What ↡ means
It marks a downward direction; context supplies the specific relation.
It appears in diagrams and technical notation. Unicode also lists “form feed” and “fast cursor down,” names tied to page and cursor movement.
Arrow notation moved from diagrams into logic
A 1737 waterwheel treatise used arrow-like marks to show flow. By 1922, formal logic—a system for writing rules of reasoning—used arrows for “if this, then that”; by 1933, double-headed arrows marked equivalence, a relation that works both ways.
Technical and diagrammatic in tone.
Don't confuse it with
1Questions people ask
1Why does ↡ look different?
It can. Each font draws this text character, so line weight, spacing, and arrowhead shape may vary.
How to type ↡
Windows (Word)
Alt+XType 21A1, then Alt+X to get ↡.
Windows
Win+Rrun charmap for the full table, or use the emoji picker's Ω symbols tab (Win + .).
macOS
Control+Command+SpaceOpen the character viewer and search “downwards two headed arrow”.
Linux
Ctrl+Shift+UType 21a1, then Enter or Space.
HTML
↡CSS
\21A1↡ HTML code
Use `↡` or the named HTML entity `↡`.
CSS
Write `\21A1` followed by a space in a CSS escape.
JavaScript or JSON
Write `\u21A1` in a JavaScript or JSON string.
Codes and encoding1 code points
HTML decimal
↡
HTML hex
↡
CSS content
content: "\21A1";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%86%A1
1
On screen
1
Code points
1
JS .length
3
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.