Caesar cipher decoder and encoder
Encode or decode a Caesar shift, apply ROT13, or inspect every possible letter shift for a puzzle.
Bookmark this page
Keep this page handy for next time.
- On a computer
- Press Ctrl + D, or Command + D on a Mac.
- On a phone or tablet
- Open your browser's menu or Share menu and look for Add Bookmark, Bookmark or Add to favourites.
A bookmark saves the page link. Save any tool results separately.
How to use this tool
- Paste the message and choose a known shift, ROT13 or all shifts.
- Run the tool. For all shifts, read the labelled candidates and choose the meaningful text.
Things to know
- Up to 20,000 input characters. Shifts apply only to A-Z and a-z; case, spacing, punctuation and other scripts are preserved.
- All shifts produces 26 candidates without guessing which is correct. Caesar and ROT13 are puzzle ciphers and do not protect secrets.
- Processing stays on your device. Results are not saved between visits.
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