ROT13 Encoder

ROT13 Encoder applies the ROT13 substitution cipher — rotating each letter 13 positions in the alphabet — to encode or decode text. Since ROT13 is its own inverse, the same operation both encodes and decodes.

ROT13 is used on forums and in README files to obscure spoilers, answers to puzzles, or mildly sensitive text from casual readers. It is not encryption — anyone who knows ROT13 can read it instantly.

Tip: ROT13 only affects letters A–Z and a–z. Numbers, punctuation, and spaces pass through unchanged, so ROT13 text is still recognisably text-shaped even when encoded.