firefox Supported

Yes

Apple Safari Supported

Yes

Opera Supported

Yes

Internet Explorer All versions

Yes

U+00FF Full support

Bottom line: Prefer ÿ for readable HTML. Use \\00FF only inside CSS content.

Remember

Key Takeaways

Unicode: this character is U+00FF (decimal 255).
HTML: prefer ÿ — or use ÿ / ÿ.
CSS: use \00FF inside content for generated text.
Watch out: ÿ ≠ &Yuml; ≠ ý.

One line: U+00FF → ÿ / ÿ / ÿ / CSS \00FF.

Frequently Asked Questions

How do I display lowercase y umlaut (ÿ) in HTML using entities?

Use ÿ (named), ÿ (hex), ÿ (decimal), or the CSS escape \00FF in the content property. All render ÿ. Prefer ÿ in HTML source.

What is the Unicode value for lowercase y umlaut?

U+00FF (LATIN SMALL LETTER Y WITH DIAERESIS). Hex 00FF, decimal 255. It belongs to the Latin-1 Supplement (U+0080–U+00FF).

Is there a named HTML entity for U+00FF?

Yes. ÿ is the HTML5 named entity for ÿ. The capital form is &Yuml; (Ÿ, U+0178) — names are case-sensitive.

When should I use this HTML entity?

Use it for French place names (e.g. L'Haÿ-les-Roses), Dutch, Albanian, or other text that needs ÿ, multilingual sites, and internationalized pages.

What is the difference between HTML code and CSS entity for U+00FF?

HTML entities (ÿ, ÿ, or ÿ) go in markup. The CSS escape \00FF is used in stylesheets (usually in the content property of ::before/::after). Both render ÿ.

Is ÿ the same as y acute (ý)?

No. Y umlaut ÿ is ÿ (diaeresis). Y acute ý is ý. They are different characters with different Unicode values.

Did you know?

Lowercase y umlaut (diaeresis) is Unicode U+00FF (decimal 255) — LATIN SMALL LETTER Y WITH DIAERESIS in the Latin-1 Supplement. HTML5 provides ÿ — the most readable form. Capital is &Yuml; (Ÿ, U+0178). Appears in French place names such as L'Haÿ-les-Roses and Aÿ-Champagne.

Next: Lowercase Yogh

Learn the HTML entity for ȝ (yogh) — next in this sequence.

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.

AWS Certified Developer – Associate (Credly)

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