ROT13 Cipher

What does this tool do?

This tool encodes and decodes text with ROT13, shifting every English letter 13 positions along the alphabet. Because ROT13 is symmetric, the same operation both scrambles and unscrambles text, which is why it is popular for hiding spoilers, puzzle answers, and forum jokes.

How to use it

1. Enter the text you want to encode or decode.
2. The conversion happens automatically.
3. Copy the result and use it safely.

How ROT13 works

In the 26-letter English alphabet, 13 is exactly the halfway shift. A becomes N, B becomes O, and so on, wrapping around so that N returns to A. Since 13 + 13 = 26, passing text through ROT13 twice brings you back to the original, which means a single function handles both encoding and decoding. The tool shifts only A–Z and a–z; digits, spaces, and punctuation pass through unchanged.

Where it is used

ROT13 is not real security — it has no secret key and is trivial to reverse. Its purpose is to hide text in plain sight: it stops people from accidentally reading spoilers, puzzle solutions, joke punchlines, or mild hints in forum posts. Programmers also use it as a lightweight obfuscation gag. When genuine confidentiality is needed, reach for modern encryption such as AES instead of a simple letter rotation.

Frequently asked questions