A1Z26 Cipher (Letter ↔ Number)

How it is calculated

The A1Z26 cipher replaces each letter with its place in the English alphabet: A=1, B=2, … Z=26. In encode mode the engine reads the text word by word. Uppercase and lowercase letters give the same number, and any character that is not an A to Z letter (digits, punctuation, accented or non-Latin letters) is dropped. The numbers of one word are joined by spaces, and the words are joined with / . In decode mode you do the opposite: a slash separates words, whitespace separates numbers, and each number from 1 to 26 becomes a lowercase letter. Numbers outside that range and non-numeric tokens are skipped. Decoded words are separated by a single space, so the output has no capital letters or punctuation.

Common mistakes

• Decoding numbers glued together like 85121215. The engine needs spaces between numbers because it cannot tell 1 and 12 from 11 and 2.
• Writing Turkish letters such as ç, ş or ğ and expecting a number. Only the 26 letters A to Z are encoded; others are silently removed.
• Using hyphens between numbers when decoding. Separate numbers with spaces and words with a slash.
• Expecting capital letters or punctuation back after decoding. The case and punctuation of the original are not stored.