HTML Entity for Infinity (∞)

Beginner

6 min read

Updated: Sep 2026

1 example

Unicode U+221E

HTML Entity for Infinity (∞) tutorial illustration

Definition

What Is the Infinity Entity?

Infinity (∞) is the Mathematical Operators character at Unicode U+221E (INFINITY). Use it for unbounded quantities — limits (as x → ∞), infinite sets, and calculus.

Remember

Character     ∞
Unicode       U+221E
Hex entity    &#x221E;
Decimal       &#8734;
Named entity  &infin;
CSS escape    \221E

All of these produce the same glyph: ∞. Prefer ∞ in HTML source for clarity; use hex/decimal when generating entities, and CSS \221E only in content.

Reference

Quick Reference

One table for every form you will actually use.

Form	Code	Where it goes
Named entity	`∞`	HTML markup (best default)
Hex entity	`∞`	HTML markup
Decimal entity	`∞`	HTML markup
CSS escape	`\221E`	Stylesheet `content`
Direct character	`∞`	UTF-8 HTML text

When to Use Which

Situation	Use
Readable math HTML source	`∞`
Need a numeric entity in HTML	`∞` or `∞`
Generated text via `::before` / `::after`	`content: "\221E"`
UTF-8 page, typing is easy	Type `∞` directly
JavaScript numeric infinity	Use `Infinity` in code — not the HTML entity

See it

Live Preview

Infinity rendered in common math contexts.

Limit lim_x→∞ f(x)

Large glyph ∞

Set size |ℕ| = ∞

Named entity ∞ → ∞

With entities Hex: ∞ | Decimal: ∞ | Named: ∞

Code

Complete HTML Example

One page that shows Infinity with the hex entity, decimal entity, named entity, and CSS escape. Use View Output or open the live editor.

Hex + Decimal + Named + CSS

All four ways to produce ∞ in a single document.

html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Infinity (∞) in HTML</title>
  <style>
    #point::after {
      content: "\221E";
    }
  </style>
</head>
<body>
  <p>Infinity using Hex Code: &#x221E;</p>
  <p>Infinity using HTML Code: &#8734;</p>
  <p>Infinity using Named Entity: &infin;</p>
  <p id="point">Infinity using CSS Entity: </p>
</body>
</html>

Try It Yourself

How It Works

1. Hex: U+221E → ∞ in HTML. The browser turns it into ∞.

2. Decimal: same code point as 8734 → ∞. Same result as hex.

3. Named: ∞ is the HTML5 name for this character — easiest to read in source.

4. CSS: use \221E in content (not an HTML entity). #point::after appends that ∞ after the paragraph text.

Pitfalls & Tips

Common mistakes when working with the Infinity symbol.

Named

Prefer ∞

Named form is clearer than numeric codes in hand-written HTML.

CSS vs HTML

Do not mix escapes

\221E belongs in CSS. ∞ / ∞ / ∞ belong in HTML.

Display vs code

Not JS Infinity

∞ is for page text. In JavaScript use the numeric value Infinity.

Default

Type ∞ when you can

On UTF-8 pages you may type ∞ directly; entities help when encoding must be explicit.

Semicolon

End references

Always finish with ; — write ∞, not &infin.

Fonts

Math Operators support

Use fonts that include U+221E (most modern UI fonts do) so the glyph is not missing.

Compatibility

Browser Support

Infinity (U+221E) and its entity forms (∞, ∞, ∞, CSS \\221E) are supported in all mainstream browsers.

✓ Universal support

Infinity (∞)

Use ∞, or encode with hex, decimal, or CSS escape — same glyph everywhere.

100% Browser coverage

Google Chrome Supported

Yes

Microsoft Edge Supported

Yes

Mozilla Firefox Supported

Yes

Apple Safari Supported

Yes

Opera Supported

Yes

Internet Explorer All versions

Yes

U+221E / entities Full support

Bottom line: Prefer ∞ in HTML for readability. Use ∞ or ∞ when encoding must be numeric, and \\221E only inside CSS content.

Remember

Key Takeaways

Unicode: Infinity is U+221E (decimal 8734).
HTML: prefer ∞, or use ∞ / ∞.
CSS: use \221E inside content for generated text.
Use case: limits, infinite sets, and unbounded quantities in math text.

One line: U+221E → ∞ / ∞ / ∞ / CSS \221E.

Frequently Asked Questions

How do I display the Infinity symbol (∞) in HTML using entities?

Use ∞ (named), ∞ (hex), ∞ (decimal), or the CSS escape \221E in the content property. All render the Infinity symbol (∞).

What is the Unicode value for Infinity?

U+221E (INFINITY). Hex 221E, decimal 8734. It belongs to the Mathematical Operators block.

Is there a named HTML entity for Infinity?

Yes. ∞ is the named HTML5 entity for ∞ and is supported in all modern browsers.

When should I use the Infinity HTML entity?

Use it for limits (x → ∞), infinite sets, calculus, physics, and docs about unbounded values. Prefer ∞ for readable source, or numeric forms when generating markup.

What is the difference between HTML code and CSS entity for ∞?

HTML entities (∞, ∞, or ∞) go in markup. The CSS escape \221E is used in stylesheets (usually in the content property of ::before/::after). Both render ∞.

Is ∞ the same as Infinity in JavaScript?

No. ∞ is a Unicode math character for display. In JavaScript, Infinity is a numeric value (Number.POSITIVE_INFINITY) — unrelated to the HTML entity.

Did you know?

Infinity is Unicode U+221E (decimal 8734). HTML5 provides the named entity ∞ — prefer it for readable math markup, or use ∞ / ∞.

Next: Information Source

Learn the HTML entity for the Information Source symbol (ℹ) — next in this entity sequence.

Information Source tutorial →

About the author

Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

Experience 12 years building web and cloud systems
Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

AWS Certified Developer – Associate (Credly)

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