Atbash Cipher
Encode and decode text using the Atbash cipher — a simple substitution that mirrors the alphabet, mapping A↔Z, B↔Y, C↔X, and so on.
What Does This Tool Do?
The Atbash cipher is a mirror substitution — A maps to Z, B to Y, C to X, and so on. Because it is its own inverse, the same operation both encodes and decodes. It originated in the Hebrew alphabet and is referenced in the Book of Jeremiah.
Key Features
Self-Inverse
Same operation encrypts and decrypts.
Instant
Result appears immediately.
Preserves Case
Letter case maintained in output.
Copy Result
One-click copy.
How to Use
- Type or paste your text.
- Click Encode / Decode (same for both directions).
- Copy the result.
Frequently Asked Questions
What is the Atbash cipher?▾
A simple substitution cipher that reverses the alphabet: A↔Z, B↔Y, C↔X … M↔N. Originally used with the Hebrew alphabet; the name means first-last in Hebrew.
Why is it its own inverse?▾
Because the mapping is perfectly symmetric — if A→Z then Z→A. Applying Atbash twice returns the original text.
Is Atbash secure?▾
No — it has only one possible "key" so it is trivially broken. It is used for puzzles and historical study only.