The Yagendoo System Plugin contains from version 3.0.5 a new compression for CSS & JS files, as well as the option to compress the HTML code of the frontend output. All locally loaded files are merged and compressed to one CSS and one JS file respectively. Files located outside the Joomla! header or on external servers are excluded and continue to be loaded independently.
This process results in a smaller file size and a cleaner <head> area. Both factors lead to a better loading speed and rating of the website on analysis pages such as "Google Pagespeed Insights".