What Is Netcraft?

Netcraft is a web crawler that conducts comprehensive internet surveys, analyzing web server technologies and infrastructure across millions of websites to provide market intelligence. You can see how often Netcraft visits your website by setting up Dark Visitors Agent Analytics.

Agent Type

Expected Behavior

Intelligence gatherers crawl websites to collect business intelligence, competitive data, and market insights on behalf of their clients. These tools may use artificial intelligence to identify and extract information like pricing changes, product listings, brand mentions, or trademark usage. Crawl patterns are highly variable. Sites relevant to a client's monitoring goals may be visited frequently (daily or hourly), while others may never be crawled. They typically focus on specific pages or data points rather than comprehensive site crawls.

Detail

User Agent String

Robots.txt

In this example, all pages are blocked. You can customize which pages are off-limits by swapping out / for a different disallowed path.

User-agent: Netcraft # https://darkvisitors.com/agents/netcraft
Disallow: /

Frequently Asked Questions About Netcraft

Should I Block Netcraft?

It depends on the use case. Intelligence gathering can range from legitimate market research to competitive data harvesting. If you benefit from similar services or the gathering seems reasonable, allow access. Block it if the activity appears excessive or solely benefits competitors.

How Do I Block Netcraft?

If you want to, you can block or limit Netcraft's access by configuring user agent token rules in your robots.txt file. The best way to do this is using Automatic Robots.txt, which blocks all agents of this type and updates continuously as new agents are released. While the vast majority of agents operated by reputable companies honor these robots.txt directives, bad actors may choose to ignore them entirely. In that case, you'll need to implement alternative blocking methods such as firewall rules or server-level restrictions. You can verify whether Netcraft is respecting your rules by setting up Agent Analytics to monitor its visits to your website.

Will Blocking Netcraft Hurt My SEO?

Blocking intelligence gatherers has minimal direct SEO impact since they don't control search indexing. However, if competitors use these tools to monitor your SEO strategy, blocking them might actually provide competitive advantages by limiting their access to your optimization tactics and performance data.

Does Netcraft Access Private Content?

Intelligence gatherers typically focus on publicly accessible business information, but their scope can vary significantly. Some limit themselves to public websites and social media, while others may attempt to access restricted databases, employee directories, or other sensitive information sources. The scope depends on the operator's objectives and ethical boundaries.

How Can I Tell if Netcraft Is Visiting My Website?

Setting up Agent Analytics will give you realtime visibility into Netcraft visiting your website, along with hundreds of other AI agents, crawlers, and scrapers. This will also let you measure human traffic to your website coming from AI search and chat LLM platforms like ChatGPT, Perplexity, and Gemini.

Why Is Netcraft Visiting My Website?

Netcraft likely identified your site as relevant to their clients' business intelligence needs. Your site may contain information about competitors, market data, pricing, or other business insights that their monitoring system was configured to track and analyze.

How Can I Authenticate Visits From Netcraft?

Agent Analytics authenticates agent visits from many agents, letting you know whether each one was actually from that agent, or spoofed by a bad actor. This helps you identify suspicious traffic patterns and make informed decisions about blocking or allowing specific user agents.

References

• https://netcraft.com/blog/june-2025-web-server-survey