Example
Uryyb jbeyq
ROT13 Converter
Encode or decode ROT13 instantly in your browser. Free online ROT13 encoder/decoder for obfuscating text on forums and puzzles.
Enter the values below, then press Calculate (or press Enter). The calculator updates your results instantly. Try different values to see how your inputs change the outcome.
- Text to transform — enter a value. A typical Text to transform would be Type or paste text here….
- Review your results — the key output is highlighted, with supporting figures below.
Loading calculator…
Results
ROT13 result
| Detail | Value |
|---|---|
| Letters shifted |
What is this calculator for?
Apply the ROT13 Caesar cipher: each letter is rotated 13 positions in the alphabet, non-letters pass through.
How to Use This Calculator
Enter the values below, then press Calculate (or press Enter). The calculator updates your results instantly. Try different values to see how your inputs change the outcome.
- Text to transform — enter a value. A typical Text to transform would be Type or paste text here….
- Review your results — the key output is highlighted, with supporting figures below.
What You'll Need
- Text to transform
- a value · required
About This Calculator
ROT13 (rotate by 13) is a Caesar cipher that shifts every letter 13 positions through the alphabet: A → N, B → O, and so on.
Because there are 26 letters, applying ROT13 twice restores the original text — the same tool both encodes and decodes. Digits, punctuation, and whitespace are left untouched. It’s not encryption, but a convenient way to hide text from casual reading.
Transformations run entirely in your browser.
Worked Examples
Frequently Asked Questions
Is ROT13 secure?
No. It is a simple substitution cipher with no key — anyone can reverse it. Use it for casual obfuscation, not for protecting data.
How do I decode ROT13?
Run the same text through the tool again. Since ROT13 is its own inverse, encoding and decoding are identical.