Key point. Claude-User is Anthropic's AI user fetcher. It fetches a page when a person asks the assistant to look at it; it is not an automatic crawler. It follows robots.txt.
Claude-User at a glance
These are the facts our registry holds for Claude-User, checked against Anthropic's documentation on October 14, 2026.
| Vendor | Anthropic |
| Used by | Claude's web search |
| Purpose | AI user fetch |
| Type | User agent |
| Follows robots.txt | Yes; source: community ai.robots.txt list (commit 9ad8a47e) |
| Vendor documentation | Anthropic crawler page, checked October 14, 2026 |
| Published IP ranges | claude.com/crawling/bots.json |
What is Claude-User?
Claude-User is Anthropic's AI user fetcher. It fetches a page when a person asks the assistant to look at it; it is not an automatic crawler.
In Anthropic's own words (Anthropic's crawler documentation, read October 14, 2026):
- “When individuals ask questions to Claude, it may access websites using a Claude-User agent.”
- “Disabling Claude-User on your site prevents our system from retrieving your content in response to a user query, which may reduce your site's visibility for user-directed web search.”
Anthropic uses other names for other jobs: Claude-SearchBot (AI search); ClaudeBot (AI training); anthropic-ai (other). Each takes its own robots.txt group.
Does Claude-User follow robots.txt?
Yes, Claude-User follows robots.txt: our registry records this from the community ai.robots.txt list (commit 9ad8a47e).
What Anthropic says (Anthropic's crawler documentation, read October 14, 2026):
- “Anthropic’s Bots respect “do not crawl” signals by honoring industry standard directives in robots.txt.”
A robots.txt rule records your request. It does not prove a crawler honours it, and firewall or CDN bot settings can refuse a crawler that robots.txt allows, so check those too.
How do I block Claude-User in robots.txt?
Add a group that names Claude-User and disallows the whole site:
User-agent: Claude-User
Disallow: /To keep it out of one folder only, disallow that path instead, for example Disallow: /private/.
How do I allow Claude-User?
Claude-User is allowed by default: if no group names it and no User-agent: * rule blocks it, it may read every page. A crawler obeys the most specific group that names it and falls back to User-agent: * only when no group names it (RFC 9309), so if a catch-all rule blocks crawlers, add a group for it:
User-agent: Claude-User
Allow: /How can I tell if a request really comes from Claude-User?
Match the request's IP address against Anthropic's published list, because user agents can be faked: https://claude.com/crawling/bots.json.
How often do startup websites block Claude-User?
Our AI Crawler Access Report read the robots.txt files of 600 sampled startup websites on October 7, 2026. This is its row for Claude-User, across the 569 sites whose answer it could read:
| Crawler | Type | Blocked on at least one path | Blocked on all six paths | Named in the file |
|---|---|---|---|---|
| Claude-User | AI user fetch | 3 of 569 sites (0.5%; 95% interval 0.2% to 1.5%) | 0 of 569 sites (0%; 95% interval 0% to 0.7%) | 42 of 569 sites (7.4%; 95% interval 5.5% to 9.8%) |
“Blocked” means the file disallows the crawler on at least one of six common paths (/, /pricing, /blog/, /docs/, /about, /product).
The report's headline figure, for the three AI search crawlers it tracked: “3 of 569 startup websites (0.5%; 95% interval 0.2% to 1.5%) block at least one AI search crawler (Elementera AI Crawler Access Report, October 2026).”
The figures describe that sample of Y Combinator-backed software companies on the day we fetched it. The method, the intervals and the full table are in the AI Crawler Access Report.
What the AI Crawler Access Report adds about Claude-User:
ClaudeBot is Anthropic's training crawler; Claude-SearchBot indexes pages for search in Claude. Anthropic says disabling Claude-SearchBot may reduce a site's visibility and accuracy in user search results. A third name, Claude-User, fetches a page when a person asks Claude to read it. Each takes its own robots.txt group.
5 of 569 sites (0.9%; 95% interval 0.4% to 2.0%) block at least one of the fetchers that visit a page when a person asks an assistant to read it (ChatGPT-User, Claude-User, Perplexity-User, Meta-ExternalFetcher).
How do I check whether my robots.txt blocks Claude-User?
Paste your robots.txt into our free checker and it shows, crawler by crawler, whether Claude-User may read the path you choose. Nothing you paste leaves the page.