Atbash cipher
A becomes Z and B becomes Y. Type or paste text and read the result at once.
Paste the result back in and you get your original text: the same step encodes and decodes.
Full chart
- AZ
- BY
- CX
- DW
- EV
- FU
- GT
- HS
- IR
- JQ
- KP
- LO
- MN
- NM
- OL
- PK
- QJ
- RI
- SH
- TG
- UF
- VE
- WD
- XC
- YB
- ZA
How the Atbash cipher works
Atbash reverses the alphabet: the first letter swaps with the last, the second with the second from the end, and so on. A becomes Z, B becomes Y, C becomes X, and M and N swap in the middle.
The name comes from the Hebrew alphabet, where the first letter pairs with the last and the second with the second from the end: aleph–tav, bet–shin. Because every letter swaps with its partner, encoding and decoding are the same step. Numbers, spaces and punctuation stay as they are.
Example: HELLO
Replace each letter with its mirror partner:
- HS
- EV
- LO
- LO
- OL
Result: SVOOL
Other ciphers
ROT13 shifts the alphabet by half instead of reversing it. For numbers, see A1Z26; for pairs of digits, the Polybius square. All of them are on the scout codes page.