Advertisement
Caesar Cipher Decoder & ROT13 Tool
Free online Caesar cipher decoder and ROT13 encoder. Convert text with any shift value, encrypt messages, or decode ciphertext instantly. Works directly in your browser — secure, private, and no signup required.
ROT13 & Caesar Cipher
Free online Caesar cipher decoder and ROT13 tool. Instantly encrypt or decrypt text with any shift value. Educational cryptography tool with instant results.
ROT13 is most common (shifts by 13 places)
Caesar Cipher Information
The Caesar cipher is one of the simplest and oldest encryption techniques, named after Julius Caesar who used it to protect his military communications. With over 18,100 monthly searches for "caesar cipher", it remains a popular tool for both educational and practical applications.
How to decode a Caesar cipher:
Each letter in the ciphertext is shifted backward by the same number of positions used for encryption. Our free online Caesar cipher decoder lets you decode any message by selecting the correct shift value (or trying all 25 possible shifts if unknown).
What is ROT13?
ROT13 is a special case of the Caesar cipher with a shift of exactly 13 places. It's the most popular cipher tool with approximately 2,000 monthly searches. Since the English alphabet has 26 letters, applying ROT13 twice returns the original text, making it perfect for hiding spoilers or puzzle solutions.
Example with ROT13:
Plain: HELLO WORLD
Cipher: URYYB JBEYQ
Example with ROT3:
Plain: ATTACK AT DAWN
Cipher: DWWDFN DW GDZQ
Similar Tools
Tools for encoding and decoding data formats.
Advertisement