ROT13 Transformation

Apply or remove the ROT13 cipher (Rotate 13) to your text instantly

Your Text

Transformed Result

A ↔ N Shift 13

0 Chars Changed

Rotate letters by 13 places, forward or back

ROT13 is one of the oldest and simplest text-scrambling tricks. Every letter is replaced by the letter thirteen places further along the alphabet, so A becomes N, B becomes O, and N goes back around to A. Because the English alphabet has 26 letters, applying ROT13 twice returns the original text. That is why a single button on this page both encodes and decodes: paste in scrambled text and you get the readable version, paste in readable text and you get the scrambled one.

Using the rotation tool

Type or paste your text into the Your Text box.
Click Rotate Text.
The Transformed Result box shows the rotated version. Beneath it, the Chars Changed figure tells you how many letters were rotated, and a small A to N label reminds you of the shift of 13.
Click Copy Result to copy the output.

Editing the input hides the previous result, so you will always copy output that matches what is in the box. To decode a message, just run it through the same button again.

What gets changed and what does not

Only the 52 basic Latin letters, uppercase and lowercase, are rotated, and the case is preserved. Digits, spaces, punctuation, accented letters such as e with an acute accent, and characters from other scripts pass through unchanged. This means the Chars Changed count covers letters only, and a message written in Cyrillic, Greek or Chinese will come back exactly as you entered it.

When ROT13 is actually useful

Hiding a spoiler or a punchline in a forum post so readers must choose to decode it.
Posting a puzzle answer or a geocache hint that should not be seen at a glance.
Obscuring an email address in plain text just enough to get past casual scrapers.
Teaching the idea of a Caesar cipher before moving on to keys and modern cryptography.

Important limitation

ROT13 offers no real security. There is no key, the method is public, and anyone can undo it instantly, including with this same tool. Never use it for passwords, personal data or anything confidential. Treat it as a way to prevent accidental reading, not deliberate reading. Processing happens in your browser using JavaScript, and there is no option here to choose a different shift amount.

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Frequently Asked Questions

How do I decode ROT13 text?

Paste the scrambled text into the box and click Rotate Text again. ROT13 is its own inverse, since rotating by 13 twice equals 26, a full trip around the alphabet, so the same operation both encodes and decodes.

Does ROT13 change numbers or punctuation?

No. Only the letters A to Z, in upper and lower case, are rotated. Digits, spaces, punctuation marks, and any characters outside the basic Latin alphabet, such as accented or non-English letters, remain unchanged in the output.

Is ROT13 a secure way to protect information?

No. It has no key and can be reversed by anyone in a second. It is meant for casual obscuring, like spoilers or puzzle hints, not for protecting passwords, personal details, or any sensitive content.

Can I change the shift amount?

Not on this page. The shift is fixed at 13, which is what makes the operation reversible with a single button. A tool that supports other shifts would be a general Caesar cipher tool instead.

What does the Chars Changed number mean?

It counts how many letters in your input were rotated. Spaces, digits, and punctuation are not counted, so a sentence with 40 letters and several spaces will show 40, regardless of the total length of the text.