Claude-User user agent
Operated by Anthropic
Claude-User is the user agent Claude uses when it fetches a page because a Claude user asked a question that needs it.
The Claude-User bot at a glance
- Claude-User is operated by Anthropic and fetches a page when a person asks an AI assistant about it or shares its link.
- The robots.txt token for Claude-User is Claude-User.
- Blocking an AI assistant fetcher has no effect on search rankings.
- Claude-User robots.txt support: Yes.
- Recommendation for Generative Engine Optimization (GEO): Allow.
What is Claude-User?
Claude-User visits pages on behalf of individual Claude users, for example to read a page the user referenced.
Anthropic says blocking Claude-User prevents Claude from retrieving a site’s content in response to user queries.
Should you block Claude-User?
Allow Claude-User unless it causes a measurable load problem.
| Effect on search rankings | Blocking an AI assistant fetcher has no effect on search rankings. |
|---|---|
| Effect on AI visibility | Blocking stops the assistant from reading your page when a user asks about it or pastes your link, so its answer falls back to other sources. |
| Follows robots.txt | Yes |
| Recommendation | Allow |
How to block or allow Claude-User
Put the robots.txt rule in the file at the root of every domain and subdomain, for example https://example.com/robots.txt. The token Claude-User is matched case-insensitively.
robots.txt: block
# Block Claude-User
User-agent: Claude-User
Disallow: /robots.txt: allow
# Allow Claude-User
User-agent: Claude-User
Allow: /robots.txt: partial
# Keep Claude-User out of private areas only
User-agent: Claude-User
Disallow: /wp-admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Allow: /Nginx
# Nginx: return 403 to Claude-User
if ($http_user_agent ~* "(Claude\-User)") {
return 403;
}Apache
# Apache .htaccess: return 403 to Claude-User
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (Claude\-User) [NC]
RewriteRule .* - [F,L]Cloudflare WAF
# Cloudflare > Security > WAF > Custom rule, action: Block
(http.user_agent contains "Claude-User")How to verify real Claude-User traffic
Anthropic publishes the IP ranges that Claude-User uses. A request with the Claude-User user agent from an IP outside that list is an impersonator.
How to find Claude-User in your server logs
Search the web server access log for the token. The command below counts Claude-User requests per URL on Nginx or Apache.
grep -i "Claude-User" access.log | awk '{print $7}' | sort | uniq -c | sort -rn | head -20For a full report per AI bot, upload the log to the AI Log File Analyzer, a free tool by Justin Hà.
Claude-User FAQ
Claude-User uses the robots.txt token "Claude-User". Anthropic does not publish a full user-agent string, so match the token inside the User-Agent header.
Yes. Anthropic states that Claude-User follows robots.txt rules written for the "Claude-User" token.
Blocking an AI assistant fetcher has no effect on search rankings. Blocking stops the assistant from reading your page when a user asks about it or pastes your link, so its answer falls back to other sources.
Add two lines to the robots.txt file at the root of each domain and subdomain: "User-agent: Claude-User" followed by "Disallow: /". The token is case-insensitive. Changes can take up to 24 hours to be picked up.
Yes. Anthropic publishes the IP ranges Claude-User uses. Check the request IP against that list; a matching user agent from any other IP is an impersonator.
Search your server access log for "Claude-User", for example with: grep -i "Claude-User" access.log. The AI Log File Analyzer by Justin Hà counts visits per AI bot from an uploaded log file.
Sources: Anthropic crawler documentation. Last reviewed by Justin Hà.
See which of these bots actually reach your website
The AI Log File Analyzer by Justin Hà counts visits from GPTBot, ClaudeBot, PerplexityBot and other AI crawlers in your server log, for free. The GEO Technical Package sets up robots.txt, llms.txt and crawler access for AI search.
