Donaldson R F ROT13 & Caesar Cipher
Shift the letters of a message by any amount to encode it — or try every shift at once to decode a message when you don't know the key.
Try every shift (to crack a Caesar message)
How these ciphers work
The Caesar cipher replaces every letter with the letter a fixed number of places further along the alphabet — with a shift of 3, A becomes D and Z wraps around to C. Upper and lower case are kept, and digits, spaces and punctuation are left alone. ROT13 is the special case with a shift of 13: because the alphabet has 26 letters, applying it twice gives back the original, so the same operation encodes and decodes. ROT5 does the same for digits (0–9), and ROT47 rotates all 94 printable ASCII characters. These are puzzles and spoiler-hiding tricks, not real encryption — anyone can break them in seconds (that is what the table of all 25 shifts shows), so never use them to protect anything private. For real protection use our Text Encryption (AES) tool. Everything runs in your browser.