ROT13 Encoder/Decoder
Rotate letters by 13 positions. Encoding and decoding are the same operation.
About ROT13
ROT13 is a simple substitution cipher that rotates each letter by 13 places in the alphabet. Applying ROT13 twice returns the original text.
About this ROT13 Encoder/Decoder
Encode and decode text using the ROT13 cipher. ROT13 (rotate by 13 places) is a simple letter substitution cipher that shifts each letter 13 positions in the alphabet. It's a special case of the Caesar cipher and is its own inverse - encoding and decoding use the same operation. ROT13 is commonly used for simple text obfuscation, hiding spoilers, and light text scrambling.
Key Features
Encode text using ROT13 cipher
Decode ROT13-encoded text (same operation as encoding)
Handle both uppercase and lowercase letters
Preserve numbers, punctuation, and spaces
Real-time encoding and decoding
Copy encoded or decoded text to clipboard
Works entirely in your browser
No data sent to servers - all processing is local
How to Use
Enter or paste the text you want to encode
Click 'Encode' to apply ROT13 cipher
View the encoded output (e.g., 'Hello' becomes 'Uryyb')
To decode, paste ROT13-encoded text and click 'Decode' (or 'Encode' again)
Use the copy button to copy encoded or decoded text
Note: Encoding and decoding are the same operation in ROT13
Popular Use Cases
Obfuscate text for simple hiding (not security)
Hide spoilers in online discussions
Create simple puzzles and games
Learn about basic cipher algorithms
Scramble text for fun or educational purposes
Hide answers to quiz questions
Create simple text obfuscation for non-sensitive content
Demonstrate basic cryptography concepts
Tips & Best Practices
ROT13 is its own inverse - encoding twice returns the original text
ROT13 only affects letters (A-Z, a-z), leaving numbers and punctuation unchanged
ROT13 is NOT encryption - it provides no security, only simple obfuscation
Commonly used in online forums to hide spoilers
Each letter is shifted 13 positions: A→N, B→O, M→Z, etc.
Use ROT13 for fun or learning, not for actual security
Remember that ROT13 is easily reversible by anyone
Frequently Asked Questions
What is ROT13?
ROT13 is a simple substitution cipher that shifts each letter 13 positions in the alphabet. It's a special case of the Caesar cipher and is its own inverse - applying ROT13 twice returns the original text.
Is ROT13 secure?
No, ROT13 provides no security. It's simple obfuscation that can be easily reversed by anyone. Never use ROT13 for actual encryption or security purposes.
Why is ROT13 its own inverse?
Because the alphabet has 26 letters, shifting by 13 positions twice brings you back to the original letter. Encoding and decoding use the same operation.
What characters does ROT13 affect?
ROT13 only affects letters (A-Z and a-z). Numbers, punctuation, spaces, and special characters remain unchanged.