Developer Essentials · Free Tool

Caesar Cipher

Shift letters by any amount to encode or decode a Caesar cipher — with a one-click brute-force view that shows all 26 possible shifts to crack an unknown message. 100% in your browser.

Shift

Show all 26 shifts

Input

Output

How it works

The Caesar cipher shifts every letter a fixed number of places through the alphabet — a shift of 13 is the special case known as ROT13. Decoding is just shifting the other way. Because there are only 25 possible keys, it offers no real security: the brute-force view shows all 26 shifts at once so you can read an intercepted message instantly.