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. A becomes N, B becomes O, etc.

No. ROT13 is not encryption - it's simple obfuscation. It's trivially reversible and provides no security. Use it only for hiding spoilers or puzzle answers, never for sensitive data.

Since the alphabet has 26 letters, rotating by 13 twice returns to the original. Encoding and decoding use the same operation - apply ROT13 to encoded text to decode it.

ROT5 rotates digits 0-9 by 5 positions. 0 becomes 5, 1 becomes 6, etc. Combined with ROT13 for letters, it's sometimes called ROT18.

ROT47 rotates all ASCII printable characters (33-126) by 47 positions. It encodes letters, numbers, and symbols, providing more thorough obfuscation than ROT13.

ROT13 only affects A-Z and a-z letters. Accented characters, Cyrillic, Chinese, and other scripts pass through unchanged.

Usenet and forums for hiding spoilers, joke punchlines, puzzle solutions, and offensive content. Also used in some CTF challenges and programming puzzles.

Yes. Most languages have simple implementations. In Unix: echo 'text' | tr 'A-Za-z' 'N-ZA-Mn-za-m'. The Web Crypto API doesn't include ROT13 as it's not cryptographic.

Spaces, punctuation, numbers (unless ROT5 enabled), and special characters remain unchanged. Only alphabetic characters are rotated.

ROT13 has no formal standard but follows a consistent rule: shift letters by 13 positions, wrapping Z to A. It's been used since at least the 1980s on Usenet.

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Cipher Mode

Output

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Cipher Reference

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