Claude-User
Anthropic · User-action fetcher
What it does
Claude-User fetches a page because a user asked about that specific link. Fetches a page on behalf of a Claude user following a link.
It does not execute JavaScript. Whatever your server returns in the initial HTML response is the entire page as far as Claude-User is concerned — if your content is rendered client-side, this crawler reads an empty container.
Should you block Claude-User?
Blocking it means that when someone pastes your URL and asks what it says, the assistant cannot read it and says so. This is the most direct visibility loss of the three.
A user who shares your link with Claude gets told the page could not be fetched. If your business involves people sharing your documentation, pricing or research with an assistant, this is a direct loss.
To allow it
User-agent: Claude-User
Allow: /To block it
User-agent: Claude-User
Disallow: /Put the rule in your robots.txt at the site root. A group that names Claude-User explicitly takes precedence over your User-agent: * group, so naming it is how you make your intent survive later edits to the wildcard rules.
Verifying a real Claude-User request
Verify against Anthropic's published IP ranges. Like other user-action fetchers, it produces sporadic single requests rather than a crawl pattern, so traffic-shape heuristics tend to misread it.
The mistake people make
Bot-protection services classifying it as an unknown automated client and serving a challenge page. The challenge is what gets read, and the answer describes your CAPTCHA rather than your product.
Anthropic's other crawlers
- ClaudeBotCollects content for Anthropic model training.
- Claude-SearchBotIndexes pages to support Claude search results.
Can Claude-User reach your site?
The free scan parses your robots.txt, evaluates every AI crawler against it, and tells you how much of a page Claude-User would actually come away with.
Run the free scan