Double-struck italic small i (ⅈ) is the Unicode character at U+2148 in the Letterlike Symbols block. Official name: DOUBLE-STRUCK ITALIC SMALL I. It is used in mathematics for the imaginary unit in complex numbers.
Remember
Character ⅈ
Unicode U+2148
Named entity ⅈ
Hex entity ⅈ
Decimal ⅈ
CSS escape \2148
Not the same i · ⅇ (ⅇ) · ⅉ
Prefer ⅈ in HTML markup (also aliased as ⅈ). You can also type ⅈ in UTF-8, or use numeric forms when needed.
Double-struck italic small i rendered alone and in a simple complex-number use.
Examplea + bⅈ
Large glyphⅈ
Comparedⅈ i ⅇ ⅉ
With entitiesNamed: ⅈ | Hex: ⅈ | Decimal: ⅈ
Code
Complete HTML Example
One page that shows Double Struck Italic Small I with named, hex, decimal, CSS escape, and a typed character. Use View Output or open the live editor.
Named + Hex + Decimal + CSS + Typed
Five ways to produce ⅈ, plus a simple complex-number example.
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Double Struck Italic Small I (ⅈ) in HTML</title>
<style>
#point::after {
content: "\2148";
}
</style>
</head>
<body>
<p>Small i using Named Entity: ⅈ</p>
<p>Small i using Hex Code: ⅈ</p>
<p>Small i using HTML Code: ⅈ</p>
<p id="point">Small i using CSS Entity: </p>
<p>Typed directly: ⅈ</p>
<p>Complex: a + bⅈ</p>
</body>
</html>
Small i using Named Entity: ⅈ
Small i using Hex Code: ⅈ
Small i using HTML Code: ⅈ
Small i using CSS Entity: ⅈ
Typed directly: ⅈ
Complex: a + bⅈ
How It Works
1. Named:ⅈ is the HTML5 name for U+2148 → ⅈ. Best default in markup (also ⅈ).
2. Hex:U+2148 → ⅈ in HTML. Same glyph as the named form.
3. Decimal: same code point as 8520 → ⅈ. Same result as hex and named.
4. CSS: use \2148 in content (not an HTML entity). #point::after appends that ⅈ after the paragraph text.
5. Typed / uses: paste ⅈ in UTF-8, or write a + bⅈ for a simple complex-number example.
Pitfalls & Tips
Common mistakes when working with Double Struck Italic Small I.
i
Not a styled letter i
Italic or bold CSS on ordinary i (U+0069) is not the same code point as ⅈ. Use the Letterlike Symbol when you need the imaginary-unit glyph.
II
No &II;
There is no capital &II; for U+2148. Use ⅈ (lowercase) or the ⅈ alias.
Alias
Longer name works too
ⅈ is an HTML5 alias for the same character as ⅈ. Prefer the short form in everyday markup.
Family
Related Letterlike forms
Pair with ⅇ (Euler / exponential) and ⅆ (differential) when writing math that uses the same double-struck italic set.
CSS vs HTML
Do not mix escapes
\2148 belongs in CSS strings. ⅈ / ⅈ / ⅈ belong in HTML.
Fonts
Math font coverage
Some fonts omit Letterlike Symbols. Prefer a math-capable font for reliable display of ⅈ.
Semicolon
End named entities
Always finish with ; — write ⅈ, not &ii.
Compatibility
Browser Support
Double-struck italic small i (U+2148) and its entity forms (ⅈ, ⅈ, ⅈ, CSS \\2148) are supported in all mainstream browsers. Visible glyphs depend on math / Letterlike Symbols font coverage.
✓ Universal support
Double Struck Italic Small I (ⅈ)
Encode with named, hex, decimal, CSS escape, or type the character — same code point everywhere encoding is supported.
100%Browser coverage
Google ChromeSupported
Yes
Microsoft EdgeSupported
Yes
Mozilla FirefoxSupported
Yes
Apple SafariSupported
Yes
OperaSupported
Yes
Internet ExplorerAll versions
Yes
U+2148 / entitiesFull support
Bottom line: Prefer ⅈ in HTML. Use ⅈ / ⅈ when numeric form is required, and \\2148 only inside CSS content.
Remember
Key Takeaways
Unicode: double-struck italic small i is U+2148 (decimal 8520) — glyph ⅈ.
HTML: prefer ⅈ — also ⅈ / ⅈ / type ⅈ.
CSS: use \2148 inside content for generated text.
Meaning:ⅈ = imaginary unit i — not a styled letter i.
Use ⅈ (named), ⅈ (hex), ⅈ (decimal), type ⅈ directly in UTF-8, or the CSS escape \2148 in content. Prefer ⅈ in normal HTML.
U+2148 (DOUBLE-STRUCK ITALIC SMALL I). Hex 2148, decimal 8520. It belongs to the Letterlike Symbols block (U+2100–U+214F).
Yes. Use ⅈ (or the alias ⅈ). Numeric forms ⅈ and ⅈ also work. There is no &II; for this character.
Use it in mathematical or scientific text when you need the double-struck italic i for the imaginary unit. Prefer an ordinary letter i when you only need a styled Latin i.
HTML entities (ⅈ, ⅈ, or ⅈ) go in markup. The CSS escape \2148 goes in stylesheet strings (usually content on ::before/::after).
No. ⅈ is ⅈ (U+2148). A styled CSS italic i is still the ordinary letter U+0069 — not this Letterlike Symbol.
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Did you know?
Double-struck italic small i is Unicode U+2148 (decimal 8520) — glyph ⅈ in the Letterlike Symbols block. HTML5 names it ⅈ (also ⅈ). Common use: the imaginary unit in complex numbers (e.g. a + bⅈ). Related: ⅇ (U+2147), ⅆ (U+2146).
