ROT13 Encode/Decode
Apply the ROT13 letter rotation (or ROT5, ROT18, ROT47) to encode or decode a text; the same operation reverses itself.
- Runs in your browser
- Free to use
About this tool
ROT13 shifts every letter 13 places in the alphabet and is its own inverse, which made it the traditional way to hide spoilers on Usenet. This tool applies ROT13, ROT5, ROT18 or ROT47 to any text instantly in your browser; run the result through again to decode.
For actual encoding needs see Base64 and URL encoding.
How to use it — quick steps
- 01
Enter the text
Type or paste the text in the field above, for example Hello, World!. Nothing is uploaded.
- 02
Adjust the options
Pick the settings that fit your case; the defaults work for most people. Changes apply instantly.
- 03
Press "Transform"
Press "Transform" or Ctrl + Enter. The result appears instantly below the form. Results can be copied.
Key features of this tool
Nothing leaves your browser
The processing is plain JavaScript that runs on your device: the text you paste is never uploaded to our servers or to anyone else.
Instant results
Results appear the moment you press the button, even for long inputs, and every block has copy and download actions.
Works everywhere
No installation, no account and no limits: the tool works on desktop and mobile, in any modern browser, as often as you like.
Frequently asked questions
Is ROT13 encryption?
No, it is a simple letter substitution with no key. It hides spoilers and puzzle answers from a casual glance, nothing more.
Why is encoding and decoding the same button?
Rotating by 13 twice brings the alphabet back around, so applying ROT13 to ROT13 text restores the original. The same holds for ROT5 and ROT47.
Are my files or data uploaded?
No. The tool is plain JavaScript that runs in your browser; the files or data you provide here are never uploaded to our servers.