Encode and decode text with the Caesar cipher by shifting each letter a fixed amount. Runs entirely in your browser.
The Caesar cipher is one of the oldest known ciphers, named after Julius Caesar who used it to protect military messages. It replaces each letter with another a fixed number of positions down the alphabet. This tool shifts text by any amount and shifts it back, for puzzles, CTFs and learning how substitution ciphers work.
Input:
Attack at dawn (shift 3)
Output:
Dwwdfn dw gdzq
Is the Caesar cipher secure?
No. There are only 25 possible shifts, so it is trivially broken by trying them all. It is for learning and puzzles, not real protection.
How is it different from ROT13?
ROT13 is just a Caesar cipher with a fixed shift of 13, which makes it self-inverse.
Are numbers and symbols changed?
No. Only letters are shifted; digits, spaces and punctuation are left as they are.
Does my text leave the browser?
No. Everything runs locally in your browser.
Encode and decode text with the Caesar cipher, shifting each letter by a fixed amount. Runs entirely in your browser.
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