Caesar Cipher Encoder and Decoder
About this tool
Shift letters to encode or decode a classic Caesar cipher.
Privacy
Your input is processed locally in your browser and is not uploaded.
Frequently asked questions
Is my input uploaded?
No. All calculations and conversions run locally in your browser.
Is a Caesar cipher secure encryption?
No. It is a historical substitution cipher suitable for learning and puzzles, not security.
Does it work on mobile?
Yes. The interface adapts to mobile and desktop screens.