HTML Entity for Double Struck Italic Small I (ⅈ)

Beginner
⏱️ 5 min read
📚 Updated: Jun 2026
🎯 1 Code Example
Unicode U+2148
HTML entity for Double Struck Italic Small I (U+2148) tutorial illustration

What You'll Learn

How to display the Double Struck Italic Small I (ⅈ) in HTML using hexadecimal, decimal, the named entity ⅈ, and CSS escape methods. This character is U+2148 (DOUBLE-STRUCK ITALIC SMALL I) in the Letterlike Symbols block (U+2100–U+214F)—often used for the imaginary unit (i = √−1) in mathematics and complex numbers.

Render it with ⅈ, ⅈ, ⅈ, or CSS escape \2148. For small e use ⅇ (U+2147, ⅇ). See also math entities.

⚡ Quick Reference — Double Struck Italic Small I

Unicode U+2148

Letterlike Symbols block

Hex Code ⅈ

Hexadecimal reference

HTML Code ⅈ

Decimal reference

Named Entity ⅈ

HTML5 named entity for U+2148

Reference Table
Name           Value
────────────   ──────────
Unicode        U+2148
Hex code       ⅈ
HTML code      ⅈ
Named entity   ⅈ
CSS code       \2148
Related        U+2147 = Small e (ⅇ)
1

Complete HTML Example

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

html
<!DOCTYPE html>
<html>
<head>
 <style>
  #point:after{
   content: "\2148";
  }
 </style>
</head>
<body>
<p>Double Struck Italic Small I using Hexadecimal: &#x2148;</p>
<p>Double Struck Italic Small I using HTML Code: &#8520;</p>
<p>Double Struck Italic Small I using HTML Entity: &ii;</p>
<p id="point">Double Struck Italic Small I using CSS Entity: </p>
</body>
</html>
Try it Yourself

🌐 Browser Support

U+2148 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 I (ⅈ) in mathematical notation:

Large glyph ⅈ
Small e vs small i ⅇ e   ⅈ i
Named entity &ii; → ⅈ
All HTML refs &#x2148; &#8520; &ii;
CSS escape \2148

🧠 How It Works

1

Hexadecimal Code

&#x2148; uses the Unicode hexadecimal value 2148 to display the Double Struck Italic Small I. The x prefix indicates hexadecimal format.

HTML markup
2

Decimal HTML Code

&#8520; uses the decimal Unicode value 8520 to display the same character.

HTML markup
3

Named HTML Entity

&ii; is the HTML5 named entity for U+2148. It is easy to read in source and resolves to the same character (ⅈ).

HTML markup
4

CSS Entity

\2148 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: ⅈ. Unicode U+2148. Small e: &ee; (ⅇ, U+2147).

✅

Use Cases

The Double Struck Italic Small I (ⅈ) commonly appears in:

📐 Imaginary unit

Complex numbers where ⅈ denotes the imaginary unit (i = √−1), e.g. z = a + bⅈ.

🔬 Engineering & physics

Imaginary current or complex quantities in AC circuits, quantum mechanics, or wave equations.

📚 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 ⅈ renders clearly for all readers.

💡 Best Practices

Do

  • Use &ii; for readable markup, or &#x2148; / &#8520;
  • Use math fonts (Cambria Math, STIX Two Math) for reliable rendering
  • Distinguish ⅈ (i) from ⅇ (&ee;, small e)
  • Use \2148 only inside CSS content
  • Keep entity style consistent across the document

Don’t

  • Confuse &ii; (U+2148) with the regular letter i (U+0069)
  • Use &ee; when you need small i ⅈ
  • Put CSS escape \2148 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: &ii;

&#x2148; &#8520;
2

For CSS stylesheets, use the escape in the content property

\2148
3

Unicode U+2148 DOUBLE-STRUCK ITALIC SMALL I

4

Small e: ⅇ via &ee; or &#x2147;

5

Four methods, one glyph — widely supported in modern browsers

❓ Frequently Asked Questions

Use &#x2148; (hex), &#8520; (decimal), &ii; (named entity), or \2148 in CSS content. All produce ⅈ.
U+2148 (DOUBLE-STRUCK ITALIC SMALL I). Letterlike Symbols block (U+2100–U+214F). Hex 2148, decimal 8520. Double-struck italic form of Latin small letter i.
When you need the double-struck italic small i in mathematical content: complex numbers, imaginary unit, electrical engineering, quantum mechanics, expressions, or academic papers requiring this letterlike symbol.
HTML references (&#8520;, &#x2148;, or &ii;) go in markup. The CSS escape \2148 is used in stylesheets, typically in the content property of pseudo-elements.
&ii; is easier to read in source than &#8520; or &#x2148;, but all produce ⅈ. 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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Double Struck Italic Small E (ⅇ) Double Struck Italic Small J