How to use the ROT13 Encoder
- 1. Type or paste textAdd the text you want to scramble or unscramble.
- 2. Pick ROT13 or ROT47ROT13 changes letters; ROT47 changes all visible ASCII.
- 3. Copy the resultRun it again on the output to get the original.
How ROT13 works
ROT13 rotates each letter 13 places: A ↔ N, B ↔ O, and so on. Because the alphabet has 26 letters, rotating twice by 13 brings you back to the start, so encoding and decoding are the same operation. It is a Caesar cipher with a fixed shift of 13.
Worked example: "Hello, World!" becomes Uryyb, Jbeyq!. H → U, e → r, l → y, o → b. The comma, space and exclamation mark stay put, and capitals stay capitals. Put Uryyb, Jbeyq! back in and you get Hello, World!.
ROT47 and where ROT13 is used
ROT47 works the same way across the 94 visible ASCII characters from ! to ~, rotating by 47, so it scrambles digits and punctuation as well. "Hello, World!" in ROT47 is w6==@[ (@C=5P.
- Spoilers and puzzles: forums used ROT13 so readers had to choose to see the answer.
- CTF challenges: ROT13 and ROT47 are common first layers in beginner puzzles.
- Teaching: a simple way to show that encoding is not encryption.
ROT13 offers no security at all; anyone can reverse it instantly. For a cipher with a key, try the Vigenère tool or any shift with the Caesar cipher tool. For real protection, use the AES text encryption tool. In Python, codecs.encode(text, 'rot13') gives the same ROT13 result.
Frequently asked questions
Is ROT13 encryption?
No. It has no key and is reversed by anyone in one step. It only hides text from a casual glance.
Does it change numbers?
ROT13 does not. ROT47 does, along with symbols.
Is the ROT13 Encoder free?
Yes, the ROT13 Encoder is free. The first time you see your first result, you are asked for your name and WhatsApp number once. After that, this and every other Uncodemy tool opens straight away without the form.