Caesar Cipher Tool
Shift letters by a chosen amount to encode or decode a Caesar cipher.
Quick answer: enter your details below and click Apply Shift — your result appears instantly, right here in your browser. Nothing you enter is uploaded or stored.
C
Converters & Utilities
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How to use
- Type the message to encode or decode.
- Enter a shift from 0 to 25.
- Choose encode or decode.
- Click Apply Shift and copy the result.
About this tool
A Caesar cipher moves every letter forward or backward through the alphabet by a fixed shift, wrapping from Z back to A. This tool handles upper and lower case separately and leaves spaces, digits, and punctuation untouched, so the shape of a sentence stays readable. Pick encode to scramble a message or decode to undo a shift you already know.
Frequently asked questions
What shift turns HELLO into KHOOR?
A shift of 3 in encode mode: H becomes K, E becomes H, and so on through the word.
Is a Caesar cipher secure?
No. With only 26 possible shifts it is a puzzle and a teaching aid, not real encryption.