ROT13 and ROT47 Encoder and Decoder

ROT13 replaces each letter with the one 13 places ahead in the alphabet, wrapping from Z back to A. Because 13 is exactly half of 26, doing it a second time returns the original letter. That is why the same operation both encodes and decodes, and why there is no key to remember. Case is preserved and digits, spaces and punctuation are left unchanged.

No. ROT13 is not encryption and offers no real security. There is no key, so anyone can reverse it instantly, including this same tool. It is meant for hiding spoilers, puzzle answers or offensive jokes from casual view, not for protecting anything sensitive. For genuine secrecy use a password-based tool such as the AES-GCM text encrypt and decrypt tool.

ROT13 rotates letters A-Z and a-z by 13. ROT5 rotates the digits 0-9 by 5. ROT18 combines the two, so letters and digits are both rotated at once. ROT47 instead rotates every printable ASCII character from '!' to '~' by 47, which also scrambles punctuation. All four are their own inverse, so running the same variant a second time restores the original text.

You do not run anything backwards. Each variant is self-inverse, meaning applying it once scrambles the text and applying the very same variant again unscrambles it. So to decode, paste the scrambled text, keep the same variant, and the output is your original message. The Swap button copies the result back into the input to make that easy.

ROT13 only touches letters, so digits, spaces, punctuation and emoji pass through untouched. If you also want to scramble digits, use ROT18, which adds ROT5 on top of ROT13. ROT47 goes further and rotates punctuation and digits along with letters, since it works over the whole printable ASCII range.

Yes. The rotation runs entirely in your browser using JavaScript. Your text is never uploaded to a server and nothing is stored, so you can safely paste spoilers or draft messages.