What is Netcraft SSL Server Survey?

Netcraft SSL Server Survey is a security scanner operated by Netcraft, a cybersecurity and digital risk protection company. This bot scans websites to collect SSL/TLS certificate information as part of their threat intelligence operations and web infrastructure security analysis. You can set up Agent Analytics to see when Netcraft SSL Server Survey visits your website.

Category

Security Scanner
Scans websites for security vulnerabilities, threats, and configuration weaknesses

Overview

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Example User Agent Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; Netcraft SSL Server Survey - contact info@netcraft.com)
Operated By Netcraft
Triggered By Scheduled or requested scan
Used for AI Model Training Not expected
Affects AI Chat & Search Visibility Not directly
Expected To Follow Robots.txt Yes

Why Is Netcraft SSL Server Survey Visiting My Website?

Netcraft SSL Server Survey is scanning your site for vulnerabilities, either as part of an internet-wide sweep or because someone requested an assessment of your domain. Recurring visits often indicate that a monitoring service has added your site to its checks.

Should I Block Netcraft SSL Server Survey?

Usually not, unless you already run your own security scans and want cleaner logs. Netcraft SSL Server Survey checks for exposed vulnerabilities, and some services report their findings to site owners at no cost. For context, 7% of the top websites we track currently have robots.txt rules for Netcraft SSL Server Survey.

How Do I Block Netcraft SSL Server Survey Using Robots.txt?

Add this rule to your robots.txt file to block Netcraft SSL Server Survey from accessing your website, or use Automatic Robots.txt to block all security scanners at once. You can customize which pages are blocked by swapping out / for a different path.

User-agent: Netcraft SSL Server Survey # https://knownagents.com/agents/netcraft-ssl-server-survey
Disallow: /

Insights for Netcraft SSL Server Survey

As of October 30, 2026, this data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the top 1000 websites and their robots.txt files.

Robots.txt Compliance

Not enough activity

Country of Origin

United States
Netcraft SSL Server Survey traffic often comes from the United States

Robots.txt Blocked Percentage

7%
7% of top websites are blocking Netcraft SSL Server Survey
Learn How →

Top Visited Website Categories

Not enough activity

Robots.txt Blocking Trend

7% of top websites block Netcraft SSL Server Survey in their robots.txts.

Explore the Data →

Frequently Asked Questions

What Traffic Patterns Should I Expect From Netcraft SSL Server Survey?

Netcraft SSL Server Survey's cadence depends on how the scan is configured. Continuous monitoring may run daily or hourly, while a one-time or internet-wide scan may sweep once and disappear.

Does Netcraft SSL Server Survey Follow Robots.txt Rules?

Netcraft SSL Server Survey is expected to follow robots.txt rules, so a disallow rule is the appropriate first step if you want to block it. Automatic Robots.txt can add and maintain that rule, while Agent Analytics lets you verify whether Netcraft SSL Server Survey respects it.

Is Netcraft SSL Server Survey Used for AI Model Training?

Not ordinarily. Netcraft SSL Server Survey is not categorized as an AI training scraper or data provider, so AI model training is not its expected purpose.

Does Blocking Netcraft SSL Server Survey Affect AI Search or Citations?

Not directly. Netcraft SSL Server Survey's expected purpose is not to supply an AI search index or retrieve pages for AI-generated answers.

Does Netcraft SSL Server Survey Access Private Content?

It deliberately looks for exposed private content. Netcraft SSL Server Survey tests login pages, admin panels, and API endpoints for vulnerabilities. Probing does not mean it gained access, but you should expect requests to sensitive paths in your logs.

How Can I Verify a Request From Netcraft SSL Server Survey?

Agent Analytics tracks Netcraft SSL Server Survey visits in real time. You can also check your server logs for requests whose user-agent string contains "Netcraft SSL Server Survey". Look for bursts of requests to uncommon paths that ordinary visitors rarely access. Because Netcraft SSL Server Survey does not publish a verification method, any client can claim its identity and a log match is only a clue.

How Is Netcraft SSL Server Survey Different From Other Netcraft Agents?

Netcraft operates separate agents for different purposes, so each agent should be evaluated and controlled independently.

  • Netcraft: Netcraft is a web crawler that conducts comprehensive internet surveys, analyzing web server technologies and infrastructure across millions of websites to provide market…
  • NetcraftSurveyAgent: NetcraftSurveyAgent is operated by Netcraft, a cybersecurity company specializing in threat intelligence and digital risk protection. The bot crawls websites to build thr…