How to type any symbol on Windows

Alt codes are the Windows method and they come with a condition nobody prints: the digits must go in on the numeric keypad, with Num Lock on. The number row along the top does not work, which is why the codes appear to fail on most laptops.

Hold Alt, type the digits on the keypad

Alt+0176 gives °. A code written with a leading zero is read as Windows-1252 and a code without one as the older OEM set, so Alt+0176 and Alt+176 are two different characters. Both are printed on this site where both exist.

Codes above 255 need something else

Windows will not accept a decimal Alt code above 255 without a registry change (HKCU\Control Panel\Input Method, EnableHexNumpad set to 1, then restart). Every list that prints Alt 8658 beside Alt 0169 as though they were the same kind of thing is wrong about that.

The emoji panel is also a symbol panel

Press Windows+. (or Windows+;). The tabs along the bottom include symbols, arrows, currency and maths, and it inserts real characters rather than pictures. This is the fastest route on a laptop.

Character Map, for everything else

Run charmap. Tick Advanced view to search by Unicode name and to read the codepoint. It shows which fonts contain a character, which is the answer when a symbol pastes as an empty rectangle.

The characters people ask about most

Every other place you might be typing, or a page for each character.