How to type Number Sign
# is Shift + 3 on a US keyboard and the key left of Enter on a UK one. Press Shift + 3 on a UK keyboard and you get £ instead, which is the whole of why the key looks wrong: nothing is broken and the layout is simply the other one. Alt + 35 on the numeric keypad produces it on any Windows layout, which is the way in when the keyboard in front of you has no key for it, and # writes it in HTML. Its codepoint is U+0023.
Number Sign
- Copy it
- Unicode
- U+0023
- Windows
- Alt + 35
| Where | Shortcut | How |
|---|---|---|
| Windows | Alt + 35 | Hold Alt and type the number on the numeric keypad. |
| HTML | # | Paste this into HTML source. |
| Unicode | U+0023 | NUMBER SIGN |
Symbols related to Number Sign
The Unicode code chart points from # to № and ♯.
Other symbols
Number Sign is not the only name it goes by. People look for # as hash and hashtag as well, and the search box on this site matches any of them, so you do not have to know which name Unicode chose.
# lives in the Basic Latin block (U+0000-U+007F), the original ASCII set: the letters, digits and punctuation printed on a US keyboard. Within Unicode it is classified as Po, a punctuation mark. Its bidirectional class makes it a European number terminator, so it sits beside a number without breaking its direction.
What Number Sign is used for
In mathematical notation # is an ordinary symbol: it carries no special spacing and sits in an expression the way a letter does, standing for a thing rather than doing something to the things around it. That is the classification unicode-math gives it, and it is what decides how the symbol is set: $\mathoctothorpe$ in LaTeX, in maths mode rather than in a sentence.
Unicode publishes a second list of names for # in CLDR, the keywords its own search data offers rather than the formal name, and they are hash sign, hashtag and pound. Those words are what somebody looking for this character is liable to type when Number Sign is not the name they know it by, and the search on the symbol lists matches them as well as the Unicode name.
What Unicode says about Number Sign
The standard recognises # under other names as well: pound sign (weight), hashtag, hash, crosshatch, octothorpe. Those are a formal alias, not a nickname, which is why they turn up in other people's documentation for the same codepoint.
Unicode annotates # directly. Against U+0023 the code chart carries the note “For denoting musical sharp 266F is preferred”. That is the standard saying what the character is for, rather than an inference from its name.
The code chart points from # to Numero Sign, Music Sharp Sign, l b bar symbol (U+2114), viewdata square (U+2317) and equals sign and slanted parallel (U+29E3). These are the characters the standard thinks you might have meant instead, which makes them the ones worth checking when Number Sign looks nearly right but not quite.
How Number Sign behaves in software
# takes one column in a terminal. It carries no direction of its own, so in a line that mixes English with Arabic or Hebrew it takes the direction of the text around it rather than forcing one.
What people ask about Number Sign
How to type number sign on keyboard?
Shift + 3 on a US keyboard, the key left of Enter on a UK one. Alt + 35 on the numeric keypad works on either.
Every way to write Number Sign
| Form | Value |
|---|---|
| Codepoint | U+0023 |
| Decimal | 35 |
| UTF-8 bytes | 23 |
| UTF-16 bytes | 00 23 |
| HTML entity | # |
| HTML numeric | # or # |
| CSS | \0023 |
| JavaScript | \u0023 |
| Python | \u0023 |
| URL-encoded | %23 |
| LaTeX, in prose | \# |
| LaTeX, in maths mode | $\mathoctothorpe$ |
| SVG | 0023.svg · (SIL Open Font License) |
If # needs escaping
# is one byte in ASCII, in UTF-8 and in every code page in common use, so it never arrives corrupted. Its problem is the opposite one: it means something to the software reading it. In HTML it can be written #, in a URL it is %23, and inside a CSV field, a shell command or a regular expression it has to be quoted or escaped rather than typed plainly. That is also why # is the character people substitute when the one they wanted will not type.