ROT13 Cipher

Encode and decode ROT13 — a simple letter substitution cipher.

Free · Runs in your browser · Last updated 2026-05-03

Input

ROT13 output

About this tool

Apply the ROT13 letter-rotation cipher to any text. Symmetric: encoding and decoding are the same operation.

Privacy

All processing for ROT13 happens locally inside your browser using JavaScript. Your input is never uploaded to a server, logged, or shared with third parties.

Frequently asked questions

Is the ROT13 free to use?

Yes. ROT13 is completely free for both personal and commercial projects. There are no usage limits, no sign-up, and no premium tier.

Is my data safe when I use ROT13?

All processing happens locally in your browser using JavaScript. Your input is never uploaded to our servers, logged, or shared with any third party.

Does ROT13 work offline?

Once the page has loaded, the tool runs entirely client-side. You can disconnect from the internet and it will keep working in the same browser tab.

Which browsers are supported?

ROT13 works in all modern browsers, including the latest versions of Chrome, Firefox, Safari, Edge, Brave, and Opera, on desktop and mobile.

Do I need to install anything?

No. ROT13 runs in any modern web browser with no installation, browser extension, or account required.

More developer tools

Compare Anything

Side-by-side diff for JSON, XML, contracts, specs, job offers — with decision matrix.

JSON Formatter

Format, beautify, minify and validate JSON instantly in your browser.

XML Formatter

Pretty-print, minify and validate XML documents online.

YAML Formatter

Validate and re-emit YAML in a clean normalized form.