SEO tools · Majestic

MJ12bot

Majestic’s distributed crawler for its link index. Blocking it does not affect search engines.

Operator: Majestic
Purpose: Backlink & SEO index. Crawlers behind backlink and SEO tools. Many sites block them to save bandwidth; it has no effect on search.
robots.txt token: MJ12bot
User agent: Mozilla/5.0 (compatible; MJ12bot/v1.4.8; http://mj12bot.com/)
Documentation: mj12bot.com/

Block MJ12bot

Add a group naming it to /robots.txt. Compliant crawlers stop before requesting any page. A firewall rule on the user agent is the only way to enforce it against crawlers that ignore robots.txt.

User-agent: MJ12bot
Disallow: /

Allow MJ12bot when everything else is blocked

A group naming the bot wins over User-agent: *, so an explicit allow lets it in while your catch-all rules stay in place.

User-agent: MJ12bot
Allow: /

User-agent: *
Disallow: /

Does MJ12bot reach your site?

The checker applies your robots.txt the way MJ12bot does, then requests your page with the user agent above, alongside 29 other bots.

Other seo tools: AhrefsBot, SemrushBot, DotBot.

Build a complete file with the robots.txt generator.