HTML Entity for Double Struck Italic Small D (ⅆ)

Beginner
⏱️ 5 min read
📚 Updated: Jun 2026
🎯 1 Code Example
Unicode U+2146
HTML entity for Double Struck Italic Small D (U+2146) tutorial illustration

What You'll Learn

How to display the Double Struck Italic Small D (ⅆ) in HTML using hexadecimal, decimal, the named entity ⅆ, and CSS escape methods. This character is U+2146 (DOUBLE-STRUCK ITALIC SMALL D) in the Letterlike Symbols block (U+2100–U+214F)—the double-struck italic form of Latin small letter d used in mathematics and differential notation.

Render it with ⅆ, ⅆ, ⅆ, or CSS escape \2146. For the capital variant use ⅅ (U+2145, ⅅ). See also math entities.

⚡ Quick Reference — Double Struck Italic Small D

Unicode U+2146

Letterlike Symbols block

Hex Code ⅆ

Hexadecimal reference

HTML Code ⅆ

Decimal reference

Named Entity ⅆ

HTML5 named entity for U+2146

Reference Table
Name           Value
────────────   ──────────
Unicode        U+2146
Hex code       ⅆ
HTML code      ⅆ
Named entity   ⅆ
CSS code       \2146
Related        U+2145 = Capital D (ⅅ)
1

Complete HTML Example

This example demonstrates the Double Struck Italic Small D (ⅆ) using hexadecimal code, decimal HTML code, the named entity ⅆ, and a CSS content escape:

html
<!DOCTYPE html>
<html>
<head>
 <style>
  #point:after{
   content: "\2146";
  }
 </style>
</head>
<body>
<p>Double Struck Italic Small D using Hexadecimal: &#x2146;</p>
<p>Double Struck Italic Small D using HTML Code: &#8518;</p>
<p>Double Struck Italic Small D using HTML Entity: &dd;</p>
<p id="point">Double Struck Italic Small D using CSS Entity: </p>
</body>
</html>
Try it Yourself

🌐 Browser Support

U+2146 is widely supported in modern browsers when rendered with a font that includes Letterlike Symbols:

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

👀 Live Preview

See the Double Struck Italic Small D (ⅆ) in mathematical notation:

Large glyph ⅆ
Capital vs small ⅅ capital   ⅆ small
Named entity &dd; → ⅆ
All HTML refs &#x2146; &#8518; &dd;
CSS escape \2146

🧠 How It Works

1

Hexadecimal Code

&#x2146; uses the Unicode hexadecimal value 2146 to display the Double Struck Italic Small D. The x prefix indicates hexadecimal format.

HTML markup
2

Decimal HTML Code

&#8518; uses the decimal Unicode value 8518 to display the same character.

HTML markup
3

Named HTML Entity

&dd; is the HTML5 named entity for U+2146. It is easy to read in source and resolves to the same character (ⅆ).

HTML markup
4

CSS Entity

\2146 is used in CSS stylesheets, particularly in the content property of pseudo-elements like ::before and ::after.

CSS stylesheet
=

Same visual result

All four methods produce: ⅆ. Unicode U+2146. Capital variant: &DD; (ⅅ, U+2145).

✅

Use Cases

The Double Struck Italic Small D (ⅆ) commonly appears in:

📐 Differential notation

Calculus where the double-struck italic small d appears in differentials (e.g. ⅆx alongside dx notation).

🔬 Set theory & domains

Domain notation and set theory where this letterlike symbol distinguishes from the regular letter D.

📚 Academic publishing

Textbooks, papers, and course materials requiring letterlike math symbols in HTML.

💻 Math on the web

Equation editors and math rendering alongside other double-struck italic letters.

📖 Unicode references

Entity lists and guides for Letterlike Symbols (U+2100–U+214F).

♿ Accessibility

Use math-capable fonts so ⅆ renders clearly for all readers.

💡 Best Practices

Do

  • Use &dd; for readable markup, or &#x2146; / &#8518;
  • Use math fonts (Cambria Math, STIX Two Math) for reliable rendering
  • Distinguish ⅆ (small) from ⅅ (&DD;, capital)
  • Use \2146 only inside CSS content
  • Keep entity style consistent across the document

Don’t

  • Confuse &dd; (U+2146) with unrelated entities
  • Use &DD; when you need capital ⅅ
  • Put CSS escape \2146 in HTML text nodes
  • Forget UTF-8 (<meta charset="utf-8">) on math pages
  • Assume every font includes Letterlike Symbols

Key Takeaways

1

Named entity available: &dd;

&#x2146; &#8518;
2

For CSS stylesheets, use the escape in the content property

\2146
3

Unicode U+2146 DOUBLE-STRUCK ITALIC SMALL D

4

Capital D: ⅅ via &DD; or &#x2145;

5

Four methods, one glyph — widely supported in modern browsers

❓ Frequently Asked Questions

Use &#x2146; (hex), &#8518; (decimal), &dd; (named entity), or \2146 in CSS content. All produce ⅆ.
U+2146 (DOUBLE-STRUCK ITALIC SMALL D). Letterlike Symbols block (U+2100–U+214F). Hex 2146, decimal 8518. Double-struck italic form of Latin small letter d.
When you need the double-struck italic small d in mathematical content: differential notation (e.g. ⅆx), expressions, or academic papers requiring this letterlike symbol.
HTML references (&#8518;, &#x2146;, or &dd;) go in markup. The CSS escape \2146 is used in stylesheets, typically in the content property of pseudo-elements.
&dd; is easier to read in source than &#8518; or &#x2146;, but all produce ⅆ. The named entity is part of the HTML5 entity set for Letterlike Symbols.

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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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