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Caesar Cipher Decoder

Encode/decode text with Caesar cipher shifts.

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About Caesar Cipher Decoder

Encode and decode messages using the Caesar cipher (shift cipher). Choose a shift value from 1 to 25, or brute-force all possible shifts to crack an encoded message.

How to Use

  1. 1

    Enter message

    Type or paste the message to encode or decode.

  2. 2

    Set shift value

    Choose a shift value (1–25) or use brute-force mode.

  3. 3

    View result

    The encoded/decoded text appears instantly.

Examples

Encoding
Input: HELLO (shift 3)
Output: KHOOR
Decoding
Input: KHOOR (shift -3)
Output: HELLO

Frequently Asked Questions

What is a Caesar cipher?
A Caesar cipher shifts each letter in the text by a fixed number of positions in the alphabet. For example, with a shift of 3, A becomes D.
What is ROT13?
ROT13 is a special case of the Caesar cipher with a shift of 13. It's its own inverse — applying it twice gives back the original text.
Can I crack an encoded message?
Yes! Use the brute-force mode to see all 25 possible shifts and identify the correct decryption.