ToolNova

🔡 ROT13 — encode & decode

Apply the classic ROT13 cipher to obscure spoilers and puzzle answers — encoding and decoding are the same operation.

Encoding Free · no sign-up Added 2026-08-02
Input
Result

Private by design. This tool runs entirely in your browser — nothing you enter or add is uploaded to any server.

How it works

  1. Paste or type your text into the input box.
  2. Choose "Encode to ROT13" or "Decode from ROT13" — the result appears instantly in the output box.
  3. Copy the result with one click. Unicode and emoji are fully supported.
  4. Everything runs locally in your browser, so even sensitive strings never leave your device.

Examples

  • Encoding "Hello, world! Try me." produces "Uryyb, jbeyq! Gel zr.".
  • Decoding "Uryyb, jbeyq! Gel zr." returns the original "Hello, world! Try me.".
  • Errors are caught and explained — paste a broken value and the tool tells you what is wrong with it.

Frequently asked questions

What is ROT13 encoding?

ROT13 shifts every letter 13 places through the alphabet. Applying it twice returns the original text, which makes it a classic way to obscure spoilers and puzzle answers.

Is my text or data uploaded to a server?

No. The ROT13 Encoder / Decoder runs entirely in your browser using JavaScript — nothing you type or paste is sent anywhere, and everything disappears when you close the tab.

Is this tool free to use?

Yes, completely free with no sign-up, no watermarks and no usage limits. ROT13 Encoder / Decoder is part of a collection of free tools where new tools are added after review.

Does it work on phones and tablets?

Yes. The layout is fully responsive and all processing is done on your device, so it works on any modern phone, tablet or computer — even offline once the page has loaded.

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