# Sass

The reference implementation of Sass, written in Dart.

Repository: https://github.com/sass/dart-sass
Canonical: https://ross.abutalabs.com/products/sass
Homepage: https://sass-lang.com/dart-sass
Language: Dart
License: MIT
License Family: permissive
Topics: sass, css-preprocessor, dart, dart-sass
Last push: 2026-08-25T20:14:28+00:00
Link (homepage): https://sass-lang.com/dart-sass
Link (site_page): https://sass-lang.com/install
Link (site_page): https://sass-lang.com/documentation
Link (site_page): https://sass-lang.com/documentation/js-api

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 86, longevity 100
- inputs: {"age_days": 3593, "days_push": 8, "days_rel": 13, "gap_med": 6.0, "n_releases_24m": 65}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4216, forks 378 (observed 2026-08-28T04:08:39.212620+00:00)

## What it is
Sass is a mature CSS preprocessor language that extends CSS with variables, nested rules, mixins, functions, and selector inheritance, compiled to standard CSS. The sass/sass repository hosts the language specification and proposals, with the primary implementation being Dart Sass, distributed as a standalone CLI, a Dart library, and the pure-JavaScript sass / sass-embedded npm packages.

## Use cases
- compile scss to css
- use variables and mixins in stylesheets
- organize large css codebases with nesting and partials
- integrate sass compilation into a webpack or vite build
- programmatically compile sass from node.js or dart
- share design tokens across projects with sass functions

## When to choose
- you want a battle-tested, fully-featured CSS preprocessor with active development
- you need a fast standalone CLI or embeddable JS/Dart API for compiling stylesheets
- your project already uses .scss/.sass files and needs the reference implementation

## When to avoid
- you only need plain modern CSS, since native CSS now supports variables and nesting
- you rely on LibSass or node-sass, which are deprecated and no longer receive new features
- you want a utility-first or component-scoped styling approach rather than a preprocessor

## Facets
- artifact type: library
- maturity: stable
- function: css-framework, templating, cli, build-tool, compiler
- domain: web-development, frontend, web-design, developer-tools
- platform: cross-platform, cli
- tags: css-preprocessor, scss, sass-language, stylesheet-compilation, dart-sass, libsass-deprecated, node-sass-deprecated, nodejs, web-server, docker

## Member repositories
- sass/dart-sass (main) score 95
- sass/sass (docs) score 67
- sass/node-sass (sdk) score 10
- sass/libsass (mirror) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:39.212620+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:06:11.270209+00:00, confidence not recorded.
  - readme: https://github.com/sass/dart-sass (fetched 2026-08-28T04:08:39.212620+00:00, sha 7f6a9cffb13c)
  - homepage: https://sass-lang.com/dart-sass (fetched 2026-08-29T08:04:30.177405+00:00, sha a9c162e17286)
  - site_page: https://sass-lang.com/install (fetched 2026-08-29T08:04:30.186551+00:00, sha 50ddac124b27)
  - site_page: https://sass-lang.com/documentation (fetched 2026-08-29T08:04:30.188370+00:00, sha 62580801380c)
  - site_page: https://sass-lang.com/documentation/js-api (fetched 2026-08-29T08:04:30.190010+00:00, sha ddeface7def8)
- Data as of 2026-08-30T08:39:29.467469+00:00.