What 𝟭 means
Its style distinguishes mathematical symbols while the digit stays one.
Mathematical writing used type styles to distinguish symbols before Unicode. Unicode’s 1999 proposal encoded these styled sets, including digits, so the distinctions could travel in plain text. The surrounding formula tells you what role this particular 1 has.
Part of the collection
Don't confuse it with
2
Related characters
3
Digit One
Unicode’s compatibility mapping connects 𝟭 to this ordinary digit. NFKC, a compatibility-normalization form, maps it to 1 and removes the style.
𝟣
Mathematical Sans-Serif Digit One
The regular-weight mathematical sans-serif digit one. It has the same value as 𝟭, with a lighter style.
𝟏
Mathematical Bold Digit One
The mathematical bold digit one in a serif style. It shares 𝟭’s value and bold weight but has a different typeface style.
Questions people ask
1Why does 𝟭 show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
More like this
11
How to type or find 𝟭
- Search it as
- bold 1 · bold sans serif one · unicode bold number · fancy number 1
- Shows up in
- Anything that takes text · its shape is whatever your font draws
Windows (Word)
Windows
macOS
HTML
𝟭CSS
\1D7EDGNOME / GTK
In GNOME and GTK text fields (2026), press CtrlShiftU, enter 1D7ED in hexadecimal, then press Enter.
Codes and encoding1 code points
HTML decimal
𝟭
HTML hex
𝟭
CSS content
content: "\1D7ED";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%F0%9D%9F%AD
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.