CleanCSS is a powerful CSS optimizer and formatter. Basically, it takes your CSS code and makes it cleaner and more concise.
The CSS optimizer was originally developed by some awesome dudes over at CSS Tidy. They built the program and have made it free for everyone to use. I stumbled across their optimizer one day while looking for help with my CSS. I wanted to know the shortest way I could style a background of a web site without having to use all the “background-image” and “background-repeat” tags. I found some other optimizers which I tried, but none worked as well as CSS Tidy.