ROT13 Encoder/Decoder
Encode and decode text using the ROT13 cipher - a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet.
About ROT13 Cipher
ROT13 ("rotate by 13 places") is a simple letter substitution cipher that replaces each letter with the letter 13 positions after it in the alphabet. It's a special case of the Caesar cipher with a shift of 13. Because there are 26 letters in the English alphabet, ROT13 is its own inverse - applying ROT13 twice returns the original text. This means the same operation both encodes and decodes text.
ROT13 is not intended for security purposes as it provides no cryptographic security. Instead, it's commonly used to obscure text (like spoilers, puzzle solutions, or offensive content) so it's not immediately readable, while still being trivially easy to decode. It's widely used in online forums, newsgroups, and geocaching. Warning: ROT13 should never be used to protect sensitive information.
Examples:
- "Hello" →
Uryyb - "ROT13" →
EBG13 - "A" →
N, "Z" →M
Features of ROT13 Encoder
- Bidirectional: Same operation encodes and decodes
- Instant Results: Real-time transformation as you type
- Preserves Case: Maintains uppercase and lowercase
- Non-Letters Unchanged: Numbers and symbols remain as-is
- Copy & Download: Save transformed text easily
- Privacy: All processing happens in your browser
How to Use ROT13 Encoder
- Enter or paste your text into the input field
- Click "Encode/Decode ROT13" to transform the text
- The same button works for both encoding and decoding
- Copy the result or download it as a text file
Common Use Cases
- Spoiler Protection: Hide plot twists and endings in discussions
- Puzzle Solutions: Obscure answers to riddles and puzzles
- Geocaching: Encode hints and coordinates
- Forum Posts: Hide potentially offensive content
- Learning: Understand basic cipher concepts
- Fun Messages: Send simple encoded messages to friends
ROT13 Transformation Examples
- A becomes N
- B becomes O
- M becomes Z
- N becomes A
- Z becomes M
- "Hello" becomes "Uryyb"
- "ROT13" becomes "EBG13"
Important Note
Not for Security: ROT13 provides no cryptographic security and should never be used to protect sensitive information. Anyone can easily decode ROT13 text. It's designed only for obscuring text to prevent accidental reading, not for actual encryption or security purposes.