What 𝐣 means
It marks a variable; its exact role depends on the notation.
For a math j, follow the equation. In physics and engineering, bold letters can mark vectors—quantities with magnitude and direction—but other writers use bold for different distinctions.
By 1999, scientific publishers already used distinct mathematical letter styles. A Unicode proposal sought separate codes so plain-text formulas could preserve the difference between plain and bold variables.
Part of the collection
Don't confuse it with
3
Cyrillic Small Letter Je
Looks like j in most fonts; a classic homoglyph used to spoof Latin words in addresses.
Latin Small Letter Dotless J
Latin dotless j. Shows as j without its dot; easy to confuse in fonts and copied text.
ｊ
Fullwidth Latin Small Letter J
Same letter at CJK width; wider and upright, but can pass for j in names.
Related characters
1
Questions people ask
1Can 𝐣 turn into plain j?
Yes. Unicode’s compatibility forms, NFKC and NFKD, convert 𝐣 to plain j; that can erase a distinction used in a formula.
More like this
12
How to type or find 𝐣
- Search it as
- bold j · math j · unicode bold j · fancy j
- Shows up in
- Anything that takes text · its shape is whatever your font draws
Windows (Word)
Windows
HTML
𝐣CSS
\1D423Microsoft Word
Type
1D423 and press Alt+X. If it follows other hexadecimal text, select only the code first.Codes and encoding1 code points
HTML decimal
𝐣
HTML hex
𝐣
CSS content
content: "\1D423";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%F0%9D%90%A3
1
On screen
1
Code points
2
JS .length
4
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.