css-razor is a fast way to remove unused selectors from css. Essentially, it accomplishes the same goal as uncss. However, it accomplishes this goal differently. Rather than loading a webpage in phantomjs and using document.querySelector to determine if a selector is being used, css-razor uses cheeriojs to parse static html and css files to removed unused selectors. Below is an example of building an html file from a react app created with create-react-app. The resulting HTML file can then be used for server rendering and detecting selectors with css-razor.