HTML Entity for Up Tack (⊥)
What You'll Learn
How to display the Up Tack (⊥) in HTML using hexadecimal, decimal, and CSS escape methods. This character is U+22A5 (UP TACK) in the Mathematical Operators block (U+2200–U+22FF)—also called the perpendicular symbol or falsum (logical bottom).
Render it with ⊥, ⊥, or CSS escape \22A5. There is no named HTML entity. Do not confuse ⊥ with the Down Tack (⊤, top/tautology) or Up Tack Below (combining mark U+031D).
⚡ Quick Reference — Up Tack
U+22A5Mathematical Operators
⊥Hexadecimal reference
⊥Decimal reference
—Use numeric codes only
Name Value
──────────── ──────────
Unicode U+22A5
Hex code ⊥
HTML code ⊥
Named entity (none)
CSS code \22A5
Official name UP TACK
Also known as Perpendicular symbol, falsum (bottom)
Related U+22A4 = Down tack (⊤, top/tautology)
Block Mathematical Operators (U+2200–U+22FF)Complete HTML Example
A simple example showing ⊥ with hex, decimal, and a CSS content escape (no named entity):
<!DOCTYPE html>
<html>
<head>
<style>
#point::after{
content: "\22A5";
}
</style>
</head>
<body>
<p>Up Tack (hex): ⊥</p>
<p>Up Tack (decimal): ⊥</p>
<p id="point">Up Tack (CSS): </p>
</body>
</html>🌐 Browser Support
U+22A5 is universally supported in modern browsers when rendered with a font that includes Mathematical Operators:
👀 Live Preview
See the Up Tack (⊥) rendered live in different contexts:
🧠 How It Works
Hexadecimal Code
⊥ uses the Unicode hexadecimal value 22A5 to display the Up Tack. The x prefix indicates hexadecimal format.
Decimal HTML Code
⊥ uses the decimal Unicode value 8869 to display the same character.
CSS Entity
\22A5 is used in CSS stylesheets, particularly in the content property of pseudo-elements like ::before and ::after.
Same visual result
All three methods produce the glyph: ⊥. Unicode U+22A5 in the Mathematical Operators block (U+2200–U+22FF). No named entity.
Use Cases
The Up Tack (⊥) commonly appears in:
Equations and formulas using the perpendicular symbol.
Falsum (bottom) in formal logic and proof systems.
Proofs, lattice theory, and theoretical mathematics.
Perpendicular lines and right-angle notation (e.g. AB ⊥ CD).
Academic papers, research, and scholarly content.
Formal methods, type theory, and programming language semantics.
Textbooks, lecture notes, and interactive math tutorials.
💡 Best Practices
Do
- Use
⊥or⊥for math and logic markup - Pick one numeric style (hex or decimal) per project
- Add
aria-labelfor standalone symbols in accessibility contexts - Pair ⊥ with plain text on first use (e.g. “perpendicular” or “falsum”)
- Test rendering across browsers and fonts that support math symbols
Don’t
- Confuse ⊥ (up tack / bottom) with ⊤ (down tack / top)
- Put CSS escape
\22A5in HTML text nodes - Assume every font renders ⊥ clearly at small sizes
- Expect a named HTML entity for U+22A5—use numeric references
- Use HTML entities in JavaScript (use
\u22A5instead)
Key Takeaways
Three ways to render ⊥ in HTML and CSS
⊥ ⊥For CSS stylesheets, use the escape in the content property
\22A5Unicode U+22A5 — UP TACK (perpendicular / falsum)
No named entity—use numeric references or CSS escape
Not the same as ⊤ (down tack / top / tautology)
❓ Frequently Asked Questions
⊥ (hex), ⊥ (decimal), or \22A5 in CSS content. There is no named HTML entity. All three produce ⊥.U+22A5 (UP TACK). Mathematical Operators block (U+2200–U+22FF). Hex 22A5, decimal 8869. Also called the perpendicular or falsum symbol.⊥ or ⊥) go directly in markup. The CSS escape \22A5 is used in stylesheets, typically in the content property of pseudo-elements. Same visual result, different layers of the stack.⊥ or ⊥ in HTML, or CSS escape \22A5 in stylesheets.Explore More HTML Entities!
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