Bacon's Cipher
AABBB AABAA ABABB ABABB ABBBA BABBA ABBBA BAAAB ABABB AAABB
Encode text into A's and B's
Every letter maps to its own five-character code (A = AAAAA, B = AAAAB, … Z = BBAAB) using the distinct 26-letter alphabet, so the message round-trips cleanly. Spaces, digits, and punctuation are left in place between the encoded groups.
When to use this tool
Reach for Bacon's cipher when a puzzle, CTF challenge, escape room, or classroom crypto lesson calls for a biliteral substitution — one that hides each letter behind a five-symbol group of two characters. It rounds out the classical ciphers here (Caesar, Vigenère, Atbash, Rail Fence): instead of shifting or reordering letters, it replaces every A–Z letter with its own A/B code, and reading those codes five at a time recovers the message.
Privacy and limitations
Everything runs locally in your browser; nothing is sent anywhere. This is a classical cipher, not real encryption — the fixed letter-to-code table is trivial to reverse once you spot the two repeating symbols. This tool uses the distinct 26-letter variant so every letter has a unique code and encoding then decoding round-trips the letters exactly; the historical 24-letter alphabet merged I/J and U/V and is out of scope, as is the steganographic trick of hiding the A/B pattern in two typefaces. Decoding returns letters in uppercase and ignores spaces and other separators, so spacing and letter case from the original text are not restored.