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. Agent Analytics can track when it visits your website.
Category
Expected Behavior
Netcraft SSL Server Survey's pattern depends on who pointed it at you. Continuous monitoring services check daily or even hourly, while a one time assessment sweeps once and disappears. Expect requests aimed at login pages, admin paths, APIs, and configuration files, because exposed ones are what scanners exist to find.
Overview
| Operated By | Netcraft |
| Expected To Follow Robots.txt | Yes |
| Insights Last Updated | July 6, 2026 |
Robots.txt Blocked Percentage
Country of Origin
Robots.txt Blocking Trend
As of July 6, 2026, 0% of top websites block Netcraft SSL Server Survey in their robots.txt files.
Overall Security Scanner Traffic
As of July 6, 2026, 0.0% of all web traffic came from security scanners.
This data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the world's top 1000 websites and their robots.txt files.
Netcraft SSL Server Survey's User Agent
| User Agent | Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; Netcraft SSL Server Survey - contact info@netcraft.com) |
Access other known user agents and IP addresses using the Enterprise API.
How To Block Netcraft SSL Server Survey
Add this rule to your robots.txt file to block Netcraft SSL Server Survey from accessing your entire website. 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: /Frequently Asked Questions
Should I Block Netcraft SSL Server Survey?
Not unless you already run your own scanning and want cleaner logs. Netcraft SSL Server Survey checks websites for exposed vulnerabilities, and some scanning services report what they find to site owners for free. Almost none of the top websites we track have robots.txt rules for Netcraft SSL Server Survey right now.
Does Netcraft SSL Server Survey Respect Robots.txt?
Yes. Netcraft SSL Server Survey is expected to honor robots.txt rules, so a disallow rule is the right first move. Automatic Robots.txt adds and maintains that rule for you, and Agent Analytics confirms Netcraft SSL Server Survey actually honors it.
Does Netcraft SSL Server Survey Access Private Content?
It probes for private content deliberately. Login pages, admin panels, and API endpoints are exactly what Netcraft SSL Server Survey tests, because exposed ones are what it exists to find. Probing is not the same as getting in, but expect requests to sensitive paths in your logs.
Why Is Netcraft SSL Server Survey Visiting My Website?
Netcraft SSL Server Survey is scanning your site for vulnerabilities, either as part of a sweep across the whole internet or because someone requested an assessment of your domain. Recurring visits usually mean a monitoring service has you on its list.
How Can I Tell if Netcraft SSL Server Survey Is Visiting My Website?
Agent Analytics tracks Netcraft SSL Server Survey visits in real time alongside every other known AI agent, crawler, and scraper. You can also check your server logs for requests whose user agent string contains "Netcraft SSL Server Survey". Look for probes of login, admin, and API paths. Keep in mind that Netcraft SSL Server Survey doesn't publish a verification method, so any client can claim its user agent string and a log match is a hint rather than proof.