About this tool
Apply a Caesar cipher by shifting letters a chosen number of places. ROT13 is its own inverse and runs fully in your browser.
Frequently asked questions
Why does ROT13 decode itself?
Shifting by 13 twice returns to the original letter, so the same operation encodes and decodes.
What about non-letters?
Only A to Z and a to z are shifted within their case; digits, spaces and symbols are left untouched.