Claude-Web
Anthropic Claude web crawler bot
About this crawler
Claude-Web is a web crawler identified by the regular-expression pattern Claude-Web in the User-Agent request header. It is categorised as ai-crawler. Use the regex above to detect, log, allow, or block Claude-Web traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
3.5%
Technical details
- Name
- Claude-Web
- Pattern
Claude-Web- Tags
- ai-crawler
- Reference
- https://www.anthropic.com/
- Added
- 2026/04/07
- rDNS suffixes
.anthropic.com- Instances
- 1 known sample(s)
rDNS verification (FCrDNS)
Verify a request is genuinely Claude-Web with forward-confirmed reverse DNS: the client IP's PTR record must end in one of the suffixes below and a forward A/AAAA lookup of that hostname must return the same IP. UA strings alone are spoofable; FCrDNS is not.
.anthropic.com
Sample User-Agent strings
Claude-Web/1.0 (web crawler; +https://www.anthropic.com/; [email protected])
Block this crawler
robots.txt — disallow Claude-Web:
User-agent: Claude-Web
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} Claude-Web [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "Claude-Web") {
return 403;
}
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