Caesar and Vigenere ciphers are algorithms that encode and decode messages. For Caesar, each letter in a message is shifted a number amount of places down the alphabet. Vigenere is a more complex version of Caesar where the shift key is not a number, but a word. It functions using an interlaced alphabet. Here is a picture of the Vigenere table.

To start, select which cipher to use and choose encrypt. The shift key for Caesar must be a number, and the shift key for Vigenere must be a word. When entering the message, make sure it does not contain spaces, symbols, or numbers. After clicking submit, the encoded message will show on the right.

Now that you have the encoded message, you can decode it by selecting decrypt and entering the encoded message in the text input. Make sure to use the same cipher and shift key you used originally. The original message will show on the right after clicking submit. Feel free to play around with it using different ciphers and shift keys.