Codes / Classical ciphers
ROT13 and ROT47 Converter
Convert text with ROT13, which rotates letters by 13 places, or ROT47, which also rotates digits and punctuation; the same step encodes and decodes.
ROT13 and ROT47 Converter: ROT13 moves every letter 13 places along the alphabet, so A becomes N and N becomes A, and doing it twice returns the original. It has long been used online to hide spoilers and puzzle answers. ROT47 works the same way on all 94 printable ASCII characters from ! to ~, rotating them by 47, so numbers and punctuation are hidden too. Runs 100% locally in your browser with zero server file uploads.
- Category
- Text tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
ROT13 shifts each letter 13 places, so applying it twice gives the original text back; digits and punctuation stay as they are.
Where ROT13 is still used
Forums and puzzle sites use ROT13 to hide spoilers, punchlines, and answers so that readers only see them on purpose. It also appears in coding exercises and capture-the-flag puzzles.
For other shifts, use the Caesar cipher; to encode binary data as text, Base64.
ROT47 and ASCII
ROT47 treats the 94 printable ASCII characters as one ring; 47 is half of 94, which is why ROT47 also reverses itself.
How to use it
- Paste the text.
- Choose ROT13 or ROT47.
- Copy the result; run it again to get the original back.
Privacy & limitations
Your text stays in your browser.
Related tools
Frequently asked questions
Is ROT13 encryption?
Not in any useful sense: there is no key, and anyone can reverse it. It hides text from a casual glance, such as a spoiler.
Why does ROT13 decode itself?
The alphabet has 26 letters, and 13 + 13 = 26, so two shifts of 13 bring every letter back where it started.
Which characters does ROT47 change?
Every printable ASCII character from ! (33) to ~ (126); spaces, accented letters, and other characters stay as they are.
Free tool · runs in your browser · no account required