Number Systems and Character Codes

ASCII and Unicode tables, HTML entities, Alt codes and numeral systems, linked to Calxy binary, hex and text encoding tools.

• ASCII TableAll 128 ASCII codes with their decimal, hexadecimal, binary and octal values, the printable character or control-code name, and answers to the lookups people search for most.
• Alt CodesHold Alt and type a number on the numeric keypad to enter a character on Windows. The character you get depends on whether the number starts with 0, because the two forms use different code pages.
• Unicode CharactersA curated set of frequently used Unicode characters grouped by block, each with its code point, official character name, HTML numeric reference and UTF-8 encoding. Unicode has well over 150,000 characters, so this page covers the common ones and links to the full charts.
• HTML EntitiesNamed character references and numeric codes for the characters most often needed in HTML, from the reserved characters & < > " to symbols such as ©, €, ✓ and ♥. Every name here is in the WHATWG HTML named character reference list.
• Numeral SystemsPositional number systems write the same value with different bases. This page explains place value, the digits and prefixes used for each common base, and lists 0 to 32 in binary, octal, decimal, hex and base 36.