HTML Entity for Uppercase O Double Acute (Ő)

Beginner
⏱️ 5 min read
📚 Updated: Jun 2026
🎯 1 Code Example
Unicode U+0150
HTML Entity for Uppercase O Double Acute tutorial illustration

What You'll Learn

How to display the uppercase O with double acute (Ő) in HTML using named entity, hexadecimal, decimal, and CSS escape methods. This character is U+0150 in the Latin Extended-A block and is essential for correct Hungarian spelling.

Render it with Ő, Ő, Ő, or CSS escape \0150. The named entity Ő is often the most readable option in HTML source. Do not confuse Ő with Ó (acute) or Ö (diaeresis)—each is a distinct vowel in Hungarian.

⚡ Quick Reference — Uppercase O Double Acute Entity

Unicode U+0150

Latin Extended-A

Hex Code Ő

Hexadecimal reference

HTML Code Ő

Decimal reference

Named Entity Ő

Most readable option

Reference Table
Name           Value
────────────   ──────────
Unicode        U+0150
Hex code       Ő
HTML code      Ő
Named entity   Ő
CSS code       \0150
Meaning        Latin capital letter O with double acute
Related        U+0151 = ő (lowercase)
Block          Latin Extended-A (U+0100–U+017F)
1

Complete HTML Example

A simple example showing the uppercase O double acute (Ő) using hexadecimal code, decimal HTML code, the named entity, and a CSS content escape:

html
<!DOCTYPE html>
<html>
<head>
 <style>
  #point:after{
   content: "\0150";
  }
 </style>
</head>
<body>
<p>Symbol (hex): &#x150;</p>
<p>Symbol (decimal): &#336;</p>
<p>Symbol (named): &Odblac;</p>
<p id="point">Symbol (CSS): </p>
</body>
</html>
Try It Yourself

🌐 Browser Support

The uppercase O double acute (Ő) and the named entity &Odblac; are supported in all modern browsers:

Chrome1+
Firefox1+
Safari1+
Edge12+
Opera4+
Android4.4+
iOS Safari1+

👀 Live Preview

See the uppercase O double acute (Ő) in Hungarian contexts:

Large glyphŐ
HungarianŐr  |  Őz  |  Ő a legjobb
Named entity&Odblac; renders as Ő
Lowercaseő (U+0151) — use &odblac;
Not the same asÖ (diaeresis)  |  Ó (acute)  |  O (plain)
Numeric refs&#x150; &#336; &Odblac; \0150

🧠 How It Works

1

Named Entity

&Odblac; is the standard named entity for Ő—readable in source HTML and essential for correct Hungarian spelling.

HTML markup
2

Hexadecimal Code

&#x150; uses the Unicode hexadecimal value 150 to display the character. The x prefix indicates hexadecimal format.

HTML markup
3

Decimal HTML Code

&#336; uses the decimal Unicode value 336 to display the same character. A common method when a numeric reference is needed.

HTML markup
4

CSS Entity

\0150 is used in CSS stylesheets, particularly in the content property of pseudo-elements like ::before and ::after.

CSS stylesheet
=

Same visual result

All four methods produce the glyph: Ő. Unicode U+0150 sits in Latin Extended-A. Lowercase equivalent: U+0151 (ő, &odblac;). Do not confuse with Ö (diaeresis) or Ó (acute) in Hungarian.

✅

Use Cases

The uppercase O double acute (Ő) is commonly used in:

🇭🇺 Hungarian

Essential for capitalized words and proper names like Őr and Őz. The double acute is distinct from Ö and Ó in meaning and pronunciation.

📚 Dictionaries

Headwords, definitions, and pronunciation guides for Hungarian words beginning with Ő.

🌐 Language Learning

Hungarian lessons, flashcards, and vocabulary content with correct Ő spelling at sentence start.

⚙ Multilingual Sites

Hungarian localized websites, product names, place names, and user-generated content.

📝 Proper names

Personal names, surnames, and geographic names that require correct Ő at the start of a word or sentence.

🔍 Search & SEO

Correct rendering so users can find Hungarian content with proper accented spelling in search results.

💡 Best Practices

Do

  • Use &Odblac; in HTML when possible for readability
  • Serve pages as UTF-8; you can also type Ő directly in UTF-8 source
  • Set lang="hu" on Hungarian content for correct pronunciation
  • Use fonts that support Latin Extended-A characters
  • Distinguish Ő (double acute) from Ö (diaeresis) and Ó (acute)

Don’t

  • Substitute plain O, Ó, or Ö when Ő is required for correct Hungarian spelling
  • Confuse Ő (double acute) with Ö (diaeresis) or Ó (acute)
  • Put CSS escape \0150 in HTML text nodes
  • Assume Ő and ő are interchangeable—case matters in Hungarian
  • Omit UTF-8 encoding on pages with accented characters

Key Takeaways

1

Four references render Ő; named entity is most readable

&#x150; &#336; &Odblac;
2

For CSS stylesheets, use the escape in the content property

\0150
3

Unicode U+0150 — LATIN CAPITAL LETTER O WITH DOUBLE ACUTE

4

Lowercase pair is U+0151 (ő, &odblac;)

5

Previous: Uppercase O Dot Above (Ȯ)   Next: Uppercase O Double Grave

❓ Frequently Asked Questions

Use &Odblac; (named), &#x150; (hex), &#336; (decimal), or \0150 in CSS content. The named entity &Odblac; is the most readable for HTML content.
U+0150 (LATIN CAPITAL LETTER O WITH DOUBLE ACUTE). Latin Extended-A block. Hex 150, decimal 336. Essential for correct Hungarian spelling.
When writing Hungarian text at sentence start or in capitalized words and proper names (e.g. Őr, Őz), plus multilingual websites and language-learning content that require correct accented spelling.
Ő (double acute) is a distinct vowel from Ó (acute) and Ö (diaeresis). Each has a different pronunciation and meaning in Hungarian. Do not substitute one for another.
Yes. &Odblac; is part of the HTML5 entity set and is well supported in all modern browsers. Numeric codes remain a reliable alternative for older systems.

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About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
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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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