The program can be used to compress web page files (HTML, CSS, JS, PNG, GIF, JPEG). Configurable compression level makes you able to decide if you want faster compression speed or smaller files.
In the case of HTML files program compresses <style> <script> sections separately using appropriate algorithms. For a typical file compression is achieved at 80%. This means that an average web site can handle up to 20% more visitors at the same time.
The quality of image files is not lowered (lossless compression), and text files (CSS, JS, HTML) retain all the necessary information.
Before you remove original files you should check optimized the files, because they can not be unoptimized.