Atbash Cipher Encoder / Decoder
A becomes Z, B becomes Y: the alphabet folded onto itself. One step both encodes and decodes.
Atbash is its own inverse — running it again on the output gives back the original, so there is nothing to choose.
- Plain text
- Wizard
- Encoded
- Draziw
Other ciphers
How Atbash works
Write the alphabet forwards, write it backwards underneath, and swap each letter for the one below it: A for Z, B for Y, C for X, and so on to M for N. Every letter has exactly one partner, so applying Atbash a second time swaps each one back — encoding and decoding are the same step, as with ROT13.
There is no key and nothing to choose. Case is kept, and anything that is not A–Z passes through untouched.
A worked example
Wizard becomes Draziw — which happens to be the word spelled backwards, because W–D, I–R and Z–A are three mirror pairs. A puzzle-setter's favourite, and a reminder of how little Atbash hides.
Where it comes from, and how it is broken
The name is the method: in Hebrew the first letter, aleph, swaps with the last, tav, and the second, bet, with the second-to-last, shin — a-t-b-sh. It appears in the Book of Jeremiah, where Sheshach is generally read as an Atbash of Babel.
Because there is no key, recognising that a message is Atbash is the same thing as reading it. A substitution where the most frequent ciphertext letter is V (the mirror of E) is the tell.
Everything on this page runs in your browser — nothing you type is sent anywhere. The cipher encoder / decoder runs all five ciphers on one page, and the cipher buttons above switch this one too.
How do I decode an Atbash cipher?
Paste it into the box above. Atbash is its own inverse, so the output is the decoded text — there is no separate decode step and no key to enter.
Is Atbash the same as a Caesar cipher?
No. Caesar shifts every letter the same distance; Atbash reflects the alphabet, so each letter moves a different distance (A moves 25 places, M only one). Neither has a key worth the name.