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Free ROT13 Encoder / Decoder – Rotate Letters by 13

ROT13 Encoder/Decoder rotates letters by 13 positions to encode or decode text online for free. A simple cipher that works both ways in your browser.

Encode & DecodeSame OperationReal-timeCopy ResultFree

Input (Text or ROT13)

Result

Result appears here...

100% Private

Everything runs locally in your browser. Nothing is uploaded.

How to Use ROT13 Encoder / Decoder

1

Enter Text

Type or paste the text to encode or decode.

2

See the Result

The ROT13 output updates instantly.

3

Copy the Output

Copy the result for your message or puzzle.

Encode and Decode Text with ROT13 Instantly

The Helperzy ROT13 Encoder/Decoder applies the ROT13 cipher to your text — shifting each letter by 13 positions in the alphabet. Because 13 is exactly half of 26, encoding and decoding are the same operation: apply ROT13 to the original to encrypt, apply it again to the result to get the original back. ROT13 is not secure — it is trivially broken — but it is widely used to hide spoilers, puzzle answers, and joke punchlines from casual reading. Forums, newsgroups, and puzzle communities use it so readers can choose to reveal the hidden text by decoding it. The tool updates live as you type, so you can encode a message and share the result, or paste a ROT13 string to decode it. Non-alphabetic characters like spaces, numbers, and punctuation are left unchanged. Everything runs in your browser, so it is instant, free, and works offline once loaded.

Frequently Asked Questions – ROT13 Encoder / Decoder

ROT13 shifts each letter by 13 positions in the alphabet. A becomes N, B becomes O, and so on. Because the alphabet has 26 letters, applying ROT13 twice returns the original text, so encoding and decoding are the same operation.