Encode and decode secret messages using Caesar cipher, ROT13, Atbash, Morse code, and more. Perfect for kids, classrooms, and puzzle lovers.
Cipher Settings
125
Encoded Message
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Cipher Key
Frequently asked questions
What is a Caesar cipher?
A Caesar cipher shifts each letter of the alphabet by a fixed number of positions. Julius Caesar reportedly used a shift of 3, turning A into D, B into E, and so on. It is one of the oldest and simplest encryption methods.
What is ROT13?
ROT13 is a special case of the Caesar cipher with a shift of 13. Because the alphabet has 26 letters, applying ROT13 twice returns the original text, making it its own decoder.
Is this tool free?
Yes — completely free with no account or signup required.