generated: '2026-09-07'
method: searched
source: https://www.w3.org/Style/CSS/all-properties.en.json
name: CSS Vocabulary — properties and descriptors
description: >-
  The CSS vocabulary as published by the W3C CSS Working Group. W3C generates two
  machine-readable JSON indexes from the CSS specifications themselves and serves them
  from w3.org: every CSS property and every at-rule descriptor, each with the spec that
  defines it, the anchor URL of its definition, and the W3C maturity status of that
  definition. Both files in this directory are saved verbatim from those URLs.
publisher: W3C CSS Working Group
license: https://www.w3.org/copyright/document-license/
files:
  - file: vocabulary/css-all-properties.json
    source: https://www.w3.org/Style/CSS/all-properties.en.json
    http_status: 200
    fetched: '2026-09-07'
    bytes: 430638
    format: json
    shape: 'array of { property, url, status, title }'
    rows: 2279
    unique_terms: 731
    note: >-
      One row per (property, defining specification) pair, so a property defined in both an
      Editor's Draft and a Recommendation appears more than once. 731 distinct property names.
  - file: vocabulary/css-all-descriptors.json
    source: https://www.w3.org/Style/CSS/all-descriptors.en.json
    http_status: 200
    fetched: '2026-09-07'
    bytes: 48927
    format: json
    shape: 'array of { descriptor, URL, status, specification }'
    rows: 263
    unique_terms: 92
    note: At-rule descriptors (@font-face, @counter-style, @page, @property and others).
terms:
  properties: 731
  descriptors: 92
  defining_specifications: 101
maturity_distribution:
  note: >-
    Counted from the property rows in css-all-properties.json. These are W3C Process
    maturity levels, not CSS "levels" — see lifecycle/css-lifecycle.yml.
  ED: 1239
  WD: 555
  CRD: 163
  REC: 161
  FPWD: 96
  CR: 58
  NOTE: 7
related:
  - name: webref — machine-readable extracts of every CSS spec
    url: https://github.com/w3c/webref
    note: >-
      W3C also publishes per-specification JSON extracts (properties, values, at-rules,
      selectors) to npm as @webref/css. Recorded in packages/css-packages.yml.
  - name: CSS Snapshot 2026
    url: https://www.w3.org/TR/css-2026/
    note: The W3C definition of which CSS specifications make up "CSS" in a given year.