W3C Link Checker
VerifiableW3C's link checker, which follows the links on a user-submitted page to report broken and redirected references. W3C's validation services page marks it as the one validator that, being a crawling service, honors robots.txt directives, and gives the same published source addresses as the other W3C validators.
Operated by World Wide Web Consortium (W3C) · Official documentation
User agents
Patterns this directory matches, with real observed strings.
- regexW3C-checklink
- observedW3C-checklink
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-checklink.ips and /data/bots/w3c-checklink.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
Honors robots.txt (token: W3C-checklink)
- 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.