# cssinjs/jss

JSS is an authoring tool for CSS which uses JavaScript as a host language.

Repository: https://github.com/cssinjs/jss
Canonical: https://ross.abutalabs.com/products/jss
Homepage: https://cssinjs.org
Language: JavaScript
License: MIT
License Family: permissive
Topics: js, css, css-in-js, cssinjs, jss, stylesheets, components
Last push: 2024-08-13T19:53:12+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4343, "days_push": 750, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 7056, forks 386 (observed 2026-08-28T04:09:55.580452+00:00)

## What it is
JSS is a library for authoring CSS style sheets using JavaScript as the host language, generating and managing styles programmatically. It is a popular css-in-js solution, but the project is no longer maintained.

## Use cases
- generate stylesheets from javascript
- css-in-js styling for react components
- dynamically compute css values at runtime
- scope styles to components without global css
- manage theme-based styling in javascript

## When to choose
- you are maintaining an existing codebase already built on JSS
- you need runtime style generation with a mature, well-documented API
- you want a framework-agnostic css-in-js library

## When to avoid
- starting a new project, since JSS is no longer maintained
- you want actively developed css-in-js alternatives like Emotion or styled-components
- you prefer static CSS or utility-first approaches like Tailwind

## Facets
- artifact type: library
- maturity: abandoned
- function: css-framework, ui-components, frontend-framework
- domain: web-development, frontend
- platform: browser, cross-platform
- tags: css-in-js, stylesheets, javascript, unmaintained, nodejs

## Member repositories
- cssinjs/jss (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:55.580452+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 2026-08-29T17:40:30.104471+00:00, confidence not recorded.
  - readme: https://github.com/cssinjs/jss (fetched 2026-08-28T04:09:55.580452+00:00, sha 4cdfb4183ab3)
  - homepage: https://cssinjs.org (fetched 2026-08-29T08:36:31.961568+00:00, sha 82143f475f89)
  - site_page: https://cssinjs.org/features (fetched 2026-08-29T08:36:31.963921+00:00, sha d9f24544d985)
  - site_page: https://cssinjs.org/faq (fetched 2026-08-29T08:36:31.965541+00:00, sha 7201021a0bd6)
- Data as of 2026-08-30T08:39:29.467469+00:00.