Local · Private · Free

Caesar / ROT13 Cipher

Encode and decode Caesar, ROT13, ROT47, Atbash and A1Z26 — and crack unknown shifts with a frequency-scored brute-force panel.

Between letters of a word, e.g. 8-5-12-12-15.
Between words. Decoding reads any digits it finds.

This cipher is self-inverse — encoding and decoding are the same operation.

🔒 Everything runs on your device — your text never leaves the browser.

Brute-force Caesar

All 25 shifts of the input, scored by English letter frequency (χ² — lower is more likely English). Top 3 are highlighted. Click a row to copy its full text.

About Caesar / ROT13 Cipher

Caesar / ROT13 Cipher is a free, private text & code tool that runs entirely in your web browser. Encrypt/decrypt with Caesar shift, ROT13 & Atbash — with brute-force decode. Because everything happens locally on your device, your files and data are never uploaded to a server, there is no sign-up or installation required, and it keeps working offline. It is handy for caesar cipher, rot13, atbash, shift cipher. Like every HeroTool by Digital Heroes, Caesar / ROT13 Cipher is 100% free with no limits.

How to use Caesar / ROT13 Cipher

  1. Open Caesar / ROT13 Cipher — it runs entirely in your browser, with no signup.
  2. Paste or type your text or code into the editor.
  3. Adjust the options to match exactly what you need.
  4. Copy or download your result — it is free, and your data stays on your device.

Frequently asked questions

Is Caesar / ROT13 Cipher free?

Yes — Caesar / ROT13 Cipher is completely free for everyone. No sign-up, no account and no usage limits.

Is it private? Are my files uploaded anywhere?

No. Caesar / ROT13 Cipher runs entirely in your browser on your own device, so your data never leaves your computer and nothing is uploaded to a server.

Does it work offline?

Yes. HeroTools is a Progressive Web App — once the page has loaded it keeps working offline, and you can install it as an app from your browser.

Do I need to install anything or create an account?

No. Just open the page and start using it. Installing it as an app is optional and only adds offline convenience.

What does Caesar / ROT13 Cipher do?

Encrypt/decrypt with Caesar shift, ROT13 & Atbash — with brute-force decode.