About
Majestic's web crawler that builds one of the web's largest link intelligence databases, used by SEO professionals worldwide. Majestic's data is increasingly consumed by AI-powered SEO tools and marketing agents. As large language models are integrated into SEO workflows, content indexed by MJ12bot can be surfaced, summarised, or compared by AI systems without direct page visits. Known to be among the most aggressive crawlers by volume.
Purpose
Link intelligence database and AI SEO tool support
User Agent String
MJ12bot/v1.4.8 (http://majestic.com/research/majestic-12?V=1.4.8)
How to Control in robots.txt
🚫 Block MJ12bot
User-agent: MJ12bot Disallow: /
✅ Allow MJ12bot
User-agent: MJ12bot Allow: /
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