ROT13 Encoder/Decoder

What is ROT13?

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 the Latin alphabet has 26 letters, applying ROT13 twice returns the original text—making it both an encoder and decoder in one operation.

How ROT13 Works

The cipher shifts each letter by 13 positions:

• A → N, B → O, C → P, … M → Z
• N → A, O → B, P → C, … Z → M
• Numbers and special characters remain unchanged

Because 13 is exactly half of 26, the same operation encodes and decodes. This makes ROT13 symmetric—apply it once to encode, apply it again to decode.

Key Features

• Real-time encoding/decoding as you type
• Symmetric operation (encode = decode)
• Preserves case (uppercase stays uppercase)
• Non-letters remain unchanged
• Copy and download results
• Client-side processing for privacy

How to Use

1. Paste or type your text in the input field
2. The ROT13 transformation appears instantly in the output
3. Copy or download the result
4. To decode, simply paste the encoded text—ROT13 reverses itself!

Important Notes

• Not encryption: ROT13 is a cipher, not encryption. It provides no real security.
• Obfuscation only: Use it to hide text from casual readers, not to protect sensitive data.
• For actual security, use proper cryptographic tools like AES or RSA.

FAQs

• Is ROT13 secure?
  No. ROT13 is trivially easy to break and provides no cryptographic security. It is purely for obfuscation.
• Why use ROT13 instead of other ciphers?
  ROT13 is self-reversing, simple to implement, and widely recognized. It is commonly used in online forums to hide spoilers.
• Does ROT13 work with non-English text?
  ROT13 only transforms the 26 letters A-Z. Accented characters, Cyrillic, or other scripts pass through unchanged.
• Is my data safe?
  Yes, all processing happens in your browser. No text is sent to any server.