Binary ↔ ASCII Reference Table

Full 0-255 decimal, hex, binary, and character mapping

How to Use This Table

This table maps each ASCII character (0-255) to its decimal, hexadecimal, and binary representations. Use it when you need to quickly look up a character code during debugging, encoding work, or learning how computers represent text.

Columns: Dec (decimal number) | Hex (hexadecimal) | Bin (8-bit binary) | Char (the character, or control code name for values 0-31)

Quick tip: The decimal value for uppercase 'A' is 65, lowercase 'a' is 97. The difference between uppercase and lowercase is always 32 — that's bit 5 in the binary representation.

DecHexBinaryCharacter

Common Lookups

Here are the ASCII values developers and students look up most often:

  1. NUL (0) — String terminator in C and many protocols
  2. TAB (9) — Horizontal tab, used in indentation and TSV files
  3. LF (10) — Line feed, Unix/macOS line ending
  4. CR (13) — Carriage return, often paired with LF in Windows line endings
  5. Space (32) — The most frequent ASCII character in text
  6. Digits 0-9 (48-57) — Convert a digit character to its numeric value by subtracting 48
  7. Uppercase A-Z (65-90) — 'A' starts at 65
  8. Lowercase a-z (97-122) — 'a' starts at 97
  9. DEL (127) — The "delete" control character