How do I use the ROT13 encoder?

Type or paste your text in the left panel. The ROT13-encoded output appears instantly in the right panel. Paste the output back in to decode it — ROT13 is its own inverse.

ROT13 (Rotate by 13) is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. It is self-inverse — applying ROT13 twice returns the original text. Non-letter characters are unchanged.

Is the ROT13 tool free?

Yes, completely free. Encoding and decoding run entirely in your browser — no data is sent to any server, and no signup is required.

ROT13 Encoder / Decoder

Encode or decode text with ROT13 cipher instantly online. ROT13 is self-inverse — applying it twice returns the original text. Free ROT13 tool, runs entirely in your browser.

Text Input

ROT13 Output

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How ROT13 Works

Type or paste your text in the left panel.
The ROT13-encoded output appears instantly on the right.
To decode, paste the encoded text back into the left panel — ROT13 is its own inverse.
Click Load Example to encode a sample sentence.

How It Works

Each letter is shifted 13 positions forward in the alphabet
A → N, B → O, ... Z → M (wraps around)
Numbers, spaces, and punctuation are unchanged
Applying ROT13 twice returns the original text