Caesar & Vigenère Cipher
ROT13, Caesar, Atbash & Vigenère.
Runs entirely in your browser — nothing you enter is uploaded, logged, or tracked.
A workbench for the classic substitution ciphers — ROT13, a Caesar shift by any amount, Atbash (reverse alphabet) and the Vigenère keyword cipher. Type your text, pick a cipher, and it encodes or decodes instantly. Handy for CTF challenges, escape rooms and understanding the roots of cryptography.
Frequently asked questions
What’s the difference between these ciphers?
ROT13 shifts letters by 13; Caesar shifts by any amount; Atbash maps A↔Z, B↔Y…; Vigenère shifts each letter by a repeating keyword. All are simple substitution ciphers.
Are these secure?
No — classic ciphers are trivially broken and are for learning and puzzles only. For real security use the File Encryptor or PGP tool.
Does it keep punctuation and case?
Yes — non-letters pass through unchanged and the case of each letter is preserved.