🔐 ROT13 Text Converter

Professional ROT13 cipher converter for encoding and decoding text using the classic Caesar cipher with 13-character rotation. Perfect for simple text obfuscation, puzzles, and educational cryptography demonstrations

Enter any text to convert using ROT13 cipher. The same operation encodes and decodes - ROT13 is its own inverse.
Maintain uppercase and lowercase formatting in the output
Keep numbers, punctuation, and special characters unchanged
Display the A-Z to N-Z, A-M character conversion table
Process multiple lines separately and show individual results

ROT13 Conversion Result:

✓ ROT13 Cipher Conversion

Classic Caesar cipher with 13-character rotation

🔐 Converted Text

Uryyb Jbeyq! Guvf vf n frperg zrffntr.
Original Text: Hello World! This is a secret message.
ROT13 Properties: A → N, B → O, C → P ... N → A, O → B, P → C

How to Use This ROT13 Text Converter

How to Use the ROT13 Text Converter:

  1. Enter your text in the input field (plaintext or ROT13-encoded)
  2. Choose formatting options like case preservation and special character handling
  3. Select additional features like character mapping display or batch processing
  4. Click "Convert Text" to apply the ROT13 cipher transformation
  5. View your converted text in the results section
  6. Use the copy button to clipboard or download for offline use
  7. Apply ROT13 again to the result to get back your original text

Pro Tips: ROT13 is its own inverse - applying it twice returns the original text. Use it for simple text obfuscation, spoiler protection, or educational cryptography demonstrations. Perfect for forum posts, puzzles, and basic text encoding needs.

How It Works

ROT13 Caesar Cipher Algorithm:

ROT13 is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet:

  1. Alphabet Rotation: Each letter A-Z is shifted 13 positions forward (A becomes N, B becomes O, etc.)
  2. Wraparound Logic: Letters N-Z wrap around to the beginning (N becomes A, O becomes B, etc.)
  3. Case Preservation: Uppercase and lowercase letters are handled separately while maintaining original formatting
  4. Non-alphabetic Characters: Numbers, punctuation, and special characters remain unchanged
  5. Symmetric Property: ROT13 is its own inverse - applying it twice returns the original text
  6. Unicode Support: Handles international characters and extended ASCII properly

The cipher provides simple obfuscation suitable for spoiler protection, basic puzzles, and educational cryptography without serious security - it's easily reversible and not suitable for protecting sensitive information.

When You Might Need This

Frequently Asked Questions

Is ROT13 secure encryption for protecting sensitive data?

No, ROT13 is not secure encryption and should never be used to protect sensitive information. It's a simple substitution cipher that can be easily decoded by anyone who knows the method. ROT13 is designed for simple obfuscation, not security - use it only for spoiler protection, puzzles, and educational purposes.

Why is ROT13 its own inverse (applying it twice gives the original text)?

ROT13 shifts each letter exactly 13 positions in a 26-letter alphabet. Since 13 is exactly half of 26, shifting 13 positions twice (13 + 13 = 26) brings you back to the starting position. This mathematical property makes ROT13 self-reversing - the same operation both encodes and decodes.

Does ROT13 work with numbers and special characters?

Traditional ROT13 only transforms letters (A-Z, a-z) and leaves numbers, punctuation, spaces, and special characters unchanged. Our converter follows this standard but offers options to preserve or modify the handling of non-alphabetic characters based on your needs.

Can I use ROT13 with non-English text and international characters?

ROT13 was designed for the English alphabet (A-Z) and works best with English text. International characters, accented letters, and non-Latin alphabets are typically left unchanged. For international text encryption, consider using more sophisticated encoding methods designed for Unicode support.

What's the difference between ROT13 and other Caesar ciphers?

ROT13 is a specific type of Caesar cipher that uses a shift of 13. Other Caesar ciphers can use any shift value (1-25). The key advantage of ROT13's 13-shift is that it's self-reversing due to the mathematical properties of the 26-letter alphabet, making it uniquely convenient for simple text obfuscation.