ROT13 Encrypt/Decrypt
Online ROT13 encryption/decryption tool supporting ROT13, ROT5, ROT18, ROT47 variants with one-click conversion
ROT13 Encryption Guide
ROT13 (Rotate by 13 places) is a simple letter substitution cipher that replaces each letter with the 13th letter after it in the alphabet. Since the English alphabet has 26 letters, ROT13 is its own inverse, meaning encryption and decryption use the same operation.
What is ROT13?
ROT13 (Rotate by 13 places) is a simple letter substitution cipher that replaces each letter with the 13th letter after it in the alphabet. Since the English alphabet has 26 letters, ROT13 is its own inverse.
How It Works
For each letter, shift its position in the alphabet by 13 places. For example: A → N, B → O, ..., M → Z, N → A, O → B, ..., Z → M. Case is preserved, non-letter characters are unaffected.
ROT5 Variant
ROT5 only converts digits: 0 → 5, 1 → 6, ..., 4 → 9, 5 → 0, ..., 9 → 4. Also self-inverse, often combined with ROT13.
ROT47 Variant
ROT47 uses ASCII characters 33-126 (94 characters), replacing each character with the 47th character after it. Covers all printable ASCII characters, also self-inverse.
ROT13 Alphabet Table
Uppercase letter conversion reference:
Variant Comparison
| Variant | Range | Example |
|---|---|---|
ROT13 | A-Z, a-z | Hello → Uryyb |
ROT5 | 0-9 | 12345 → 67890 |
ROT18 | A-Z, a-z, 0-9 | ABC123 → NOP890 |
ROT47 | ASCII 33-126 | Hello! → w6==@P |
Use Cases
Hide Content
Hide spoilers, answers in forums or emails
Text Games
Simple encryption for riddles and puzzle games
Educational Demo
Cryptography introduction, demonstrating substitution cipher principles
Security Note
ROT13 is not real encryption, only suitable for entertainment