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ROT13 Decoder

Paste text you think is ROT13 and read the decoded version. A built-in check tells you whether it actually looks like ROT13.

How to decode ROT13

To decode ROT13 by hand, move each letter 13 places along the alphabet, wrapping from Z back to A. The text Uryyb becomes Hello. The decoder does this instantly for any amount of text, and leaves digits, spaces and punctuation as they are.

Is this really ROT13?

Not every scrambled text is ROT13. The check under the output compares how many common English words appear in your text and in the decoded text. If the decoded version has clearly more, the tool says your text looks like ROT13. If the original already reads as English, it tells you it may not be encoded at all. Short texts give a weak signal, so treat the check as a hint.

If the result is still gibberish

Several things can be going on:

  • The text uses a different shift, such as a Caesar cipher with another number.
  • The text is in another language, so English word counts do not help.
  • The text uses a different scheme, such as Base64 or a substitution with a keyword.

Spotting ROT13

ROT13 text keeps its word lengths, capital letters and punctuation. Common short words become other short words, such as the turning into gur and and turning into naq. Seeing those patterns is a strong clue.

Need to encode instead? Use the ROT13 encoder. For lots of lines or files, try the batch converter, and read the guide to ROT13 for background.

Frequently asked questions

What is ROT13 for the word Uryyb?

Hello. Each letter is moved 13 places along the alphabet.

How can I tell if text is ROT13?

Look for word shapes that almost read as English, or use the check on this page, which compares common English words before and after decoding.

Why does the decoded text still look wrong?

It may use a different shift or cipher, or it may be in another language.

Is decoding the same as encoding?

Yes. ROT13 is its own inverse, so one operation does both.