Caesar Cipher Encoder and Decoder

It is one of the oldest ciphers: you shift every letter forward by a fixed number of places in the alphabet. With a shift of 3, A becomes D and B becomes E. Named after Julius Caesar, who reportedly used a shift of 3 for his correspondence.

Use the brute force panel. Because there are only 25 possible shifts, the tool decodes the message with every shift at once and lists them. Read down the list and pick the line that reads like real words. That is exactly why the cipher is trivial to break.

ROT13 is just a Caesar cipher with a shift of 13. Because the alphabet has 26 letters, applying a shift of 13 twice returns the original, so the same operation both encodes and decodes. Set the shift to 13 here and you have ROT13.

No. Only letters are shifted, and case is preserved, so a capital stays capital. Spaces, digits, and punctuation pass through untouched. That keeps the structure of a message readable, which unfortunately also makes it easier to crack.

Not at all. With only 25 shifts, anyone can brute force it in seconds (this page does it for you), so it is great for puzzles, teaching, and games, but useless for real secrets. For actual secrecy use real encryption, like our encrypt text tool or an end-to-end encrypted store.