GC

grub-client

search-engine grub-client

Grub search engine web crawler for indexing

About this crawler

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

Block-rate · top 25k sites

0.65%
latest snapshot
2026-06-04
matched key: grub-client
2026-05-012026-06-040.96%

Technical details

Name
grub-client
Pattern
grub-client
Tags
search-engine
rDNS suffixes
.grub.org
Instances
11 known sample(s)

rDNS verification (FCrDNS)

Verify a request is genuinely grub-client with forward-confirmed reverse DNS: the client IP's PTR record must end in one of the suffixes below and a forward A/AAAA lookup of that hostname must return the same IP. UA strings alone are spoofable; FCrDNS is not.

Sample User-Agent strings

Mozilla/4.0 (compatible; grub-client-0.3.0; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.0.4; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.0.5; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.0.6; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.0.7; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.1.1; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.2.1; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.3.1; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.3.7; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.4.3; Crawl your own stuff with http://grub.org)
Mozilla/4.0 (compatible; grub-client-1.5.3; Crawl your own stuff with http://grub.org)

Block this crawler

robots.txt — disallow grub-client:

User-agent: grub-client Disallow: /

Apache .htaccess — return 403:

RewriteEngine On RewriteCond %{HTTP_USER_AGENT} grub-client [NC] RewriteRule .* - [F,L]

Nginx — return 403 inside a server block:

if ($http_user_agent ~* "grub-client") { return 403; }
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