Mapping sentence
Enter the sentence or title used to build the letter mapping. Each letter is keyed by how many times it has appeared (1st, 2nd, …) and mapped to its position in the alphabet.
Cipher / plain text
Decode turns occurrence-codes (e.g. 2H)
back into letters. Encode turns plain text into
occurrence-codes using the mapping above. Uncheck
Numbers first to put the letter before the number
(H2 instead of 2H).