Contour integral (∮) is the Unicode character at U+222E in the Mathematical Operators block. It is used in calculus and physics for an integral taken over a closed curve (contour) — not the same as the ordinary integral sign (∫).
Remember
Character ∮
Unicode U+222E
Hex entity ∮
Decimal ∮
Named entity ∮ / ∮ / ∮
CSS escape \222E
Not the same ∫ U+222B · ∲ U+2232
All of these produce the same glyph: ∮. Prefer ∮ or a typed ∮ in hand-written HTML; use numeric forms when generating markup.
Contour integral rendered in common math contexts.
Inline math∮f(z) dz
Large glyph∮
Compared∮ ∫ ∲
Monospace∮ C
With entitiesNamed: ∮ | Hex: ∮ | Decimal: ∮
Code
Complete HTML Example
One page that shows Contour Integral with the named entity, hex entity, decimal entity, CSS escape, and a typed character. Use View Output or open the live editor.
Named + Hex + Decimal + CSS + Typed
Five ways to produce ∮ in a single document.
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Contour Integral (∮) in HTML</title>
<style>
#point::after {
content: "\222E";
}
</style>
</head>
<body>
<p>Contour integral using Named Entity: ∮</p>
<p>Contour integral using Hex Code: ∮</p>
<p>Contour integral using HTML Code: ∮</p>
<p id="point">Contour integral using CSS Entity: </p>
<p>Typed directly: ∮</p>
</body>
</html>
Contour integral using Named Entity: ∮
Contour integral using Hex Code: ∮
Contour integral using HTML Code: ∮
Contour integral using CSS Entity: ∮
Typed directly: ∮
How It Works
1. Named:∮ (aliases ∮, ∮) is the HTML5 named reference for U+222E → ∮.
2. Hex:U+222E → ∮ in HTML. Same glyph as the named form.
3. Decimal: same code point as 8750 → ∮. Same result as hex.
4. CSS: use \222E in content (not an HTML entity). #point::after appends that ∮ after the paragraph text.
5. Typed: in a UTF-8 page you can paste ∮ directly. All five lines show the same glyph.
Pitfalls & Tips
Common mistakes when working with Contour Integral.
Named
Several aliases
∮, ∮, and ∮ all produce ∮. Pick one and stay consistent.
∫ vs ∮
Not ordinary integral
∫ is U+222B (∫). Contour integral is U+222E (∮).
Direction
Clockwise variant exists
For clockwise contour integral use ∲ (∲), not plain ∮.
CSS vs HTML
Do not mix escapes
\222E belongs in CSS. ∮ / ∮ / ∮ belong in HTML.
Fonts
Math font coverage
Some fonts omit U+222E or render it poorly. Prefer a font with Mathematical Operators coverage.
Semicolon
End references
Always finish with ; — write ∮ and ∮, not bare forms.
Compatibility
Browser Support
Contour integral (U+222E) and its entity forms (∮, ∮, ∮, CSS \\222E) are supported in all mainstream browsers. Visible glyphs depend on font coverage.
✓ Universal support
Contour Integral (∮)
Encode with named, hex, decimal, CSS escape, or type the character — same glyph everywhere encoding is supported.
100%Browser coverage
Google ChromeSupported
Yes
Microsoft EdgeSupported
Yes
Mozilla FirefoxSupported
Yes
Apple SafariSupported
Yes
OperaSupported
Yes
Internet ExplorerAll versions
Yes
U+222E / entitiesFull support
Bottom line: Prefer ∮ or typed ∮ in HTML. Use \\222E only inside CSS content. Prefer ∫ for ordinary integrals.
Remember
Key Takeaways
Unicode: contour integral is U+222E (decimal 8750) — glyph ∮.
HTML: use ∮ (or aliases), ∮, ∮, or type ∮.
One line:U+222E → ∮ / ∮ / CSS \222E / type ∮.
Frequently Asked Questions
Use ∮ (hex), ∮ (decimal), ∮ / ∮ / ∮ (named), or the CSS escape \222E in the content property. All render ∮. You can also paste ∮ directly when your file is UTF-8.
U+222E (hex 222E, decimal 8750). It belongs to the Mathematical Operators block and represents a contour (closed-path) integral.
Yes. ∮, ∮, and ∮ are HTML5 named references for ∮. Numeric forms ∮ and ∮ also work.
Use it in math or physics pages for contour integrals. For a plain indefinite/definite integral symbol, prefer ∫ (U+222B / ∫).
HTML entities (∮, ∮, or ∮) go in markup. The CSS escape \222E goes in stylesheet strings (usually content on ::before/::after).
∮ (U+222E) is contour integral. ∫ (U+222B / ∫) is the ordinary integral. ∲ (U+2232 / ∲) is clockwise contour integral — a directed variant.
🤔
Did you know?
Contour integral is Unicode U+222E (decimal 8750) — glyph ∮ in the Mathematical Operators block. HTML named references are ∮, ∮, and ∮. It is used in calculus and physics for integrals over a closed curve. It is not the ordinary integral ∫ (U+222B / ∫).
