Claude-User: robots token, verification and how to allow or disallow it
Claude-User is an AI crawler operated by Anthropic. Its robots.txt token is Claude-User, and the vendor documentation we fetched on 2026-09-06 is the source for every statement on this page.
| Robots token | Claude-User |
|---|---|
| Vendor | Anthropic |
| Purpose | user-initiated fetch |
| Documented verification | none published |
| Vendor documentation last verified | 2026-09-06 |
| Share of read domains disallowing it for / | 3.1% of 128 |
| Last verified |
Identity
| Robots token | Claude-User |
|---|---|
| Matched as | claude-user |
| Vendor | Anthropic |
| Purpose | user-initiated fetch |
| Documentation | https://support.claude.com/en/articles/8896518-does-anthropic-crawl-data-from-the-web-and-how-can-site-owners-block-the-crawler |
| Documented verification | none published |
Vendor text: 'When individuals ask questions to Claude, it may access websites using a Claude-User agent.' Disabling it is documented to reduce visibility for user directed web search.
Allow or disallow it
User-agent: Claude-User Allow: /
User-agent: Claude-User Disallow: /
A robots.txt rule is a request that a well behaved crawler honours. It is not an access control, and this page does not tell anyone what to choose.
Questions
Does Claude-User obey robots.txt?
The vendor documentation at https://support.claude.com/en/articles/8896518-does-anthropic-crawl-data-from-the-web-and-how-can-site-owners-block-the-crawler states that Claude-User respects robots.txt. We fetched that page and it answered our checker on 2026-09-06. This records what the vendor documents, not what any individual request did.
How do I allow Claude-User in robots.txt?
Add this group to the robots.txt at the root of the host: User-agent: Claude-User Allow: /. The token is matched case insensitively as a substring of the user agent by RFC 9309, and the longest matching rule wins.
How do I disallow Claude-User in robots.txt?
Add this group to the robots.txt at the root of the host: User-agent: Claude-User Disallow: /. A robots.txt rule is a request that a well behaved crawler honours; it is not an access control.
How do I verify a request really came from Claude-User?
We have not found a documented verification method for Claude-User: the vendor publishes neither an IP range file nor a reverse DNS convention that we could fetch. Without one, a user agent string is not evidence of origin.
What we measure
Of the 128 seeded domains whose robots.txt we have read, 4 disallow Claude-User for / and 124 allow it, which is 3.1% disallowed, week 2026-W37. Counts only: no domain is named.
The weekly AI crawler access index
Sources
| Source | Type | HTTP | Verified | Note |
|---|---|---|---|---|
| https://support.claude.com/en/articles/8896518-does-anthropic-crawl-data-from-the-web-and-how-can-site-owners-block-the-crawler | vendor | 200 | 2026-09-06 | 10 occurrences of Claude-User in the body |
| https://darkvisitors.com/agents/claude-user | aggregator | 200 | 2026-09-06 | corroboration only; volatile source: identical byte count but a different content hash on every fetch (verified twice on 2026-09-06), so the refresher compares byte counts for it, not hashes |
Free data
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AEO Watch is an independent, factual monitor. It is not affiliated with, endorsed by or speaking for any crawler vendor. Every statement is an observation with the date it was made and the raw evidence behind it: a robots.txt line, an HTTP status code, a header. There are no scores, no grades and no verdicts here, and nothing on this page is advice. A site opts out at any time and the opt out is honoured automatically and permanently.