Classic Cipher Playground

Transform puzzle text with ROT13, Caesar, Atbash, ROT47, Vigenère, Leet or Morse. These methods do not protect secrets. Choose a method, enter text and transform it. Copy exports the complete output; swapping uses it as the new input and reverses the direction where needed.

ROT13 and Atbash replace A–Z letters while preserving case and other characters. Caesar adds an integer shift modulo 26; decode subtracts it. Vigenère repeats an A–Z key and advances it only for A–Z input letters. ATTACKATDAWN with LEMON becomes LXFOPVEFRNHR. ROT47 exchanges printable ASCII characters from ! to ~ and leaves spaces and other characters unchanged.

Leet is a lossy substitution, not a reversible cipher: i and l both become 1; decoding chooses i and does not restore case. Morse supports A–Z, É, digits and selected punctuation, including common extensions. Separate letter codes with spaces and words with /. SOS HELP becomes ... --- ... / .... . .-.. .--. . Decoding gives lowercase text and normalizes whitespace. Unsupported characters or groups produce an error instead of invented output. No audio, timing or complete radio operating procedure is simulated.

Raw input, method, direction, key, shift and completed output stay in local browser storage across reloads and language changes. Editing clears the old output. The restored output is a saved snapshot; Transform recalculates it. Imports accept up to 32 MiB. Larger automatic states show a warning: they stay live while navigating within the app, and the previous saved copy returns after reload. Export before reloading. Input textareas normalize CR/CRLF line endings to LF; other whitespace is preserved.

ITU-R M.1677-1, Annex 1.

Only input values are remembered in this browser. Calculated results and experiment histories are not saved.