Atbash Cipher Encoder & Decoder
Encode and decode the Atbash cipher — the reverse-alphabet substitution where A becomes Z, B becomes Y, and so on. Instant and works both ways.
What is the Atbash cipher?
The Atbash cipher is one of the oldest known ciphers. It is a substitution cipher that simply reverses the alphabet: A becomes Z, B becomes Y, C becomes X, and so on down to Z becomes A. It began as a cipher for the Hebrew alphabet and appears in ancient texts.
How to use this Atbash tool
- Type your message (or paste Atbash text) into the box.
- The converted text appears instantly.
- Tap Copy to save the result.
How Atbash works
Atbash is a fixed mapping, so there is no key to choose. Because reversing the alphabet twice returns you to the start, Atbash is its own inverse: the same operation encodes and decodes. Only the 26 letters change, while numbers, spaces, and punctuation stay exactly as they are and letter case is preserved.
Where Atbash is used
Today Atbash turns up in puzzles, escape rooms, geocaching, and beginner cryptography lessons, where its simple reverse-alphabet rule makes it easy to learn and quick to solve by hand.
More codes and ciphers
Explore the rest of the family: the Caesar Cipher, Atbash, Vigenère, and A1Z26. For other encodings, try the Morse Code Translator and the Binary Translator.
Free and private
This Atbash cipher tool runs entirely in your browser — free, with no sign-up, and nothing you type is uploaded or stored.
Frequently asked questions
- What is the Atbash cipher?
- Atbash is a substitution cipher that reverses the alphabet: A becomes Z, B becomes Y, C becomes X, and so on. It originated with the Hebrew alphabet and is one of the oldest known ciphers.
- How do I decode Atbash?
- Atbash is its own inverse — encoding and decoding are the same operation. Just paste your text and the tool applies the reverse-alphabet mapping, so encoded text turns back into plain text automatically.
- Does Atbash change numbers or spaces?
- No. Only letters A–Z are swapped; numbers, spaces, and punctuation pass through unchanged, and letter case is preserved.
- Is it free and private?
- Yes — it runs entirely in your browser with no sign-up, and nothing you type is uploaded or stored.
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