Alt Code

Alt Codes on Windows

Alt codes are a Windows-specific input method for entering characters by holding the Alt key and typing a numeric code on the numeric keypad. This system dates to the IBM PC era and originally accessed characters from the IBM PC character set (Code Page 437). Today it covers both legacy code page characters and, with some configuration, Unicode characters.

How Alt Codes Work

Alt + Decimal (Code Page Characters)

Hold Alt, type a number from 1 to 255 on the numeric keypad (not the number row), then release Alt. The character corresponding to that code in the current Windows ANSI code page is inserted.

Alt + 0169 → © (Copyright sign)
Alt + 0174 → ® (Registered sign)
Alt + 0176 → ° (Degree sign)
Alt + 0163 → £ (Pound sign)
Alt + 0128 → € (Euro sign)
Alt + 0233 → é (e with acute)

Note: Codes 1-255 without a leading zero use the OEM code page (CP437), which differs from the Windows-1252 ANSI page used with a leading zero. Always use leading zeros for consistent results.

Unicode Alt Codes (Registry Method)

By default, Alt codes above 255 do not produce Unicode characters. Enabling hexadecimal Unicode input requires a registry change:

1. Open Registry Editor (regedit)
2. Navigate to HKEY_CURRENT_USER\Control Panel\Input Method
3. Create a new String Value named EnableHexNumpad with value 1
4. Restart Windows

With this enabled: hold Alt, press + on the numeric keypad, type the hexadecimal code point, release Alt.

Alt + + + 2603 → ☃ (Snowman)
Alt + + + 1F600 → 😀 (may require UTF-16 surrogate handling)

Limitations

• Numeric keypad required: The number row does not work; a numpad is mandatory. Laptop users without a numpad must use Fn+numpad keys, which varies by laptop model.
• Application dependence: Not all applications support Alt codes. Some intercept Alt key combinations for menu navigation.
• Code page dependence: Without the registry modification, results vary based on the active code page.
• BMP only: Even with hex input enabled, characters above U+FFFF (emoji, many historic scripts) are not reliably supported.
• Num Lock must be on: Num Lock must be active for the numeric keypad to produce numbers.

Alt Codes for Common Symbols

Modern Alternatives

For most users, modern alternatives are more practical:

• Windows 10/11: The emoji picker (Win+.) supports searching for symbols and emoji by name
• Character Map: charmap.exe allows browsing and copying any Unicode character
• Office applications: Alt+X converts a typed hex code to a character
• Third-party tools: Apps like "Clavier+" or AutoHotkey allow custom shortcuts for any Unicode character

Historical Context

Alt codes were introduced with the IBM PC and DOS in the early 1980s. The original 256-character IBM PC character set (Code Page 437) included box-drawing characters, Greek letters, and various symbols specifically for terminal-based UIs. Many developers and power users who learned these codes in the DOS era still use them out of habit, even though more ergonomic options now exist.