Caesar Cipher, ROT13 & Vigenère
Encrypt and decrypt with the Caesar shift, ROT13 or the Vigenère cipher — including a brute-force view of all 25 Caesar shifts.
How to use
- 1Enter your message and choose a cipher.
- 2Set the shift or keyword, then switch between encrypt and decrypt.
Frequently asked questions
How does the Caesar cipher work?
Each letter is shifted a fixed number of places along the alphabet. With a shift of 3, A becomes D and Z wraps round to C.
What is ROT13?
A Caesar shift of 13. Because the alphabet has 26 letters, applying ROT13 twice returns the original text.
Are these ciphers secure?
No — they are puzzles and teaching tools and can be broken in seconds. Use proper encryption such as AES for real secrets.