How to type Double Up Arrow
To type Double Up Arrow (⇑), press Alt + 8657 on Windows, holding Alt while typing the digits on the numeric keypad, or write ⇑ in HTML. On any system you can copy it from this page, or enter its codepoint U+21D1 directly: Ctrl+Shift+U then 21d1 on Linux, or 21d1 then Alt+X in Microsoft Word.
Upwards Double Arrow
- Copy it
- Unicode
- U+21D1
- Windows
- Alt + 8657 needs regedit
| Where | Shortcut | How |
|---|---|---|
| Windows | Alt + 8657 | Above 255, so Windows will not accept it as typed. Copy the character instead. |
| Mac | N/A | Press the keys together. |
| HTML | ⇑ | Paste this into HTML source. |
| Unicode | U+21D1 | UPWARDS DOUBLE ARROW |
Symbols related to Double Up Arrow
These are filed under arrow in CLDR, the keyword list Unicode publishes alongside the names.
Other arrows symbols
⇑ lives in the Arrows block (U+2190-U+21FF), arrows in every direction and weight. Within Unicode it is classified as So, a symbol.
What Double Up Arrow is used for
In mathematical notation ⇑ is a relation: it makes a claim about the two things either side of it, which is true or false rather than a value to work out. TeX gives a relation more space than an operator, and breaks a long line at one in preference to breaking at an operator. That is the classification unicode-math gives it, and it is what decides how the symbol is set: $\Uparrow$ 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 it is upwards double arrow. That word is what somebody looking for this character is liable to type when Double Up Arrow is not the name they know it by, and the search on the symbol lists matches it as well as the Unicode name.
How Double Up Arrow 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.
Every way to write Double Up Arrow
| Form | Value |
|---|---|
| Codepoint | U+21D1 |
| Decimal | 8657 |
| UTF-8 bytes | E2 87 91 |
| UTF-16 bytes | 21 D1 |
| HTML entity | ⇑ |
| HTML numeric | ⇑ or ⇑ |
| CSS | \21D1 |
| JavaScript | \u21D1 |
| Python | \u21D1 |
| URL-encoded | %E2%87%91 |
| LaTeX, in maths mode | $\Uparrow$ |
| SVG | 21D1.svg · (SIL Open Font License) |
If ⇑ arrives as ⇑
Its three UTF-8 bytes E2 87 91 are being read one at a time as Windows-1252. The text is undamaged; the reader has to be told it is UTF-8.