PostCSS plugin which helps you extract only used styles. Unlike uncss and others does not render your pages to find used classes, but instead parse it statically, which can be beneficial in some cases. Also support simple Angular's ng-class parsing. And also, due to awesomeness of PostCSS, it works with LESS and SCSS via PostCSS syntaxes.

<!--- HTML file -->
<div class="test"></div>

/* Input */
.test { color: #000; }
.test2 { color: #fff; }

/* Output */
.test { color: #000; }

npm i usedcss --save

Type: array of globs At least html or js option is required

HTML files to check css selector usage against them.

Type: array of globs At least html or js option is required

JS files to check css selector usage against them.

Type: array of strings

Saves ignored selectors even if they are not presented in DOM.

Type: array of regexps

Use it to save selectors based on regexp.

Type: boolean

Default: false

Parse or not to parse ng-class statements.

Type: boolean

Default: false

Ignore nesting so .class1 .class2 will be saved even if there is element with class2, but it's not nested with class1. Useful if you use templates.

Type: boolean

Default: false

Useful if you run usedcss against nested templates. It split selectors so if you have an element with class class1 in one file and an element with class class2 in another one, it will save rule with .class1 .class2 selector.

Type: boolean

Default: false

Check also for html presented in Angular's $templateCache. If you want to use this option, js option is required.

Check out PostCSS documentation on how to use PostCSS plugins.