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MJ12bot
Majestic-12 search engine web crawler bot
About this crawler
MJ12bot is a web crawler identified by the regular-expression pattern MJ12bot in the User-Agent request header. It is categorised as seo. Use the regex above to detect, log, allow, or block MJ12bot traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
5.2%
Technical details
- Name
- MJ12bot
- Pattern
MJ12bot- Tags
- seo
- rDNS suffixes
.majestic.com,.majestic12.co.uk- Instances
- 21 known sample(s)
rDNS verification (FCrDNS)
Verify a request is genuinely MJ12bot 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.
.majestic.com.majestic12.co.uk
Sample User-Agent strings
MJ12bot/v1.0.8 (http://majestic12.co.uk/bot.php?+)
MJ12bot/v1.2.0 (http://majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.2.1; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.2.3; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.2.4; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.2.5; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.3.0; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.3.1; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.3.2; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.3.3; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.4.0; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.4.1; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.4.2; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.4.3; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.4.4 (domain ownership verifier); http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.4.4; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.4.5; http://www.majestic12.co.uk/bot.php?+)
Mozilla/5.0 (compatible; MJ12bot/v1.4.6; http://mj12bot.com/)
Mozilla/5.0 (compatible; MJ12bot/v1.4.7; http://mj12bot.com/)
Mozilla/5.0 (compatible; MJ12bot/v1.4.7; http://www.majestic12.co.uk/bot.php?+)
+ 1 more samples in crawlers.json
Block this crawler
robots.txt — disallow MJ12bot:
User-agent: MJ12bot
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} MJ12bot [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "MJ12bot") {
return 403;
}
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