📌 Overview

Apply a Caesar cipher to text — shift every letter by a chosen number of positions (ROT13 = shift 13). Encode a message or decode a cipher.

🔡 ROT13 / Caesar Cipher

Apply a Caesar cipher to text — shift every letter by a chosen number of positions (ROT13 = shift 13). Encode a message or decode a cipher.

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📖 Deep Dive: ROT13 / Caesar Cipher

How the Caesar cipher works

Each letter in the alphabet is shifted N places forward (wrapping back to the start at the end). ROT13 uses N=13; since there are 26 letters, shifting twice returns the original text.

Rules

  • Only A–Z / a–z are shifted, preserving case
  • Digits, spaces and punctuation are left unchanged
  • With N=13, encoding and decoding are the same operation

    • Reminder

    This is not real encryption — it provides no security and is only for fun and light obfuscation.