ROT13 & Caesar Cipher
Free Caesar cipher encoder and decoder online. Shift letters 1–25 (ROT13 default), decode ciphers with the same operation. Runs in your browser.
Caesar cipher (ROT13 default)
Output (same operation decodes)
Uryyb, Jbeyq!
How to use
- Paste input or drop a file above.
- Adjust options (delimiter, dialect, quality, ratio).
- Copy result or download — no sign-up needed.
FAQ
How do I decode?
Apply the same shift again — Caesar ciphers are symmetric. ROT13 decodes itself.
Are numbers affected?
No. Only A–Z letters shift; digits, spaces, and punctuation pass through.