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ROT13 Encoder / Decoder

Apply the classic ROT13 letter cipher.

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This ROT13 tool rotates each letter 13 places through the alphabet, so Hello becomes Uryyb. ROT13 is its own inverse — running it twice returns the original — so a single button both encodes and decodes.

How to use ROT13

  1. Paste your text (or your ROT13 text).
  2. The rotated version appears instantly.
  3. Copy it. To decode, just run ROT13 on it again.

What is ROT13 for?

ROT13 is a classic letter-substitution cipher used online to hide text in plain sight — spoilers, quiz answers, punchlines and puzzle hints — so people can reveal it only if they choose to. Because 13 is exactly half of 26, applying it twice brings you back to the start, which is what makes one operation work both ways.

Not for security

ROT13 offers no real protection: it is trivial to reverse and has no key. Treat it as a fun way to obscure text, never as encryption for anything sensitive.

Frequently asked questions

How do I decode ROT13?

Just apply ROT13 again. The cipher is symmetric, so encoding and decoding are the same operation.

Does it change numbers and punctuation?

No. Only the 26 letters are rotated; digits, spaces and punctuation stay exactly as they are.

What is ROT47?

A variant that rotates a wider range of characters including numbers and symbols. This tool implements the classic letters-only ROT13.

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