🔄ROT13 Encoder

Encode and decode text using the ROT13 substitution cipher.

Input Text

Enter text above to encode or decode with ROT13.

About ROT13

ROT13 shifts each letter by 13 positions in the alphabet
Applying ROT13 twice returns the original text (it is its own inverse)
Non-alphabetic characters (numbers, punctuation, spaces) are left unchanged
Both uppercase and lowercase letters are supported
ROT13 is a simple substitution cipher, not suitable for real security

About ROT13 Encoder

ROT13 Encoder applies the ROT13 substitution cipher — rotating each letter by 13 positions in the alphabet — to any text you enter. Because the alphabet has 26 letters, applying ROT13 twice returns the original text, making it both the encoding and decoding function.

How to Use ROT13 Encoder

1
Enter your text
Type or paste the text you want to encode or decode into the input field.
2
Apply ROT13
Click 'Encode / Decode' — the same action both encodes and decodes ROT13 text since the cipher is self-reciprocal.
3
Copy the result
Copy the output text from the result field to share or use as needed.

Common Use Cases

Hiding spoilers in forum posts and online discussions
Teaching introductory cryptography concepts with a simple example
Obfuscating text in game walkthroughs or puzzle solutions
Quickly checking whether a piece of text is ROT13-encoded

Frequently Asked Questions

What is ROT13 used for?

ROT13 is commonly used in online forums and communities to obscure spoilers or punchlines from casual readers — not for real security. It is also used as a fun puzzle cipher and for basic text obfuscation.

Is ROT13 secure?

No — ROT13 is not secure in any meaningful sense. It is a trivial cipher that anyone can decode instantly. Use AES or modern encryption for anything that requires actual security.

Does ROT13 work on numbers and symbols?

No — ROT13 only rotates alphabetical characters (A–Z and a–z). Numbers, spaces, and symbols are passed through unchanged.