What is MJ12bot?
MJ12bot is Majestic's web crawler that maps link relationships between websites to build a comprehensive link graph for SEO analysis, providing backlink data and domain authority metrics without caching personal content. Agent Analytics can track when it visits your website.
Overview
| Operated By | Majestic |
| Source | Official Website |
| Expected To Follow Robots.txt | Yes |
| Insights Last Updated | July 31, 2026 |
Do you operate this agent? Contact us to suggest an update.
Category
Expected Behavior
MJ12bot maps sites the way its customers' SEO tools need, following internal links to build a full picture of structure, content, and ranking signals. Expect thorough crawls rather than spot checks, with frequency rising when your site or your competitors are actively monitored in its tools.
MJ12bot's User Agent
| User Agent | Mozilla/5.0 (compatible; MJ12bot/v2.0.5; http://mj12bot.com/) |
How To Block MJ12bot With Robots.txt
Add this rule to your robots.txt file to block MJ12bot from accessing your entire website, or use Automatic Robots.txt to block all SEO crawlers at once. You can customize which pages are blocked by swapping out / for a different path.
User-agent: MJ12bot # https://knownagents.com/agents/mj12bot
Disallow: /Global Insights for MJ12bot
As of July 31, 2026, this data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the world's top 1000 websites and their robots.txt files.
Robots.txt Blocked Percentage
Country of Origin
Robots.txt Blocking Trend
5% of top websites block MJ12bot in their robots.txt files.
Overall SEO Crawler Traffic
3.1% of all web traffic came from SEO crawlers.
Top Visited Website Categories
The types of websites most frequently visited by MJ12bot.
Frequently Asked Questions
Should I Block MJ12bot?
Only if you want your own pages and outbound links out of those tools. MJ12bot collects the ranking and backlink data behind SEO tools, likely including ones you or your agency use, and it does not change how search engines rank you. Blocking it will not hide your backlink profile either, because backlinks are discovered on the sites that link to you. For comparison, 5% of the top websites we track already have robots.txt rules for MJ12bot.
Does MJ12bot Follow Robots.txt Rules?
Yes. MJ12bot is expected to follow robots.txt rules, so a disallow rule is the right first move. Automatic Robots.txt adds and maintains that rule for you, and Agent Analytics confirms MJ12bot actually follows it.
Does MJ12bot Access Private Content?
Login walls stop it. MJ12bot analyzes public pages for rankings, links, and site structure.
Why Is MJ12bot Visiting My Website?
Your domain shows up in the ranking, backlink, and competitor data MJ12bot's operator sells. If anyone tracks your site or your competitors in an SEO tool, MJ12bot visits you.
How Can I Tell if MJ12bot Is Visiting My Website?
Agent Analytics tracks MJ12bot visits in real time alongside every other known AI agent, crawler, and scraper. You can also check your server logs for requests whose user agent string contains "MJ12bot". Look for full site crawls that follow your internal links. Keep in mind that MJ12bot doesn't publish a verification method, so any client can claim its user agent string and a log match is a hint rather than proof.