How to use the Atbash cipher translator
- Enter a short message in the input field. The tool accepts up to 500 characters and requires at least one English A–Z letter.
- Select Convert. Atbash has no key and no separate decode rule, so the same button works for plaintext and ciphertext.
- Read the exact transformed text in the result card. Select Copy result to copy only those characters, without a label or explanation.
- If you edit the input, the old result and copied status disappear immediately. Clear removes the current input and result.
How the Atbash alphabet works
Atbash is a fixed monoalphabetic substitution. Number A as 0 through Z as 25 and replace position x with 25 − x. The pairs are A↔Z, B↔Y, C↔X, continuing to M↔N. Because every pair points back to its partner, applying Atbash twice restores the original message.
This page applies that mapping only to the 26 unaccented English letters. Uppercase remains uppercase and lowercase remains lowercase. Spaces, line punctuation, digits, emoji, accented letters, Japanese, Korean, and every other non-A–Z character stay exactly where they were. This predictable preservation makes the result useful for classroom exercises and word puzzles without silently deleting the surrounding text.
Exact Atbash examples
HELLO → SVOOL. Applying the translator again gives HELLO. Mixed case is preserved: Hello, World! → Svool, Dliow!
The published independent vector GONAVYBEATARMY → TLMZEBYVZGZINB is included in the feature test. “Meet at 7!” becomes “Nvvg zg 7!”; its space, digit, and punctuation do not change.
When this decoder is useful
- Check an Atbash homework step, make a lightweight puzzle clue, or decode a message that is already known to use the reversed alphabet.
- Compare a suspected message with the visible A↔Z rule. The page does not identify unknown ciphers or rank possible plaintext.
Supported text and limits
- Atbash is a historical puzzle and learning cipher, not modern encryption. Anyone who knows the mapping can reverse it immediately. Do not use it to protect passwords or private data.
- Only A–Z and a–z are transformed. The tool does not transliterate other alphabets, strip accents, guess missing text, store messages, upload files, or send the input to a decoding service.
Atbash cipher FAQ
Is Atbash encoding different from decoding?
No. The mapping is self-inverse, so the identical transformation handles both directions.
Why did my numbers and punctuation stay the same?
The selected convention maps only English A–Z letters. Preserving other characters keeps spacing and sentence structure predictable.
Does letter case matter?
The same alphabet positions are used for both cases, while the original case is retained in the output.
Can this find the cipher used by an unknown message?
No. It transforms text under the Atbash assumption and does not perform cipher detection or automated cryptanalysis.