Windows
Hold Alt and type 25 on the numeric keypad.
Arrows
Copy the character, or use the shortcut that matches your keyboard and app.
Hold Alt and type 25 on the numeric keypad.
Character Viewer → arrow
Type 2193 then Alt + X
Insert → Special characters → arrow
Click the keycap, then paste with Ctrl+V or Cmd+V.
Num Lock on, hold Alt, type 25, release Alt.
Use the Unicode, HTML, CSS, or JS value below in documents and stylesheets.
U+2193↓↓\2193\u{2193}Alt + 25