Verified Bots Directory

Directory / SEO tools

W3C CSS Validation Service

Verifiable

W3C's CSS validator, which fetches a user-submitted page and its stylesheets to check them against the CSS specifications. It runs on W3C's Jigsaw server and identifies itself with a Jigsaw prefix followed by its own W3C_CSS_Validator_JFouffa token, from the same published validator addresses.

Operated by World Wide Web Consortium (W3C) · Official documentation

User agents

Patterns this directory matches, with real observed strings.

  • regexW3C_CSS_Validator_JFouffa/[\d.]+
  • observedJigsaw/2.3.0 W3C_CSS_Validator_JFouffa/2.0

How to verify

Documented static ranges: 52.22.66.203/32, 2600:1f18:7d7a:2700::/56

IP ranges (2)

Refreshed daily from the operator's feed. Also available as /data/ips/w3c-css-validator.ips and /data/bots/w3c-css-validator.json.

2600:1f18:7d7a:2700::/56
52.22.66.203/32

Good Bot Practices scorecard

  • Identifies honestly

    Stable UA token documented (1 pattern)

  • Verifiable

    Verifiable

  • Respects robots.txt

    Does not honor robots.txt

  • Behaves

    Crawl-rate behavior is operator-declared; not machine-verifiable from this dataset

  • Reachable operator

    Operator and documentation published

Measured against the Good Bot Practices.