🔄

ROT13 Encoder / Decoder

Apply ROT13 substitution — rotate each letter by 13 positions. Encoding and decoding are the same operation.

Input

Output

Characters: 0

Letters rotated: 0

Unchanged: 0

Show ROT13 Alphabet Mapping

About ROT13 Encoder / Decoder

Security-sensitive operations should never require uploading your data to a third-party server. ROT13 Encoder / Decoder runs entirely in your browser, letting you apply rot13 substitution — rotate each letter by 13 positions. encoding and decoding are the same operation with complete confidence that your information stays private. No server calls, no logging, no data retention.

How to Use

Enter your data Paste or type your sensitive data into the input field. Remember: nothing leaves your browser.

Configure options Select the algorithm, encoding format, key size, or other parameters as needed.

Process Click the action button to encrypt, hash, encode, or perform the security operation.

Copy the output Copy the result securely. For sensitive outputs, make sure to store them in a safe location.

🔒 Privacy note: All processing happens locally in your browser. Your data is never sent to any server.

Why Use ROT13 Encoder / Decoder?

🔒

True Client-Side Security All cryptographic operations run in your browser using the Web Crypto API. Your sensitive data — passwords, keys, encrypted messages — never touches any server.

🛡️

Industry-Standard Algorithms ROT13 Encoder / Decoder uses the same cryptographic algorithms trusted by banks, governments, and security professionals worldwide. No homebrew crypto.

👁️

Open & Transparent View the source code right in your browser (Ctrl+U). Verify exactly what the tool does with your data — no hidden behavior, no tracking.

⚡

No Registration Required Security tools should be accessible without creating accounts or sharing personal information. Use ROT13 Encoder / Decoder immediately — no sign-up, no email, no strings attached.

Frequently Asked Questions

ROT13 (rotate by 13) is a simple letter substitution cipher that replaces a letter with the letter 13 positions after it in the alphabet. A becomes N, B becomes O, and so on. Since the alphabet has 26 letters, applying ROT13 twice returns the original text.

Because 13 + 13 = 26, which is the full alphabet length. So applying ROT13 to an already ROT13-encoded text gives back the original. That's why the same "Apply ROT13" button works for both encoding and decoding.

ROT13 only affects alphabetic characters (A-Z and a-z). Numbers, spaces, punctuation, and all other characters pass through unchanged. Case is preserved — uppercase letters stay uppercase and lowercase stay lowercase.