Caesar Cipher Encoder Decoder
Enter text, choose a mode, and review the primary result plus every shift locally in your browser.
A QUICK WALKTHROUGH
How to use this tool
- Enter text and choose a mode.
- Set a shift from 0 to 25.
- Run the tool and review the primary result or all decode candidates.
Alphabet and shift direction
Encode moves letters forward by the selected shift. Decode moves them backward. A shift of 0 leaves text unchanged; wraparound uses the 26-letter ASCII Latin alphabets.
Local and limited by design
The primary result and all 26 decode candidates run in the browser. Case is preserved, while spaces, punctuation, digits, accented letters, emoji, and other non-ASCII characters pass through unchanged. This is not secure encryption.
GOOD TO KNOW
Common questions
What alphabet does it use?
Only ASCII A–Z and a–z are shifted, with case preserved.
Why show all shifts?
There are only 26 rotations, so the candidate list helps inspect text when the key is unknown.
Is this secure encryption?
No. Caesar cipher is useful for learning, puzzles, and demonstrations, not sensitive data.