# CSSO

CSS minifier that cleans, compresses and restructures stylesheets, with a scoped mode for CSS modules.

STUB. This software has no release or pre-release in four years, or its project site no longer shows it, so it is not part of the register, not counted and not indexed. It will be checked again.

Source: https://findsoftware.frbit.cloud/csso/
Last reviewed: 2026-10-28
Listed since: 2026-10-28

## Record

### Links

- home: https://css.github.io/csso/csso.html
- repository: https://github.com/css/csso
- x: https://twitter.com/cssoptimizer

### Identity

- status: stub
- maintainer: Roman Dvornov
- maintainerType: unknown
- parent: unknown
- firstRelease: 2011
- hqCountry: unknown

### Kind

- category: build-tool
- hosting: not applicable
- language: javascript
- runtime: node
- runtimeMin: node 10
- basedOn: unknown

### Content

- contentStore: not applicable
- databases: not applicable
- adminUi: not applicable
- headlessApi: not applicable
- templating: not applicable
- i18n: not applicable

### Rendering and deploy

- runsAs: local
- renderingModes: not applicable
- installMethod: npm install csso

### License

- licenseModel: open-source
- license: MIT

### Releases

- currentMajor: 5
- latestReleaseDate: 2022-08-10

### Adoption

- githubStargazers: 3780
- packagistDownloads: not applicable
- npmWeeklyDownloads: 39391102
- contributors: 40
- pluginCount: unknown
- packagistMonthlyDownloads: unknown
- ecosystemsMonthlyDownloads: unknown
- httpArchiveSites: unknown
- wordpressActiveInstalls: unknown
- dependentRepos: 2739126
- dependentPackages: 982

### Sources

- urls: https://css.github.io/csso/csso.html (read 2026-10-28)
- urls: https://api.github.com/repos/css/csso (read 2026-10-28)
- maintainer: https://raw.githubusercontent.com/css/csso/master/LICENSE (read 2026-10-28)
- language: https://api.github.com/repos/css/csso (read 2026-10-28)
- category: https://raw.githubusercontent.com/css/csso/master/README.md (read 2026-10-28)
- runtime: https://raw.githubusercontent.com/css/csso/v5.0.5/package.json (read 2026-10-28)
- runtimeMin: https://raw.githubusercontent.com/css/csso/v5.0.5/package.json (read 2026-10-28)
- runsAs: https://raw.githubusercontent.com/css/csso/master/README.md (read 2026-10-28)
- installMethod: https://raw.githubusercontent.com/css/csso/master/README.md (read 2026-10-28)
- installMethod: https://raw.githubusercontent.com/css/csso/master/README.md (read 2026-10-28)
- license: https://api.github.com/repos/css/csso (read 2026-10-28)
- licenseModel: https://raw.githubusercontent.com/css/csso/master/LICENSE (read 2026-10-28)
- firstRelease: https://registry.npmjs.org/csso (read 2026-10-28)
- currentMajor: https://api.github.com/repos/css/csso/releases (read 2026-10-28)
- latestReleaseDate: https://api.github.com/repos/css/csso/releases (read 2026-10-28)
- githubStargazers: https://api.github.com/repos/css/csso (read 2026-10-28)
- contributors: https://api.github.com/repos/css/csso/contributors?per_page=1 (read 2026-10-28)
- npmWeeklyDownloads: https://api.npmjs.org/downloads/range/2026-09-28:2026-10-04/csso (read 2026-10-28)
- dependentPackages: https://packages.ecosyste.ms/api/v1/registries/npmjs.org/packages/csso (read 2026-10-28)
- dependentRepos: https://packages.ecosyste.ms/api/v1/registries/npmjs.org/packages/csso (read 2026-10-28)

## Notes

CSSO is a CSS minifier that cleans, compresses and restructures stylesheets. It is installed from npm, and its bundles can also be loaded into a web page. The optimizer is based on CSSTree, a parser that turns CSS into a syntax tree.

Usage data is an optional input. When a project supplies it, the optimizer can merge rules across scopes that never appear together on one page.

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Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Attributes are recorded, never scored; absent means unknown.
Credit, in full: FindSoftware, CC BY 4.0