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ROT13 & Caesar Cipher

Rotate letters by any shift

Free forever — no sign-up, nothing uploaded. Files never leave your device.

braincoder.app/use/rot13

ROT13 & Caesar Cipher

Rotate letters by any shift

Drop your file here

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Browse files

document.pdf

1.2 MB

report.pdf

860 KB

100% private

Nothing is uploaded — everything runs in your browser.

Free forever

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Local processing

Processing time depends on your input and device.

About this tool

Apply ROT13 or any Caesar shift to text, with an optional ROT47 mode for the full printable ASCII range.

The BrainCoder ROT13 & Caesar Cipher tool applies classic letter substitution ciphers to any text. ROT13 shifts every letter by 13 positions in the alphabet — so A becomes N, B becomes O, and so on. Apply it twice and you get back the original text, making it its own inverse. The Caesar cipher extends this concept with configurable shift values from 1 to 25.

While these ciphers are not secure by modern standards, they remain useful for hiding spoilers in forum posts, obfuscating text in puzzles and games, teaching the fundamentals of cryptography, and quick text scrambling. Our tool lets you adjust the shift value dynamically and supports both uppercase and lowercase letters while preserving numbers, spaces, and punctuation.

This is a fun, educational tool that runs entirely in your browser. No data is transmitted — just enter your text, pick a shift value, and see the result instantly. It's a great starting point for anyone learning about encryption and decryption.

Key features

Everything you get with ROT13 & Caesar Cipher — no premium upsell.

ROT13 with one-click toggle

Caesar cipher with configurable shift (1-25)

Preserves case, numbers, punctuation, and whitespace

Real-time conversion as you type or adjust shift

One-click copy for output text

Client-side processing — no data leaves your browser

How to use ROT13 & Caesar Cipher

Follow the steps below to use the tool.

  1. 1

    Enter your text

    Type or paste the text you want to encrypt or decrypt into the input area. Any text works — letters, numbers, symbols, and spaces.

  2. 2

    Select cipher mode

    Choose ROT13 for the classic 13-position shift, or select the Caesar cipher and adjust the shift value slider to your desired offset (1-25).

  3. 3

    View the result

    The output updates in real time showing the encrypted (or decrypted) text. Letters are shifted; all other characters remain unchanged.

  4. 4

    Copy the output

    Click the copy button to grab the ciphered text and share it in a forum post, puzzle, or educational exercise.

Still free, still private — your files never leave your device.

Launch ROT13 & Caesar Cipher

Frequently asked questions

Quick answers before you launch the tool.