Free ROT13 & Caesar Cipher Decoder / Encoder Online
Encode and decode ROT13, ROT47, and classical Caesar substitution ciphers with custom alphabetical shift keys (1 through 25). — 100% free online utility, zero sign-up, zero paywalls, and private client-side processing.
How It Works
Enter Message
Input text to encrypt or ciphertext to decode.
Select Shift Key
Use ROT13 (shift 13) or customize shift key 1-25.
View Decoded Text
Inspect deciphered output in real time.
Frequently Asked Questions
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