Anthropic · Answers
Claude-User
A person asked Claude something, and Claude went to fetch your page on their behalf. The request exists only because a human generated it: no schedule, no sweep, no queue of URLs Anthropic decided to visit. That makes it the retrieval-time counterpart to Claude-SearchBot's index-time crawling, and unrelated to ClaudeBot's corpus building. Anthropic's stated reason for splitting it out at all is to give operators an independent lever over this class of traffic.
- Operated by
- Anthropic
- Purpose
- Answers
- robots.txt token
- Claude-User
- Verification
- IP verified
Fetches a page in real time to answer a question someone just asked.
How to verify Claude-User
Anthropic publishes the IP ranges Claude-User crawls from, and we fetch that list on a schedule. A request claiming to be Claude-User can therefore be checked against 26 published ranges: one that does not match is not this crawler.
Published ranges last confirmed by us on .
User agent
Anthropic has not published a full user-agent string for Claude-User. Requests are identified by the Claude-User product token appearing in the User-Agent header; we match that token rather than a whole string, because the rest of the header varies and matching it would miss real traffic.
robots.txt for Claude-User
Yes, and unqualified, which is the sharpest cross-vendor contrast in this directory. Anthropic presents robots.txt as *the* control for user-initiated requests, with no user-triggered exemption. OpenAI's structurally identical token, ChatGPT-User, says the opposite. Same behaviour, opposite promise.
Block
User-agent: Claude-User
Disallow: /Allow
User-agent: Claude-User
Allow: /robots.txt is a request, not an enforcement mechanism. It is honoured by convention, and a crawler that ignores it is stopped at your edge, not in a text file.
What blocking Claude-User costs you
Because Anthropic honours the disallow here rather than hedging it, a block actually lands, and what it stops is a fetch somebody was waiting on: retrieval of your content in response to a live user query, which Anthropic says may reduce your visibility for user-directed web search. The specific loss is a real answer about your page failing for a user who named it. Worth knowing that blocking this token is a materially stronger action than blocking ChatGPT-User, precisely because OpenAI reserves the right to ignore that rule and Anthropic does not.