QP Encode/Decode

Quoted-Printable Email Encoding

Quoted-Printable Guide

Encoding Principle

  • Non-ASCII bytes are encoded as =XX format
  • ASCII printable characters (33-126) are kept as-is
  • Spaces and tabs at line end need special handling
  • Soft line breaks end with = to indicate continuation

Use Cases

  • Email body encoding (Content-Transfer-Encoding)
  • Encoding non-ASCII characters in MIME headers
  • RFC 2045 / RFC 2047 standard
  • Suitable for mostly ASCII content