A Caesar cipher is one of the oldest and most widely known encryption techniques. It's a type of substitution cipher in which each letter is replaced by a different letter a set number of positions away in the alphabet. For example, with a right shift of 3, "D" becomes "G", and "L" becomes "O".

Below, you can enter text that you want to encrypt using the Caesar cipher and then the shift that you want to apply. To apply a right shift, enter a positive number; to apply a left shift, enter a negative number. The number that you enter can be greater than 26 to cycle through the alphabet more than once.