Sites that block Claude-User
443 of the 28,868 domains we have measured, 2%, disallow claude-user at the site root in robots.txt. Claude-User fetches a page live when a user asks the assistant for it.
Every domain here has removed itself from Anthropic's answers. Blocking a retrieval agent withholds nothing from model training, because training uses a different token.
443 of 28,868 measured domains (2%) disallow claude-user at the site root in robots.txt. Every domain named on this page was fetched directly and its robots.txt parsed against RFC 9309; none of it is inferred from a third-party index.
Measured 2026-08-24 by direct request to every domain in the corpus. Method: how this is measured. Reuse under CC BY 4.0 with attribution.
Cite as: Crawl Census, "Sites that block Claude-User", measured 2026-08-24. https://crawlcensus.com/blocked/claude-user
The list 443 domains
Rank is the domain's position in the popularity list used to seed the corpus; a dash means it was scanned on request rather than seeded. Score is the site's overall AI access score, which blocking depresses but does not by itself determine.
Check a specific domain
See also the Claude-User reference, the full census, and the JSON endpoint.