ROT13 Converter — Free Online Tool
Last updated: January 2025
What is ROT13 Converter?
ROT13 Converter shifts each letter 13 positions in the alphabet — the same operation encodes and decodes.
When to use ROT13 Converter?
Use it for spoiler-hiding in forum posts, simple text obfuscation, puzzle answers, and learning about Caesar ciphers.
How to use this tool
- 1Paste your text
- 2Click 'Convert' (works for both encoding and decoding)
- 3Copy the ROT13 output
Examples
| Input | Output |
|---|---|
| Hello World | Uryyb Jbeyq |
| Uryyb Jbeyq | Hello World (decoded) |
| ROT13 is fun | EBG13 vf sha |
| ABCDEFGHIJKLM | NOPQRSTUVWXYZ |
| Spoiler: character dies | Fcbvyre: punenpgre qvrf |
Rules & Behavior
- Each letter shifts 13 positions in the alphabet
- Applying ROT13 twice returns the original text
- Numbers, spaces, and symbols are unchanged
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Frequently Asked Questions
What is ROT13?
ROT13 is a simple substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. A→N, B→O, etc. Since there are 26 letters, applying ROT13 twice returns the original text.
Is ROT13 the same as decoding and encoding?
Yes! Because the alphabet has 26 letters, the same ROT13 operation both encodes and decodes. Click once to encode, click again (on the output) to decode.
Is ROT13 a form of encryption?
No. ROT13 is a simple substitution cipher with no key. It provides no real security — it's used for text obfuscation (like hiding spoilers) not for protecting information.
Where is ROT13 commonly used?
ROT13 was historically used in Usenet newsgroups to hide spoilers, offensive content, and puzzle answers. It's still used in some forums and online communities.
Can I use ROT13 for passwords?
No, ROT13 is trivially reversible and provides zero security for passwords. Use proper password hashing (bcrypt, Argon2) for password security.