Encoder/Decoder ROT13 Online

Use this free ROT13 decoder and encoder to convert text using the ROT13 cipher — a simple letter rotation system that shifts each letter 13 positions through the alphabet. Fast, accurate, and 100% client-side.

Text → ROT13

Encode text to ROT13

ROT13 → Text

Decode ROT13 to text

Text Input

Enter text to encode

0 chars

0 words

0 letters

ROT13 Output

Encoded ROT13 text

0 chars

0 words

0 letters

Try Sample Texts

Click on a sample to load it into the input field

Online ROT13 Decoder – How to Decode ROT13 Text

This online ROT13 decoder lets you paste any ROT13 text and instantly convert it back to readable text. You can also switch direction and use the same tool as a ROT13 encoder to create your own encoded messages.

What Is ROT13? (Meaning, Definition & Use Cases)

ROT13 ("rotate by 13 places") is a simple, classic letter substitution cipher from the Caesar cipher family. It replaces each letter with the one 13 positions later in the alphabet, wrapping around at the end. Because the English alphabet has 26 letters, ROT13 is self-inverse:

Apply ROT13 twice → you get the original text back.

This makes it a popular tool for:

•Obfuscating text (e.g., spoilers, puzzles, hidden messages)
•Simple, reversible message encoding
•Educational cryptography examples
•Fun text transformations in forums and chats
•Encoding jokes, quizzes, Easter eggs, and game hints

Although ROT13 is not a secure form of encryption, it remains one of the most recognizable and widely used lightweight ciphers on the internet.

How ROT13 Works (Step-by-Step)

1. Identify each letter in your text

Only letters A–Z and a–z are shifted.

2. Shift the letter 13 positions forward

For example:

A → N
B → O
C → P
…
M → Z
N → A
O → B
…
Z → M

3. Wrap around the alphabet

If the shift goes past Z, it continues from A.

4. Keep all non-letters unchanged

Numbers, punctuation, emojis, accents, and other Unicode characters remain the same.

ROT13 Examples (With Explanations)

Basic example

Hello → Uryyb

Uryyb → Hello

With punctuation

Hello, World! → Uryyb, Jbeyq!

With numbers

Test 123 → Grfg 123

Mixed symbols

Café @ 2025 → Pnsr @ 2025

Symmetry check

Applying ROT13 twice returns the original text:

ROT13(ROT13(text)) = text

Why Use This ROT13 Encoder/Decoder?

•
100% client-side – No data is sent to a server. Everything happens in your browser.
•
Fast & instant – Encode or decode ROT13 text immediately, with zero delay.
•
Free & unlimited – Use the tool as often as you like — no account required.
•
Accurate & Unicode-safe – Modern characters, emojis, and non-Latin text are preserved.
•
Educational – A great demonstration of Caesar ciphers, substitution ciphers, and reversible transformations.
•
Symmetric operation – One function handles both encode and decode, because ROT13 is the same transformation in both directions.

Where Does the Name ROT13 Come From?

The name ROT13 is not an acronym. It simply means:

•ROT = ROT = rotate
•13 = 13 = number of positions shifted

It belongs to the broader family of ROT ciphers, such as ROT1, ROT5, ROT47, and ROT18 — but ROT13 became the most iconic because of its perfect symmetry (26 ÷ 2 = 13).

Is ROT13 Secure?

No. ROT13 is not encryption and should never be used for sensitive information.

However, it is excellent for:

•Hiding spoilers
•Obscuring puzzle answers
•Light obfuscation
•Encoding jokes and secret text in blogs or code comments

For real encryption, you should use modern algorithms like AES-256, RSA, or secure hashing — not ROT13.

Frequently Asked Questions (FAQ)

How do I use this ROT13 decoder?

Type or paste your ROT13 text into the input, make sure the direction is set to "ROT13 → Text", and click Decode. The decoded text appears instantly in the output area.

Is ROT13 reversible?

Yes. Applying ROT13 twice restores the original text.

What is ROT13 used for?

ROT13 is mainly used for spoilers, puzzles, online forums, cryptography education, and simple text obfuscation.

Does ROT13 affect numbers or emojis?

No. Only A–Z letters are rotated; everything else remains unchanged.

Is ROT13 the same as a Caesar cipher?

Yes. ROT13 is a special case of the Caesar cipher with a rotation of 13.

Can ROT13 encrypt passwords or sensitive data?

No. ROT13 is not secure and should never be used for real encryption or passwords.

Does ROT13 work for languages like Hindi, Japanese, or German?

ROT13 only works for languages that use the standard 26-letter Latin alphabet. It does not apply to scripts like Hindi (Devanagari), Japanese (Hiragana, Katakana, Kanji), Chinese, Arabic, or other non-Latin writing systems. These characters are left unchanged. ROT13 partially works for German: it correctly rotates A–Z, but characters like Ä, Ö, Ü, and ß do not have defined ROT13 equivalents and remain unchanged. Accented letters in other Latin-based languages behave the same way.