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ROT13 Encoder

ROT13 Encoder is part of Toolspire and is ready as soon as this page loads. ROT13 is its own inverse because the alphabet has 26 letters and 13 plus 13 is 26. It is a puzzle obfuscation, not a secret.

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On this page

What you can do here

One operation both ways

You do not pick encode or decode. A second pass restores the text.

The alphabet wraps

N is the 14th letter and lands on A.

Not encryption

The detail says so. Anyone who knows the name can undo it.

The sequence

How to use the ROT13 Encoder

  1. 1

    Type Hello

    The result should be Uryyb.

  2. 2

    Paste Uryyb back

    You should see Hello. That is the inverse check.

  3. 3

    Do not use it for a password

    It hides nothing from a person who looks.

Worth knowing

  • ROT13 Encoder on Toolspire: Hello rotates to Uryyb.
  • Uryyb rotates back to Hello. The same operation decodes.
  • Only letters move. Digits, spaces and punctuation stay.
  • Case is kept. H becomes U, and h becomes u.

Halfway around the alphabet

There are 26 letters. Shifting by 13 and shifting by 13 again returns to the start, so ROT13 does not need a separate decode mode. Hello maps to Uryyb because H is eight letters after A and U is eight letters after N. Characters outside A to Z are copied unchanged, which keeps spaces between the rotated words.

FAQ

Questions about ROT13 Encoder

Where does ROT13 Encoder run?

ROT13 Encoder runs in this tab on Toolspire. What you type or drop in is not sent to us and is not stored on a server.

What is the ROT13 of Hello?

Uryyb.

How do I decode Uryyb?

Run ROT13 again. The result is Hello.

Do numbers change?

No.

Is this a cipher I should trust?

No. It is a well-known rotation. It stops a casual glance and nothing more.

Keep going

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