generated: '2026-09-07'
method: searched
source: https://jigsaw.w3.org/css-validator/DOWNLOAD.html
name: css-validator
summary: >-
  The W3C CSS Validation Service is distributed as a runnable Java archive that is explicitly
  documented for command line use. It is the same engine that runs the public service, so a
  caller who needs volume, a pinned version, or offline validation runs it locally instead of
  calling jigsaw.w3.org.
official: true
publisher: W3C
repository: https://github.com/w3c/css-validator
install:
  - method: jar
    command: 'curl -LO https://github.com/w3c/css-validator/releases/latest/download/css-validator.jar'
    note: >-
      Requires a Java runtime. The link floats to the latest release, so it is not pinned —
      see packages/css-packages.yml.
  - method: source
    command: 'git clone https://github.com/w3c/css-validator && ant jar'
    note: Requires the Ant build tool. Produces css-validator.jar.
usage:
  - command: 'java -jar css-validator.jar <url>'
    description: >-
      Validate the document at a URL from the terminal. Quoted verbatim from the DOWNLOAD
      page, which gives the example `java -jar css-validator.jar http://www.w3.org/`.
    source: https://jigsaw.w3.org/css-validator/DOWNLOAD.html
flags:
  documented: false
  note: >-
    W3C documents the single invocation form above and nothing else. No flag reference is
    published for the command line mode, and none is invented here — the servlet parameters
    in conventions/css-conventions.yml are the documented request surface.
other_packagings:
  - form: war
    description: Servlet archive for Tomcat, Jetty or Jigsaw. Built with `ant war`.
    since: 2009
  - form: source
    description: Git checkout of w3c/css-validator.
caveat: >-
  The DOWNLOAD page warns that the online service runs a stable release generally older than
  the Git version, and that results and behaviour may differ between the two.