HTML Entity for Subscript One (₁)

Beginner
⏱️ 4 min read
📚 Updated: Aug 2025
🎯 1 Code Example
Unicode U+2081
HTML Entity for subscript one (₁) tutorial illustration

What You'll Learn

How to display Subscript One (₁) in HTML using Unicode entity methods: hex, decimal, and a CSS escape. This character is widely used in chemical formulas, math variables (like x₁), and scientific notation.

The character is part of the Superscripts and Subscripts Unicode block and is referenced as U+2081.

⚡ Quick Reference — Subscript One (₁)

Unicode U+2081

Superscripts and Subscripts block

Hex Code ₁

Hexadecimal reference

HTML Code ₁

Decimal reference

Named Entity —

No named entity available

Reference Table
Name           Value
────────────   ──────────
Unicode        U+2081
Hex code       ₁
HTML code      ₁
Named entity   —
CSS code       \2081
1

Complete HTML Example

This example renders ₁ using the hex entity, decimal entity, and a CSS escape on a pseudo-element:

html
<!DOCTYPE html>
<html>
<head>
 <style>
  #point:after{
   content: "\2081";
  }
 </style>
</head>
<body>

<p>Subscript One using Hexa Decimal: &#x2081;</p>
<p>Subscript One using HTML Code: &#8321;</p>
<p id="point">Subscript One using CSS Entity: </p>

</body>
</html>
Try It Yourself

🌐 Browser Support

Subscript One (₁) and its numeric entities are supported in modern browsers (rendering can vary slightly by font):

Chrome 1+
Firefox 1+
Safari 1+
Edge 12+
Opera 4+
Android 4.4+
iOS Safari 1+

👀 Live Preview

See ₁ used in a few formula-style contexts:

Variable index x₁ = 10
Large glyph ₁
Inline in text Sequence terms: a₁, a₂, a₃
Semantic alternative x1 (using the <sub> tag)
With entities Hex: ₁ | Decimal: ₁

🧠 How It Works

1

Hexadecimal Code

&#x2081; uses the Unicode hexadecimal value 2081 to display ₁.

HTML markup
2

Decimal HTML Code

&#8321; uses the decimal Unicode value 8321 for the same character.

HTML markup
3

CSS Entity

\2081 is a CSS escape typically used in the content property of pseudo-elements.

CSS stylesheet
4

Semantic Option

If you want semantic subscript formatting (not a specific glyph), use <sub>1</sub> to render 1 as a subscript.

HTML semantics
=

Same visual result

The entity forms display ₁. Unicode U+2081 sits in the Superscripts and Subscripts block.

✅

Use Cases

Subscript One (₁) is commonly used in:

🧪 Chemical Formulas

Indices and notations in chemistry content.

📐 Mathematical Equations

Sequences and variables such as x₁ and a₁.

📚 Scientific Content

Indices, parameters, and notation in technical writing.

📝 Footnotes

Design-driven footnote/reference markers.

💻 Technical Documentation

Specs and docs that include indexed terms like v₁.

💡 Best Practices

Do

  • Use &#x2081; or &#8321; consistently across a page
  • Prefer <sub> when you want semantic formatting for arbitrary text
  • Verify font support for subscript digits on your target devices
  • Keep formulas readable by pairing notation with explanations where needed

Don’t

  • Assume there is a named entity for ₁ (there isn’t)
  • Mix CSS escapes into HTML content (use them in stylesheets only)
  • Overuse subscript glyphs when plain text is clearer
  • Forget to test line-height and spacing in dense formulas

Key Takeaways

1

₁ is Unicode U+2081

U+2081 &#x2081; &#8321;
2

Use CSS escape in stylesheets via content

\2081
3

There is no named HTML entity for ₁

4

Use <sub>1</sub> when you need semantic subscript formatting

❓ Frequently Asked Questions

Use &#x2081; (hex), &#8321; (decimal), or \2081 in CSS content. All render ₁.
U+2081 (hex 2081, decimal 8321) in the Superscripts and Subscripts block.
No. Use numeric references like &#x2081; or &#8321;.
Use ₁ when you need the specific Unicode glyph. Use <sub> for semantic subscript formatting that applies to any text.
Subscript glyphs are font-dependent. If your primary font lacks subscript digits, the browser may fall back to a different font with a different look.

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About the author

Mari Selvan M P
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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HTML Entity | 1 Roman HTML Entity | 1 Superscript