HTML Entity for Uppercase Z Double Struck Capital (ℤ)
What You'll Learn
How to display the uppercase Z double struck capital (ℤ) in HTML using named entity, hexadecimal, decimal, and CSS escape methods. This mathematical symbol denotes the set of integers, commonly written as ℤ in equations such as n ∈ ℤ or ℤ ⊂ ℝ. It is U+2124 in the Letterlike Symbols block (U+2100–U+214F).
Render it with ℤ, ℤ, ℤ, or CSS escape \2124. The named entity ℤ is often the most readable option in HTML source. Do not confuse ℤ (double-struck Z) with plain Z (U+005A) or accented letters like Ż (Z dot above). See also math entities.
⚡ Quick Reference — Uppercase Z Double Struck Capital Entity
U+2124Letterlike Symbols
ℤHexadecimal reference
ℤDecimal reference
ℤMost readable option
Name Value
──────────── ──────────
Unicode U+2124
Hex code ℤ
HTML code ℤ
Named entity ℤ
CSS code \2124
Meaning Double-struck capital Z (integers)
Also known as Blackboard bold Z
Related U+005A = plain Z; U+017B = Ż (Z dot above)
Block Letterlike Symbols (U+2100–U+214F)Complete HTML Example
A simple example showing the uppercase Z double struck capital (ℤ) using hexadecimal code, decimal HTML code, the named entity, and a CSS content escape:
<!DOCTYPE html>
<html>
<head>
<style>
#point:after{
content: "\2124";
}
</style>
</head>
<body>
<p>Symbol (hex): ℤ</p>
<p>Symbol (decimal): ℤ</p>
<p>Symbol (named): ℤ</p>
<p id="point">Symbol (CSS): </p>
</body>
</html>🌐 Browser Support
The uppercase Z double struck capital (ℤ) and the named entity ℤ are supported in all modern browsers:
👀 Live Preview
See the uppercase Z double struck capital (ℤ) in mathematical notation:
🧠 How It Works
Hexadecimal Code
ℤ uses the Unicode hexadecimal value 2124 to display the character. The x prefix indicates hexadecimal format.
Decimal HTML Code
ℤ uses the decimal Unicode value 8484 to display the same character. A common method for Letterlike Symbols.
Named Entity
ℤ is the standard named entity for ℤ—readable in source HTML and part of the HTML5 entity set for blackboard bold letters.
CSS Entity
\2124 is used in CSS stylesheets, particularly in the content property of pseudo-elements like ::before and ::after.
Same visual result
All four methods produce the glyph: ℤ. Unicode U+2124 sits in Letterlike Symbols. Do not confuse with plain Z (U+005A) or accented Z letters like Ż (U+017B). Use math-friendly fonts for best rendering.
Use Cases
The uppercase Z double struck capital (ℤ) is commonly used in:
Denote the set of integers ℤ in number theory, algebra, and discrete mathematics.
Textbooks, online courses, and tutorials explaining number systems and blackboard bold notation.
Research papers, theses, and journal articles in mathematics and computer science.
Equation editors, calculators, and interactive math apps that render set notation in HTML.
Technical documentation and formulas involving integer arithmetic, rings, and modular arithmetic.
API docs, developer guides, and content explaining mathematical concepts involving integer sets.
💡 Best Practices
Do
- Use
ℤin HTML when possible for readability - Serve pages as UTF-8; you can also type ℤ directly in UTF-8 source
- Use math-friendly fonts (e.g. Cambria Math, STIX Two Math) for clear double-struck rendering
- Use fonts that support Letterlike Symbols characters
- Distinguish ℤ (U+2124) from plain
Z(U+005A) and accented Z letters
Don’t
- Substitute plain
Zwhen ℤ is required for correct mathematical notation - Confuse ℤ (double-struck) with Ż (Z dot above—a Polish letter, not a math set)
- Put CSS escape
\2124in HTML text nodes - Assume all fonts render Letterlike Symbols identically
- Omit UTF-8 encoding on pages with mathematical symbols
Key Takeaways
Four references render ℤ; named entity is most readable
ℤ ℤ ℤFor CSS stylesheets, use the escape in the content property
\2124Unicode U+2124 — DOUBLE-STRUCK CAPITAL Z
Essential for integers, set theory, and mathematical content
Previous: Uppercase Z Dot Above (Ż) Next: Uppercase Z Hook
❓ Frequently Asked Questions
ℤ (named), ℤ (hex), ℤ (decimal), or \2124 in CSS content. The named entity ℤ is the most readable for HTML content.U+2124 (DOUBLE-STRUCK CAPITAL Z). Letterlike Symbols block. Hex 2124, decimal 8484. Commonly used to represent the set of integers.ℤ or ℤ) or the named entity ℤ is used in HTML content. The CSS entity (\2124) is used in CSS, e.g. in the content property of pseudo-elements. Both produce ℤ but in different contexts.Explore More HTML Entities!
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