Atbash Cipher
Mirror the alphabet (A↔Z, B↔Y) to encode or decode Atbash text.
Mirror the alphabet
Atbash is one of the oldest known ciphers, originally used with the Hebrew alphabet. It simply reverses the letter order — A becomes Z, B becomes Y — and because the mapping is symmetric, encoding and decoding are the same step.
"Hello World" becomes "Svool Dliow", and running that back through the tool returns the original. Numbers and punctuation are left alone, and letter case is preserved.
Simple and private
It is a keyless puzzle cipher with no security value, but the transformation runs entirely in your browser so your text never leaves your device.
Frequently Asked Questions
What is the Atbash cipher?
An ancient substitution cipher that reverses the alphabet: A maps to Z, B to Y, and so on. It is its own inverse, so one operation both encodes and decodes.
Does it change numbers or symbols?
No. Only letters are mirrored; digits, spaces, and punctuation pass through unchanged, and case is preserved.
Is it secure?
Not at all — it is a fixed substitution with no key, useful for puzzles and history, never for protecting real information.
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