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. You can set up Agent Analytics to see when MJ12bot visits your website.
Overview
| Operated By | Majestic |
| Source | Official Website |
| Expected To Follow Robots.txt | Yes |
| Insights Last Updated | September 14, 2026 |
Do you operate this agent? Contact us to suggest an update.
Category
Expected Behavior
MJ12bot usually performs comprehensive, link-following crawls rather than spot checks. Visit frequency may rise while a customer actively monitors your site or a related market.
MJ12bot's User Agent
| User Agent | Mozilla/5.0 (compatible; MJ12bot/v1.4.8; http://mj12bot.com/) |
How To Block MJ12bot With Robots.txt
Add this rule to your robots.txt file to block MJ12bot from accessing your 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: /Insights for MJ12bot
As of September 14, 2026, this data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the top 1000 websites and their robots.txt files.
Robots.txt Blocked Percentage
Country of Origin
Robots.txt Blocking Trend
10% of top websites block MJ12bot in their robots.txts.
Overall SEO Crawler Traffic
1.7% 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?
Consider blocking MJ12bot only if you do not want your pages included in SEO databases. It does not influence how search engines rank you, and blocking it will not hide backlinks to your site because those are discovered on the linking sites. For context, 10% of the top websites we track currently 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 appropriate first step. Automatic Robots.txt can add and maintain that rule, while Agent Analytics lets you verify whether MJ12bot respects it.
Does MJ12bot Access Private Content?
No. MJ12bot can reach only public pages, and authentication prevents it from accessing private content.
How Can I Tell if MJ12bot Is Visiting My Website?
Agent Analytics tracks MJ12bot visits in real time. You can also check your server logs for requests whose user-agent string contains "MJ12bot". Look for comprehensive site crawls that follow internal links. Because MJ12bot does not publish a verification method, any client can claim its identity and a log match is only a clue.
Why Is MJ12bot Visiting My Website?
Your domain appears in the ranking, backlink, or competitor data maintained by MJ12bot's operator. A customer may be tracking your site, one of your competitors, or a backlink that connects another site to yours.