What Are Alt Codes and How Do They Actually Work?

Explainers · 6 min read · Published August 5, 2026 · Updated August 26, 2026

An "Alt code" is a way to type a character that isn’t printed on your keyboard by holding the Alt key and typing a number on the numeric keypad. Release Alt, and the character appears. It’s a feature that has shipped with Windows for decades, and it still works today — but there’s a catch that almost every symbol website online gets wrong.

The short version: real Alt codes only reliably cover character numbers 0 to 255. A huge number of the "Alt codes" you’ll find elsewhere — things like Alt+8734 for the infinity sign — simply do nothing on a normal Windows PC. This guide explains why, so you never waste time typing a code that can’t work.

Quick reference: every method

Every Alt code below is verified against the real Windows code pages — where none exists we say so, rather than list one that won’t work.

The two kinds of Alt code

There are exactly two valid Alt-code methods on a default Windows install, and they read from two different legacy "code pages" (character tables built into Windows for backward compatibility).

1. Alt + 0nnn (with a leading zero) uses the Windows-1252 code page. It is valid for numbers 128–255 and covers accented Latin letters (á, é, ñ), currency signs, curly quotes, the em dash, the trademark sign, and similar. Example: Alt+0169 → ©.

2. Alt + nnn (no leading zero) uses the older DOS/OEM code page 437. It is valid for numbers 1–255 and covers card suits (♥♦♣♠), smiley faces, arrows, box-drawing lines, and a handful of Greek and math symbols that predate Windows. Example: Alt+3 → ♥.

Why "Alt+8734" and codes like it don’t work

Both code pages only hold 256 characters (0–255). Anything with a number above 255 — which is most of Unicode’s 150,000+ characters — has no standard Alt code at all. When a site shows you Alt+8734 for ∞, it has simply taken the character’s decimal Unicode value (8734) and stuck "Alt+" in front. On a stock Windows machine that produces nothing, or the wrong character.

There is an obscure registry tweak (EnableHexNumpad) that changes this behaviour, but it is off by default and virtually nobody has it enabled. We don’t list codes that only work after a registry hack, and we mark characters with no real Alt code honestly as "not available."

What to do when there’s no Alt code

Two reliable options cover every character in existence. First, copy and paste — click any symbol on this site and paste it anywhere with Ctrl+V. Second, in Microsoft Word, type the character’s hex code then press Alt+X. For example, type 221E and press Alt+X and Word converts it to ∞. This works for the entire Unicode range, which is why every symbol in our library lists a Word Alt+X code even when no keypad Alt code exists.

Handy tips

• The leading zero matters: Alt+0169 (©) and Alt+169 (½ on many systems) are different characters.
• Alt codes need the numeric keypad with Num Lock on — the number row across the top of the keyboard does not work.
• Most laptops without a separate keypad can use Fn + the embedded number keys, or you can just copy and paste instead.
• On Mac there is no "Alt code" system; you use Option-key shortcuts or the Character Viewer instead.

Frequently asked questions

Related symbols