Anthropic runs it as an answer engine, which means it builds the index an assistant searches when somebody asks it a question. If your page is in that index you can be cited, quoted and linked in the answer. If it is not, you are not ranked lower — you are absent from the answer entirely, and no report anywhere will tell you so.
What blocking it costs you: You will not be cited in Claude web search answers. You disappear from that assistant’s answers. Not ranked lower — absent, with no message anywhere telling you it happened.
The user agent, and the token a rule matches on
These are two different strings and confusing them is why a rule that looks right does nothing.
A robots.txt rule matches on the product token, case-insensitively, and
ignores the rest of the user-agent header entirely.
robots.txt token
Claude-SearchBot
Operator
Anthropic
Category
Answer engine
Full user agent
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Claude-SearchBot/1.0; +Claude-SearchBot@anthropic.com)
Allowing Claude-SearchBot
Paste this into robots.txt at the root of your domain.
An empty Disallow: and Allow: / mean the same thing to a crawler. What does
not mean the same thing is having no rule at all: absence is permission by default, but it is
permission nobody wrote down, and it survives only until somebody adds a blanket
User-agent: * block without thinking about this crawler.
Blocking Claude-SearchBot
User-agent: Claude-SearchBot
Disallow: /
Before you paste that: you will not be cited in Claude web search answers. That is the cost, and it is paid silently — no error appears in your logs, no report tells you, and the traffic you lose was traffic you never saw arrive.
How the web actually treats Claude-SearchBot
Measured on 2026-09-06, by reading the robots.txt of
292 public websites and resolving each one against this crawler specifically.
Verdict
Sites
Share
Blocked
26
9%
Explicitly allowed
212
73%
No rule either way
54
18%
No site is named, here or anywhere else on this domain. The count is the useful part; a league table of
businesses that never asked to be measured is not.
The row worth reading twice is the last one. 54 of 292 sites have written no rule about
Claude-SearchBot at all, which means their position on it is an accident rather than a decision — whatever
their User-agent: * block happens to say.
What Claude-SearchBot is not
Anthropic runs 3 other crawlers with
different jobs, and this is where the expensive mistake happens.
Somebody means “do not train on my content”, writes one rule against the operator’s name as they
remember it, and blocks the crawler that would have sent them a customer instead.
Collects content for model training. Blocking it is a legitimate business choice with no traffic cost.
Rules are matched per token. Blocking one of these says nothing about the others, which is the point:
you can refuse training and keep every crawler that puts your link in front of a person.
Checking what your site does right now
Reading your own robots.txt is not the same as knowing what a crawler concludes from it.
Precedence between a User-agent: * group and a named one, the longest-match rule between
overlapping paths, and a token you spelled slightly wrong all produce a file that looks correct and
behaves otherwise.
npx axray-cli your-site.com
The scan resolves your file against all 54 crawlers on this list individually and reports
which ones are allowed, blocked, or covered by nothing. It is free, needs no account, and installs nothing.
Questions people ask about Claude-SearchBot
What is Claude-SearchBot?
Claude-SearchBot is an answer engine operated by Anthropic: it builds the index an assistant searches when somebody asks it a question. If your page is in that index you can be cited, quoted and linked in the answer. If it is not, you are not ranked lower — you are absent from the answer entirely, and no report anywhere will tell you so.
Should I block Claude-SearchBot in robots.txt?
Only if you are willing to pay what it costs. You will not be cited in Claude web search answers. You disappear from that assistant’s answers. Not ranked lower — absent, with no message anywhere telling you it happened.
What is the Claude-SearchBot user agent string?
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Claude-SearchBot/1.0; +Claude-SearchBot@anthropic.com) — and the robots.txt product token, which is what a rule actually matches on, is Claude-SearchBot.
How do I check whether my site is blocking Claude-SearchBot right now?
Scan your site with AXRAY. It resolves your robots.txt against 54 named AI crawlers individually rather than reporting one verdict for all of them, so it will tell you whether this specific crawler is allowed, blocked, or covered by no rule at all. It is free and needs no account.