HTML Entity for Planck Constant Over Two Pi (ℏ)

Beginner

5 min read

Updated: Sep 2026

1 example

Unicode U+210F

HTML Entity for Planck Constant Over Two Pi (U+210F) tutorial illustration

Definition

What Is the Planck Constant Over Two Pi Entity?

Planck Constant Over Two Pi is the letterlike symbol at Unicode U+210F for the reduced Planck constant (h-bar, ℏ). Prefer the named entity &planck; (also &hbar;), or use ℏ / ℏ.

Remember

Character     ℏ
Unicode       U+210F
Named entity  &planck;  (also &hbar;)
Hex entity    &#x210F;
Decimal       &#8463;
CSS escape    \210F

Hex, decimal, named, and CSS all produce the same h-bar. Do not confuse it with &planckh; (ℎ) or Latin h.

Reference

Quick Reference

One table for every form you will actually use.

Form	Code	Where it goes
Named entity	`&planck;`	HTML (preferred)
Alt named form	`&hbar;`	HTML5 synonym for U+210F
Hex entity	`ℏ`	HTML
Decimal entity	`ℏ`	HTML
CSS escape	`\210F`	Stylesheet `content`

When to Use Which

Situation	Use
Reduced Planck constant (h-bar) in HTML	`&planck;`
Need a numeric entity	`ℏ` or `ℏ`
Generated text via `::before` / `::after`	`content: "\210F"`
Planck’s constant h (not reduced)	See Planck Constant — `&planckh;`
Ordinary Latin letter h	Type `h` — not U+210F

See it

Live Preview

h-bar in physics context, compared with lookalikes.

Example E = ℏω

Large glyph ℏ

Named entity &planck; → ℏ

vs lookalikes ℏ | ℎ | h

With entities Hex: ℏ | Decimal: ℏ | Named: ℏ

Code

Complete HTML Example

One page that shows h-bar with hex, decimal, named, and CSS forms. Use View Output or open the live editor.

Hex + Decimal + Named + CSS

Four ways to render U+210F (h-bar ℏ).

html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Planck Constant Over Two Pi (U+210F)</title>
  <style>
    #point::after {
      content: "\210F";
    }
  </style>
</head>
<body>
  <p>Using Hex Code: &#x210F;</p>
  <p>Using HTML Code: &#8463;</p>
  <p>Using Named Entity: &planck;</p>
  <p>Formula: E = &planck;&omega;</p>
  <p id="point">Using CSS Entity: </p>
</body>
</html>

Try It Yourself

How It Works

1. Hex: ℏ inserts U+210F from its hex value → ℏ.

2. Decimal: same character as 8463 → ℏ. Same visual result.

3. Named: &planck; is the readable HTML5 name (also &hbar;).

4. CSS: use \210F only inside content (e.g. on ::after).

Pitfalls & Tips

Common mistakes when working with h-bar.

vs ℎ

Not `&planckh;`

&planckh; is U+210E (Planck’s constant h). h-bar is U+210F with &planck;.

Name

No trailing `h` on `&planck;`

&planck; = ℏ (U+210F). &planckh; = ℎ (U+210E). Easy to swap — check the trailing h.

Slug

URL says “modified”

The path /planck-constant-modified is a stable slug. Unicode name is PLANCK CONSTANT OVER TWO PI (h-bar).

A11y

Spell out on first use

In teaching content, write “reduced Planck constant (h-bar)” once before relying on ℏ alone.

CSS vs HTML

Do not mix escapes

\210F belongs in CSS. &planck; / ℏ belong in HTML.

Semicolon

End references

Always finish with ; — write &planck;, not &planck.

Compatibility

Browser Support

Planck Constant Over Two Pi (U+210F) and its entity forms (&planck;, &hbar;, ℏ, ℏ, CSS \\210F) are supported in all mainstream browsers.

✓ Universal support

Planck Constant Over Two Pi (ℏ)

Encode with named, hex, decimal, or CSS escape. Reduced constant (h-bar) — not Planck’s h.

100% Browser coverage

Google Chrome Supported

Yes

Microsoft Edge Supported

Yes

Mozilla Firefox Supported

Yes

Apple Safari Supported

Yes

Opera Supported

Yes

Internet Explorer IE 9+

Yes*

U+210F Full support

Bottom line: Prefer &planck; in HTML. Use \\210F only inside CSS content.

Remember

Key Takeaways

Unicode: h-bar is U+210F (decimal 8463).
HTML: prefer &planck; (also &hbar; / ℏ).
CSS: use \210F inside content.
Lookalike: not &planckh; (ℎ) or Latin h.

One line: U+210F → &planck; (also ℏ / ℏ / CSS \210F).

Frequently Asked Questions

How do I display h-bar in HTML using entities?

Use ℏ (hex), ℏ (decimal), &planck; (named; also &hbar;), or the CSS escape \210F in the content property. All render the reduced Planck constant ℏ.

What is the Unicode value for Planck Constant Over Two Pi?

U+210F (PLANCK CONSTANT OVER TWO PI). Hex 210F, decimal 8463. It belongs to the Letterlike Symbols block and is commonly called h-bar.

Is there a named HTML entity for U+210F?

Yes. Prefer &planck; for readable HTML. &hbar; is also defined in HTML5 for the same character.

When should I use this HTML entity?

Use it in quantum mechanics when you need the reduced Planck constant ℏ = h/(2π) — for example E = ℏω written as E = &planck;ω.

Is U+210F the same as Planck’s constant h (ℎ)?

No. U+210F (&planck;) is h-bar (ℏ). U+210E (&planckh;) is PLANCK CONSTANT (ℎ). Different characters for h vs h/(2π).

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

HTML entities (&planck;, ℏ, or ℏ) go in markup. The CSS escape \210F is used in stylesheets (usually in content on ::before/::after). Both render ℏ.

Did you know?

Planck Constant Over Two Pi (h-bar) is Unicode U+210F (decimal 8463) — in Letterlike Symbols. Prefer &planck; (also &hbar;), or use ℏ / ℏ. It is h/(2π). Do not confuse with &planckh; (ℎ, U+210E).

Next: Plus

Continue with the Plus (+) entity tutorial.

Plus 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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