Free online ROT13 encoder/decoder. ROT13 replaces each letter with the 13th letter after it. Applying twice restores the original. Supports ROT5 (number rotation) and ROT47 (ASCII extended). Pure frontend.
A special case of Caesar cipher that replaces each letter with the 13th after it. Encryption and decryption use the same operation. Not for security purposes.
ROT5 only rotates digits 0-9. ROT47 rotates all ASCII printable characters (33-126). Often combined as ROT13+ROT5.
No. ROT13 is encoding, not encryption. Anyone can easily decode it. Only use for hiding spoilers, puzzles, etc.