ROT13 Cipher

Summary

Type or paste text to instantly encode or decode it with ROT13 — the same operation works both ways.

How it works

1. Type or paste your text into the input field.
2. Each letter is shifted 13 positions forward in the alphabet (A becomes N, B becomes O, etc.).
3. Uppercase letters map to uppercase, lowercase to lowercase.
4. Numbers, spaces, and all other characters pass through unchanged.
5. The result appears instantly in the output field — apply it again to decode.
6. Use the Copy button to copy the result to your clipboard.

Use cases

• Hide spoilers in forums and comment sections without a spoiler tag.
• Obfuscate puzzle answers so readers can choose whether to reveal them.
• Decode ROT13-encoded text found in Usenet posts, Reddit comments, or old forums.
• Teach introductory cryptography concepts — ROT13 is the simplest Caesar cipher.
• Quickly scramble text for lightweight obfuscation in emails or messages.
• Verify ROT13 implementations during software testing.
• Encode punchlines in trivia games so they are not immediately visible.
• Process code strings that use ROT13 as a basic obfuscation layer.

Frequently Asked Questions