Apply the ROT13 substitution to the text

For a technical exchange, a coding lesson or a conversion check, this gives learners and developers a readable result. Apply the ROT13 substitution to the text.

Apply the ROT13 substitution to the text. The result appears instantly in your browser, ready to copy, with no account, upload or storage involved.

How to use

Paste or type the text you want to transform into the input field.
Make sure the ROT13 mode is selected if you only want letters shifted.
Click the transform button to apply the substitution.
Read the result in the output field and copy it if needed.

Example

For example, with a short phrase such as Hello, this is a ROT13 test, the tool instantly shows a shifted version. Compare the letters in the result with the input to confirm that each alphabetic character was changed, then reuse the transformed text in your exercise or message.

Input

Hello, this is a ROT13 test.

Output

Uryyb, guvf vf n EBG13 grfg.

Limits and formats

ROT13 is not strong encryption: anyone who knows the method can recover the original text.
Digits, spaces and punctuation are not changed by the classic ROT13 mode.
Other variants such as ROT5, ROT18 or ROT47 affect different characters, so check which mode is active.
Always proofread the output before relying on it, since a copy error can alter the message.

Where processing happens

Everything runs in your browser. The text you paste stays on your device and is not sent to any external service. You can test a sentence or a file without creating an account or waiting for remote processing.

Frequently asked questions

Can ROT13 protect a password?

No. ROT13 is a simple reversible substitution. It is useful for light obfuscation, classroom exercises or preventing accidental reading. For sensitive data, use proper encryption and never share an exposed secret through a weak method.

What happens if I apply ROT13 twice?

Because the substitution shifts letters by thirteen places, applying it a second time returns the text to its original state. This is handy for checking a result: transform the output again and compare it with the input you started with.

Can I import a text file?

Yes, the tool accepts several text formats and common files such as CSV, JSON, Markdown, XML or YAML. The imported content is processed in your browser. Still, avoid importing anything you would not want to handle in an online tool.