Claude-User

What is Claude-User?

Claude-User is the user agent identifier for Anthropic's Claude AI assistant when it accesses web content through its web browsing capability. Created and operated by Anthropic, Claude is an AI assistant designed to be helpful, harmless, and honest. The Claude-User agent was introduced with Claude's web browsing capabilities, enabling Claude to access and retrieve information from the internet when requested by human users.

Technically classified as an AI-powered web retrieval tool rather than a traditional web crawler, Claude-User functions differently from search engine indexing bots. When a human asks Claude a question that requires current information, Claude may use its browsing capability to search for and access relevant web pages to provide up-to-date information. In server logs, it identifies itself with the user agent string Claude-User, sometimes followed by additional version information.

Claude-User's behavior is distinctive because it doesn't systematically crawl websites for indexing purposes. Instead, it selectively visits pages based on specific user queries, much like a human using a web browser, but automated through AI direction.

Why is Claude-User crawling my site?

Claude-User visits websites only when directed by a human user's query. It's not continuously crawling the web or building an index. If you see Claude-User in your logs, it means someone likely asked Claude a question where your website contained relevant information.

The content Claude-User typically looks for depends entirely on what users are asking. This could range from factual information, news, product details, or specialized knowledge in your website's domain. Its visits are sporadic and query-driven rather than scheduled or systematic.

Claude-User's crawling is generally considered authorized as it accesses publicly available web pages just as a normal user would. The frequency of visits correlates directly with how often users ask Claude questions that lead to your website as a relevant source.

What is the purpose of Claude-User?

Claude-User exists to enable Claude AI to retrieve current information from the web to answer human queries accurately. Unlike search engine crawlers that build comprehensive indexes, Claude-User accesses specific web content on-demand to supplement Claude's training data with up-to-date information.

The data collected is used exclusively to answer the current user's query and is not permanently stored or used to train Claude's models. This browsing capability allows Claude to discuss recent events, access current data, and provide information that wasn't available during its training.

For website owners, Claude-User represents a new channel through which your content may reach audiences. When Claude cites information from your website, it typically provides attribution and may direct users to visit your site for more information, potentially driving traffic and exposure.

How do I block Claude-User?

If you prefer that Claude not access your website content, you can use the standard robots.txt file to control access. Claude respects robots.txt directives and will honor your preferences. To block Claude-User specifically, add the following to your robots.txt file:

User-agent: Claude-User
Disallow: /

This will instruct Claude not to access any pages on your site. If you want to block access to specific sections while allowing access to others, you can specify particular paths:

User-agent: Claude-User
Disallow: /private/
Disallow: /members-only/
Allow: /

Blocking Claude-User may prevent your content from being referenced when users ask Claude questions related to your site's topic. However, it won't affect your site's appearance in traditional search engines, as Claude doesn't influence search rankings.

If you operate a commercial website, consider that allowing Claude-User may increase visibility as Claude can direct users to your site for more information or to make purchases based on their queries. For sites with sensitive or proprietary information, blocking may be appropriate to ensure AI systems don't reproduce your content without proper context.