CSS Optimizer – Remove Unused CSS

"Remove Unused CSS" is frequently flagged in Google's PageSpeed Insights. Indeed, most scenario, around 70% – 80% of a page's CSS codes are redundant, and can be removed without affecting the overall visual. This happens mainly because WordPress themes and plugins are created as generic solutions that includes a bunch of features that may or may not be used on a particular page.

Example: A theme may come with a bunch of features such as slider, carousel, animation and etc, but your home page may use only the slider feature and your about page may use only the carousel feature. However, for practical reason, it's virtually impossible to selectively include only the required CSS rules for the features that were enabled on a particular page.

This is where the CSS Optimizer becomes useful. The plugin make calls to ZippiSite's CSS Optimizer API to find the required CSS rules on a particular page, and remove the ones that are not needed.