Caesar Cipher Encoder Decoder Online
A powerful tool to encrypt, decrypt, and analyze Caesar ciphers with advanced features including ROT13 and brute-force analysis.
Encoding Mode - Convert Plain Text to Cipher Text
Characters: 0
Output will appear here...
About the Caesar Cipher & Cryptanalysis
What is a Caesar Cipher?
The Caesar cipher is one of the earliest known forms of encryption. It's a substitution cipher where each letter in the plaintext is "shifted" a certain number of places down the alphabet. For instance, with a shift of 3, 'A' becomes 'D', 'B' becomes 'E', and the alphabet wraps around so 'Z' becomes 'C'.
What is ROT13?
ROT13 ("rotate by 13 places") is a special case of the Caesar cipher with a fixed shift of 13. Because the English alphabet has 26 letters, applying ROT13 twice to a piece of text will restore it to its original form, making it a convenient way to hide spoilers or jokes.
Brute-Force Analysis
The Caesar cipher is considered cryptographically weak because it can be easily broken using a technique called "brute-force attack". Since there are only 25 possible shifts, an attacker can simply try every key and check the results for coherent text. Our "Brute Force" feature automates this process.
Features of this Tool
- •Clear Mode Selection: Separate tabs for encoding and decoding operations.
- •Live Processing: Instantly see results as you type.
- •ROT13 Preset: Apply the common shift of 13 with one click.
- •Brute-Force Analyzer: Automatically decrypt messages by trying all possible keys.
- •Case & Symbol Preservation: Non-alphabetic characters are ignored, and letter case is maintained.