🔐 ROT13 Encoder Decoder

Encode and decode text using the ROT13 cipher, a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. ROT13 is reversible (applying it twice returns the original text) and commonly used for simple obfuscation and rot13.com style puzzles.

📌 ROT13 Output:
Type or paste text to see ROT13 conversion...
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Input Length
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Output Length
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Letters Changed
💡 How ROT13 works:
  • Each letter is replaced by the letter 13 positions ahead in the alphabet
  • A becomes N, B becomes O, and so on
  • Numbers and punctuation are preserved unchanged
  • ROT13 is reversible - applying it twice returns the original text
  • The same tool both encodes and decodes (symmetrical cipher)

📝 Examples:

Input (Original):
Hello World
Output (ROT13):
Uryyb Jbeyq
Input (ROT13):
Uryyb Jbeyq
Output (Original - Decoding):
Hello World
Input (With Numbers & Punctuation):
Python 3.11 is awesome!
Output (ROT13):
Clguba 3.11 vf njrfbzr!
🔤 ROT13 Alphabet Mapping:
A ↔ N
B ↔ O
C ↔ P
D ↔ Q
E ↔ R
F ↔ S
G ↔ T
H ↔ U
I ↔ V
J ↔ W
K ↔ X
L ↔ Y
M ↔ Z
📚 Use Cases:
  • Simple text obfuscation for puzzles and games
  • Hide spoilers in online discussions and forums
  • Educational tool for learning about cipher techniques
  • Rot13.com style text encoding games
  • Quick text obfuscation (not for security purposes)
  • Convert between ROT13 encoded and plain text
⚠️ Security Note: ROT13 is NOT a secure cipher and should never be used for actual security or privacy. It's only suitable for simple obfuscation and entertainment purposes. For real encryption, use proper cryptographic algorithms.