Netcraft SSL Server Survey

scanner Netcraft SSL Server Survey

Netcraft SSL certificate intelligence scanner

About this crawler

Netcraft SSL Server Survey is a web crawler identified by the regular-expression pattern Netcraft SSL Server Survey in the User-Agent request header. It is categorised as scanner. Use the regex above to detect, log, allow, or block Netcraft SSL Server Survey traffic in your web server, CDN edge rules, or robots.txt.

Block-rate · top 25k sites

0.33%
latest snapshot
2026-06-04
matched key: Netcraft
2026-05-012026-06-040.52%

Technical details

Name
Netcraft SSL Server Survey
Pattern
Netcraft SSL Server Survey
Tags
scanner
Reference
https://knownagents.com/agents/netcraft-ssl-server-survey
Added
2026/04/26
Instances
1 known sample(s)

Sample User-Agent strings

Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; Netcraft SSL Server Survey - contact [email protected])

Block this crawler

robots.txt — disallow Netcraft SSL Server Survey:

User-agent: Netcraft SSL Server Survey Disallow: /

Apache .htaccess — return 403:

RewriteEngine On RewriteCond %{HTTP_USER_AGENT} Netcraft SSL Server Survey [NC] RewriteRule .* - [F,L]

Nginx — return 403 inside a server block:

if ($http_user_agent ~* "Netcraft SSL Server Survey") { return 403; }
← back to all crawlers