ROT13 Encoder/Decoder
Encode or decode text with ROT13 instantly. ROT13 is its own inverse, so one button does both.
What is a ROT13 Encoder/Decoder?
ROT13 is a substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. Because there are 26 letters, applying ROT13 twice restores the original text.
ROT13 is widely used online to hide spoilers, puzzle answers, and mildly offensive content in a way that is trivially reversible. It is not encryption - it provides no security - but it prevents casual accidental reading. The Usenet community popularised ROT13 in the 1980s and it remains in common use on forums, Reddit, and game walkthrough sites.
How to Use ROT13 Encoder/Decoder
- 1Paste your plain text to encode it, or paste ROT13 text to decode it.
- 2The output updates instantly.
- 3Copy the result.
Features
- ✓Self-inverse: encodes and decodes with the same operation
- ✓Live output as you type
- ✓Only shifts letters; leaves numbers and punctuation unchanged
- ✓Runs entirely in your browser
Common Use Cases
Hiding spoilers
A forum user encodes a film spoiler with ROT13 before posting, so readers who want to avoid it are not accidentally exposed to the reveal.
Puzzle and game design
A puzzle designer hides hint text inside a game using ROT13 so players can look up hints without seeing answers they did not ask for.
Usenet and forum conventions
A developer familiar with classic Usenet encodes a sensitive but non-secret answer in ROT13 following the long-standing community convention.