ROT13 Encoder/Decoder
Encode or decode text using the ROT13 cipher. ROT13 is self-reversible.
What is ROT13 Encoder/Decoder?
ROT13 ("rotate by 13 places") is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. Since there are 26 letters in the English alphabet, applying ROT13 twice returns the original text, making it uniquely self-reversible. It's commonly used online to hide spoilers, puzzle solutions, and jokes.
How to Use This Tool
- Type or paste your text in the input area
- The ROT13 encoded/decoded result appears instantly
- Use the Swap button to switch input and output
- Copy the result with one click
Common Use Cases
- Hiding spoilers in online forums and discussions
- Obscuring puzzle answers and solutions
- Simple text obfuscation for games
- Learning about basic cryptography concepts
Frequently Asked Questions
Is ROT13 secure encryption?
No, ROT13 is not encryption and provides no security. It's trivial to decode since the algorithm is publicly known and simple. It's designed for casual obfuscation (hiding spoilers), not protecting sensitive data.
Why is ROT13 self-reversible?
Because there are 26 letters in the alphabet and 13 is exactly half. Shifting a letter by 13 positions twice brings it back to the original (13 + 13 = 26 = full circle).
Does ROT13 work with numbers and symbols?
No, ROT13 only transforms letters (A-Z, a-z). Numbers, spaces, punctuation, and special characters remain unchanged.