HTML Entity for Contour Integral (∮)
What You'll Learn
How to display the Contour Integral (∮) in HTML using numeric references, the named entity, and CSS escapes. This character is U+222E (CONTOUR INTEGRAL) in the Mathematical Operators block (U+2200–U+22FF). It denotes a line integral along a closed curve, widely used in calculus, complex analysis, and physics.
You can use the named entity ∮, hex ∮, decimal ∮, or CSS \222E. ∮ is the most readable option when writing HTML by hand. Do not confuse ∮ with Integral U+222B (∫) or Clockwise Integral U+2231 (∱, ∱).
⚡ Quick Reference — Contour Integral
U+222EMathematical Operators (U+2200–U+22FF)
∮Hexadecimal reference
∮Decimal reference
∮Standard HTML entity
Name Value
──────────── ──────────
Unicode U+222E
Hex code ∮
HTML code ∮
Named entity ∮
CSS code \222EComplete HTML Example
This example demonstrates the Contour Integral (∮) using hexadecimal code, decimal HTML code, the named entity ∮, and a CSS content escape:
<!DOCTYPE html>
<html>
<head>
<style>
#point:after{
content: "\222E";
}
</style>
</head>
<body>
<p>Contour Integral using Hexa Decimal: ∮</p>
<p>Contour Integral using HTML Code: ∮</p>
<p>Contour Integral using HTML Entity: ∮</p>
<p id="point">Contour Integral using CSS Entity: </p>
</body>
</html>🌐 Browser Support
U+222E is supported in modern browsers; math fonts improve glyph quality:
👀 Live Preview
See the Contour Integral in mathematical contexts:
🧠 How It Works
Hexadecimal Code
∮ references code point U+222E using hex digits 222E.
Decimal HTML Code
∮ is the decimal equivalent (8750) for the same character.
Named HTML Entity
∮ is the standard named entity for U+222E—“con” for contour plus “int” for integral.
CSS Entity
\222E is the CSS escape for U+222E, used in the content property of ::before or ::after.
Same visual result
All four methods produce the Contour Integral glyph: ∮. Unicode U+222E sits in Mathematical Operators (U+2200–U+22FF).
Use Cases
The Contour Integral (∮) commonly appears in:
Contour integrals, line integrals, and advanced calculus notation in equations.
Integrals in physics formulae, electromagnetism, and engineering documentation.
Published papers, textbooks, and educational content with integral notation.
Technical documentation and research articles with mathematical expressions.
Equation editors, math input fields, and formula displays on the web.
Unicode tables and Mathematical Operators glossaries.
Pair with MathML or alt text (e.g. “contour integral”) for screen readers.
💡 Best Practices
Do
- Prefer
∮for readable HTML when writing equations by hand - Use math-oriented fonts (Cambria Math, STIX, Noto Sans Math) for clearer glyphs
- Keep entity style consistent within a document
- Use
\222Eonly inside CSScontent, not in HTML text nodes - Consider MathML or KaTeX/MathJax for complex multi-line equations
Don’t
- Confuse U+222E (∮) with U+2231 clockwise integral (∱) or U+222B standard integral (
∫) - Use U+0222E notation—the correct code point is U+222E
- Assume every integral symbol is interchangeable—each has distinct Unicode semantics
- Rely on default fonts alone for publication-quality math rendering
- Mix entity styles randomly in one file
Key Takeaways
Named entity is the easiest option
∮Numeric references also render ∮
∮ ∮For CSS stylesheets, use the escape in the content property
\222EU+222E CONTOUR INTEGRAL
Four methods, one glyph — widely supported in modern browsers
❓ Frequently Asked Questions
∮ (named entity), ∮ (hex), ∮ (decimal), or \222E in CSS content. All produce ∮.U+222E (CONTOUR INTEGRAL). Mathematical Operators (U+2200–U+22FF). Hex 222E, decimal 8750.∮, ∮, or ∮) go directly in markup. The CSS escape \222E is used in stylesheets, typically in the content property of pseudo-elements.∮ is the named entity for U+222E. Clockwise Integral is a different character: U+2231 (∱, ∱).Explore More HTML Entities!
Discover 1500+ HTML character references — math operators, symbols, arrows, and more.
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