Caesar Cipher
Encode or decode by shifting letters (0–25). Shift 13 is ROT13.
About Caesar Cipher
Shift each letter by a number. To decode, use the same shift in the opposite direction (or shift by 26 minus the number). Not secure — for fun or learning only.
Frequently Asked Questions
What is a Caesar cipher?
Each letter is shifted by a fixed number (e.g. 3: A→D, B→E). Decoding uses the same shift in reverse. It is easy to break by trying all 26 shifts.
Does it affect numbers or symbols?
No. Only A–Z and a–z are shifted. Numbers and punctuation stay as is.
Is my text sent to a server?
No. Everything runs in your browser.