---
title: Documentation
introduction: >
  Sass is a stylesheet language that’s compiled to CSS. It allows you to use
  [variables](/documentation/variables), [nested
  rules](/documentation/style-rules#nesting),
  [mixins](/documentation/at-rules/mixin),
  [functions](/documentation/functions), and more, all with a fully
  CSS-compatible syntax. Sass helps keep large stylesheets well-organized and
  makes it easy to share design within and across projects.
---

* If you're looking for an introduction to Sass, check out [the
  tutorial](/guide).

* If you want to look up a built-in Sass function, look no further than [the
  function reference](/documentation/functions).

* If you're calling Sass from JavaScript, you may want the [JS API
  documentation][js].

* Or the [Dart API documentation][dart] if you're calling it from Dart.

* Otherwise, use the table of contents for the language reference!

[js]: https://github.com/sass/node-sass#usage
[dart]: https://pub.dartlang.org/documentation/sass/latest/sass/sass-library.html