Caesar Cipher
Encode and decode text with the classical Caesar shift cipher using a custom shift amount (1–25).
100% client-side · no upload
How to use
- Set the shift amount (1–25) — Julius Caesar used 3.
- Type or paste the text you want to encrypt or decrypt.
- Choose Encode or Decode, then click "Apply Caesar Cipher".
Related tools
- ROT13 — Caesar cipher with fixed shift 13
- Atbash Cipher — mirror-alphabet substitution
- Morse Code Translator — dots and dashes
More ways to use this tool
Frequently Asked Questions
- What is the Caesar cipher?
- The Caesar cipher shifts each letter in the alphabet by a fixed number of positions. With a shift of 3, A becomes D, B becomes E, etc. It is one of the oldest known encryption techniques, used by Julius Caesar in his private correspondence.
- Does my data leave my device?
- No. The Caesar cipher transformation is pure JavaScript running entirely in your browser.
- Does it work on mobile?
- Yes. The tool works in any modern mobile browser.
Last updated: By jarvisbox