ESC

Input Text

Shifts letters by 13 positions. Encoding and decoding are the same operation.
Text is encoded in real-time as you type

Encoded / Decoded Result

All processing happens in your browser. No data is sent to any server.

Usage Examples

Hide Spoilers

Use ROT13 to hide movie, book or game spoilers in online discussions. Readers can decode when ready.

Simple Obfuscation

Obfuscate text with ROT13+5 to encode both letters and numbers for casual text hiding.

Puzzle & Cipher Games

Create cipher puzzles and decode ROT13 encoded messages for treasure hunts and puzzle games.

Features

Self-Reversing Cipher

ROT13 is its own inverse - apply it twice to get back the original text

Real-Time Encoding

Text is encoded instantly as you type, no button click needed

Multiple Cipher Modes

ROT13 for letters, ROT5 for numbers, ROT47 for all ASCII, and ROT13+5 combined

Privacy First

All processing happens locally in your browser, no data sent to servers

How to Use?

1

Choose Cipher Mode

Select a cipher mode: ROT13, ROT5, ROT47 or ROT13+5 depending on what you want to encode.

2

Enter Text

Type or paste your text. The encoded result appears instantly in real-time.

3

Copy or Swap

Copy the result to clipboard, or use Swap to move the output back to input for verification.

Frequently Asked Questions

ROT13 shifts each letter 13 positions forward in the alphabet. A becomes N, B becomes O, etc. Since the English alphabet has 26 letters, applying ROT13 twice returns the original text — the same operation encodes and decodes. Non-letter characters (spaces, punctuation, numbers) are left unchanged.

No. ROT13 is obfuscation, not encryption. Anyone who knows it is ROT13 (which is everyone) can decode it instantly. Use it for hiding spoilers in forums, obscuring puzzle answers, or casual text hiding — never for sensitive data. For actual security, use AES encryption or TLS.

ROT13 shifts only letters (A-Z, a-z) by 13 positions. ROT5 shifts only digits (0-9) by 5 positions. ROT47 shifts all printable ASCII characters (codes 33 to 126, which includes !, @, #... through ~) by 47 positions. ROT13+5 combines ROT13 for letters and ROT5 for digits simultaneously, leaving other characters unchanged.

Use ROT47 when you want to obfuscate digits and symbols in addition to letters. ROT47 encodes the full range of typeable ASCII characters, so email addresses, URLs, and numeric data all get encoded. ROT13 leaves numbers untouched, so phone numbers and dates remain readable.

Paste the encoded text into the input field and select ROT13 mode — the decoded text appears instantly. ROT13 is self-inverse: applying it to encoded text gives you back the original. There is no separate "decode" button; encoding and decoding are the same operation.

Swap moves the encoded output back into the input field. Combined with ROT13's self-inverse property, this is an easy way to verify your encoding: encode a message, hit Swap, encode again — you should get your original text back.

Hiding spoilers in forum posts and subreddits (traditional use on Usenet/Reddit). Obscuring puzzle answers so readers can choose to see them. Light obfuscation of contact info to slow naive email scrapers. Fun cipher puzzles and treasure hunts. Source code easter eggs that obscure a string from a casual glance.

No. All encoding runs locally in your browser via JavaScript. Your text never leaves your device. The page also works offline once loaded.

What is ROT13?

ROT13 is one of those classic ciphers every developer bumps into sooner or later. It shifts each letter by 13 positions in the alphabet, and since there are exactly 26 letters, applying it twice brings you right back to the original. This tool lets you encode and decode text instantly with ROT13, ROT5, ROT47, and ROT13+5 modes.

Four Cipher Modes in One Tool

ROT13 handles letters, ROT5 takes care of digits (shifting by 5), ROT47 covers all printable ASCII characters, and ROT13+5 combines letter and number rotation. Pick the mode that fits your use case - whether you are hiding a spoiler or building a puzzle game.

Common Use Cases

People use ROT13 to hide spoilers in forums and Reddit posts, create simple cipher puzzles for treasure hunts, obfuscate email addresses from basic scrapers, and teach kids about cryptography basics. It is not security - it is a fun, practical text trick.

How This Compares to Real Encryption

ROT13 is a Caesar cipher with a fixed shift of 13. It provides zero security against anyone who knows what it is (which is everyone). For actual encryption, you would use AES or similar. ROT13 is purely for casual obfuscation where the goal is to prevent accidental reading, not determined decryption.

Privacy and Browser Processing

Everything runs in your browser using JavaScript. Your text never leaves your device - no server requests, no logging, no cookies tracking what you encode. Type or paste your text and the result appears instantly.

Security and Privacy

Your data security is our priority

Local Processing

All processing happens in your browser

No Data Transfer

Your data is not sent to our servers

No Data Storage

No data is stored or shared

SSL Encryption

SSL encryption for secure connection

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