Caesar Cipher & ROT13
Shifts letters by a fixed amount — ROT13 (self-inverse) or a custom Caesar shift of 1–25 — preserving case and passing non-letters through unchanged, with a decrypt hint for custom shifts, useful for decoding obfuscated spoilers, puzzle hints, and legacy ROT13-protected content.
Caesar Cipher & ROT13 — Free Online Tool
Shifts letters by a fixed amount — ROT13 (self-inverse) or a custom Caesar shift of 1–25 — preserving case and passing non-letters through unchanged, with a decrypt hint for custom shifts, useful for decoding obfuscated spoilers, puzzle hints, and legacy ROT13-protected content.
How to use the Caesar Cipher & ROT13
- Open the tool above — it runs entirely in your browser, so your input never leaves this page.
- Paste or type your input into the field, then press the relevant button (e.g. Encode / Decode, Generate, or Convert).
- Copy the result from the output area with the copy button orCtrl/Cmd + C.
- No signup, no upload, and no tracking — repeat as often as you need.
Frequently asked questions
Is the Caesar Cipher & ROT13 free to use?
Yes. The Caesar Cipher & ROT13 is completely free, with no signup, no ads inside the tool, and no hidden limits.
Does the Caesar Cipher & ROT13 upload my data?
No. The Caesar Cipher & ROT13 processes everything locally in your browser. Your input is never sent to a server, so it stays private even on shared devices.
Does the Caesar Cipher & ROT13 work offline?
After the page loads, the Caesar Cipher & ROT13 runs entirely in your browser, so it keeps working without a network connection.
Free & private — why use this Caesar Cipher & ROT13
The Caesar Cipher & ROT13 runs 100% client-side in your browser. Your data is never uploaded to a server, no account is required, and the tool is completely free. It works offline once the page has loaded and is part of a growing collection of privacy-first developer utilities.