Best SCSS Open Source Repositories

SCSS, Sassy CSS, is a preprocessor syntax for Sass, one of the oldest and most widely used CSS extension languages. It's a superset of standard CSS, meaning any valid CSS file is also valid SCSS, but it adds features CSS itself lacked for years, like variables, nesting selectors inside one another, mixins for reusable style blocks, and functions for computing values like color adjustments. A build step compiles SCSS files down to plain CSS that browsers can actually read, since browsers have no native SCSS support.

Before CSS gained native custom properties, nesting, and other modern features, SCSS's main value was filling those gaps and helping large stylesheets stay organized as projects grew. Nesting related selectors together, for example, keeps styles for a component visually grouped in the source file rather than scattered across the file in a flat structure. Even as native CSS has closed some of this gap, SCSS remains popular for its mixins, functions, and mature tooling ecosystem, which native CSS still doesn't fully replicate.

SCSS shows up across a range of front-end and full-stack projects that predate or simply prefer its authoring style over newer utility-first approaches like Tailwind. Repos on this page using SCSS include n8n's workflow editor interface, Rocket.Chat's messaging client, Mattermost's web application, Paperless-ngx's document management interface, and Ionic Framework, a mobile UI toolkit that uses SCSS extensively for its themeable component styling system.