ClaudeBot
Anthropic · Training · robots.txt: Yes
Collects public web content that could contribute to training Anthropic's generative AI models.
Block ClaudeBot
User-agent: ClaudeBot
Disallow: /Blocking ClaudeBot tells Anthropic to exclude your site's future content from its training datasets. Search and user fetches are controlled separately by Claude-SearchBot and Claude-User.
Allow ClaudeBot
User-agent: ClaudeBot
Allow: /An allow group only changes anything if a broader rule would block ClaudeBot. Under the robots.txt standard (RFC 9309, section 2.2.1) a crawler follows the group that names it and uses the User-agent: * group only when no group does — so this group lets it in even if your * group says Disallow: /. Token matching is case-insensitive.
Put these lines in /robots.txt at the root of each host (each subdomain has its own file). robots.txt is a request to well-behaved crawlers, not access control.
Facts
- Operator
- Anthropic
- Purpose
- Model training
- Obeys robots.txt
- Yes. Anthropic says its bots honour robots.txt directives and support the non-standard Crawl-delay extension. It says blocking by IP address may not work reliably, because that stops it from reading your robots.txt.
- In your server logs
- Unconfirmed by the operator Anthropic's documentation we checked does not give its user-agent string.
- How to verify it
- Anthropic says a crawler whose source IP address is on its published list is coming from Anthropic.
Published list: claude.com/crawling/bots.json — 26 IPv4 ranges when we fetched it, list dated 18 Aug 2026. Always match against the live list; operators update them.
What Anthropic says
Quoted word for word from the operator's documentation.
“ClaudeBot helps enhance the utility and safety of our generative AI models by collecting web content that could potentially contribute to their training.”
“When a site restricts ClaudeBot access, it signals that the site's future materials should be excluded from our AI model training datasets.”
“Anthropic’s Bots respect “do not crawl” signals by honoring industry standard directives in robots.txt.”
“To limit crawling activity, we support the non-standard Crawl-delay extension to robots.txt.”
“Alternate methods like blocking IP address(es) from which Anthropic Bots operates may not work correctly or persistently guarantee an opt-out, as doing so impedes our ability to read your robots.txt file.”
“If a crawler has a source IP address on this list, it indicates that the crawler is coming from Anthropic.”
Sources
- Claude Help Center: Does Anthropic crawl data from the web, and how can site owners block the crawler? — fetched and checked 2026-09-22
- Anthropic: crawler IP ranges (bots.json) — fetched and checked 2026-09-22