Atbash Cipher
Encode and decode the Atbash (mirror-alphabet) cipher.
- Runs locally in your browser
- No upload required
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Supported formats
Privacy
Runs entirely in your browser. Your input is never uploaded, stored, or sent to a third party.
Atbash applied — the cipher is its own inverse.
How it works
- Replaced A with Z, B with Y, and so on to the end of the alphabet.
- Kept letter case and copied non-letters unchanged.
- Atbash is self-inverse, so Encode and Decode produce the same result.
Methodology
- Read the input text one character at a time.
- Apply the cipher or encoding transformation for the chosen direction.
- Return the transformed text with a short summary.
Usage
- Paste or type the text to convert.
- Choose Encode or Decode.
- Read the converted text and copy it.
Examples
These are examples, not current values: they use fixed inputs, while the interactive tool computes live results in your browser.
Encode a sample
{
"text": "Hello, World!",
"direction": "encode"
}Decode a sample
{
"text": "Svool",
"direction": "decode"
}Limitations
How the Atbash Cipher works
Encode and decode the Atbash (mirror-alphabet) cipher. The transformation is a single deterministic pass, so the same input always produces the same output.
Frequently asked questions
- Is this cipher secure?
- No. Classical substitution and transposition ciphers are educational and are not suitable for protecting real secrets.
- Does everything round-trip?
- Reversible ciphers round-trip for alphabetic input; encodings that normalise case or drop characters document that in their notes.
Sources
- ECMA-262: ECMAScript Language Specification — Ecma International
- MDN Web Docs — JavaScript String and code point reference — MDN
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