Atbash
Mirror the alphabet — A↔Z, B↔Y, C↔X, and so on.
Output
Visualization
Nothing to visualize yet — type into the input above.
// about
A classical cipher — the kind of thing people used before computers. Fun and educational, but not cryptographically secure. Hit Share link to copy a URL that encodes your current state — recipients open it and their browser reconstructs everything locally. Nothing touches a server.