ROT13 Encoder
ROT13 is its own inverse. Applying it twice returns the original.
Last updated: 2026 · Free online tool
What is ROT13 Encoder?
Free online ROT13 encoder and decoder that applies the classic Caesar cipher by shifting each letter 13 places in the alphabet; the same operation encodes and decodes text instantly, entirely in your browser.
How to Use
- 1Enter Input— Enter the text you want to encode/decode.
- 2View Result— Check the ROT13-encoded result.
- 3Copy— Copy the result to use it.
Frequently Asked Questions
ROT13 is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. Applying it twice returns the original text.
Yes, it is completely free.
No. All processing is done in the browser.
Yes, it is responsive and works on mobile devices.
Yes, it is based on static data and can be used offline.