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MJ12bot

MJ12bot is a web crawler operated by Majestic-12 Ltd, a UK-based company that builds a search engine focused on backlink analysis and web structure mapping.
UnverifiableMajestic-12 LtdMJ12bot
SEOSearch Engine Crawler

What is MJ12bot?

MJ12bot is Majestic-12 Ltd's search engine crawler. MJ12bot is a web crawler operated by Majestic-12 Ltd, a UK-based company that builds a search engine focused on backlink analysis and web structure mapping. The crawler is part of a distributed community-based system that helps build Majestic's link intelligence database.

MJ12bot powers a search engine, and search indexes increasingly feed AI answers and overviews alongside classic results. The pages it can crawl are the pages eligible to rank and to be pulled into AI-generated summaries, so allowing it protects both your SEO and your AI search visibility.

Like any automated client, MJ12bot consumes crawl budget and appears in your server and CDN logs. Reviewing those logs alongside your robots.txt rules helps you keep automated traffic deliberate and easy to reason about.

Want to see every AI bot hitting your site? Promptwatch turns your server and CDN logs into a live view of AI crawler and agent traffic, so you can watch ChatGPT, Claude, Perplexity, Gemini, and others crawl your pages and connect those visits to real citations and revenue. Learn more in AI crawler logs.

See every AI bot hitting your site

Promptwatch turns your server and CDN logs into a live view of AI crawler and agent traffic. Watch ChatGPT, Claude, Perplexity, Gemini, and more crawl your pages in real time, see exactly what they take, and connect every crawl to the citations and revenue it drives.

How to handle MJ12bot

Most sites keep MJ12bot allowed, because blocking it can remove your pages from the AI answers and search results it powers. Only disallow it if you specifically want to opt out of that surface.

To control MJ12bot, add a rule for its user agent to your robots.txt:

User-agent: MJ12bot
Disallow: /

MJ12bot generally honors robots.txt directives.

Examples

  • After publishing a new comparison page, a marketer checks whether MJ12bot has fetched it so the content can appear in AI answers.
  • An SEO lead keeps MJ12bot allowed in robots.txt to preserve visibility in AI-powered search.

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Frequently asked questions about MJ12bot

Learn about AI visibility monitoring and how Promptwatch helps your brand succeed in AI search.

MJ12bot is operated by Majestic-12 Ltd. It functions as Majestic-12 Ltd's search engine crawler.

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