ASCII and Character Encoding Basics

How ASCII codes work — decimal, hex, encode/decode text, and when to use an ASCII decoder online.

ASCII assigns numeric codes to 128 characters (0–127). Extended ASCII and Unicode expanded this to support international characters. UTF-8 encodes Unicode using variable-length byte sequences — but debugging often starts with raw decimal or hex codes.

Common ASCII codes

  • A = 65, a = 97
  • 0 = 48
  • Space = 32
  • Newline (LF) = 10
  • Tab = 9
  • Hello = 72 101 108 108 111 (decimal)

When you need an ASCII decoder

  • Log files show decimal character codes instead of text
  • Serial or protocol dumps use hex byte values
  • CTF challenges and encoding homework
  • Verifying output from scripts that print char codes

ASCII workbench features

  • Char → Code tab with decimal and hex table per character
  • Code → Char tab accepts decimal (72 101) or hex (0x48) codes
  • Dedicated ASCII decoder URL for reverse conversion
  • Shareable links preserve input and active tab
Open ASCII Decoder online freeOpen full ASCII workbench