What is MJ12Bot?
Direct Answer: MJ12bot is a web crawler operated by Majestic for SEO backlink analysis and search engine data mapping.
MJ12bot is the web crawler for Majestic, mapping link relationships between websites to build a search engine. It does not cache web content or personal data. The data collected is available for searching keywords or websites at Majestic.
User-Agent Identification
The following user-agent strings identify MJ12Bot in your live traffic data:
Mozilla/5.0 (compatible; MJ12bot/v1.4.8; http://mj12bot.com/)
robots.txt Rules for MJ12Bot
Respects robots.txt: No
This bot does not commit to following robots.txt
MJ12Bot does not officially follow robots.txt directives. The only reliable way to control access is through server-side blocking (IP filtering, user-agent rules in your web server config) combined with log monitoring to verify effectiveness.
Need continuous verification across 500+ bots? Can AI See It automates this.
Crawl Behavior
Frequency:Not Documented
Request Pattern:Not Documented
Crawl Activity Index
Relative crawl activity for MJ12Bot over the past 28 days. Higher values indicate increased crawling intensity compared to the period baseline.
View recent activity data (last 7 days)
| Date | Activity Index |
|---|---|
| Mar 28, 2026 | 63.3 |
| Mar 29, 2026 | 63.7 |
| Mar 30, 2026 | 60.3 |
| Mar 31, 2026 | 57.5 |
| Apr 1, 2026 | 64.7 |
| Apr 2, 2026 | 64.9 |
| Apr 3, 2026 | 68.5 |
Source: Cloudflare Radar
Why track MJ12Bot traffic?
Control third-party crawl impact on your server. MJ12Bot crawls your site to build Majestic's SEO database. While useful for competitive analysis, these crawlers can consume significant server resources on large sites.
Identify who's analyzing your site. MJ12Bot visits reveal when competitors or agencies are running audits on your domain.
Manage crawl priority. If MJ12Bot is consuming crawl budget you'd rather allocate to search engines, you can throttle or block it based on measured volume.
Surface 4XX and 5XX errors before search engines find them. If MJ12Bot reports broken pages or server errors in its crawl data, you can fix those issues proactively — before search engine crawlers encounter them and your rankings suffer.
Is MJ12Bot worth the server resources?
MJ12Bot crawls your site to build Majestic's SEO database. Unlike search engines, this crawler doesn't send you any referral traffic — it feeds a third-party tool.
That's not necessarily a problem — Majestic's data may power tools you use yourself. The question is whether MJ12Bot's crawl volume is proportionate to its value.
What Can AI See It measures
Requests per day and bandwidth consumed by MJ12Bot
What % of your total bot traffic is MJ12Bot?
Scrapers spoofing MJ12Bot's user-agent string
Log Verification
To verify MJ12Bot traffic in your live traffic data:
- Search access logs for the user-agent strings listed above
- Check if the IP addresses match documented ranges (if provided by Majestic)
- Verify the crawl pattern matches documented behavior
- Use reverse DNS lookup for additional verification if available
Note: Observed behavior in production environments may differ from official documentation. Live traffic monitoring provides the only reliable verification of actual bot behavior.
Undocumented Information
The following information is not officially documented for MJ12Bot:
- crawl frequency
- IP verification
- JavaScript rendering
- request pattern
See which SEO tools are crawling your site — and how much they cost you
- Identify third-party crawlers consuming your server resources
- Separate SEO tool traffic from search engine crawls
- Detect fake bots spoofing MJ12Bot's user-agent
Official Documentation
View Official MJ12Bot Documentation →
Information sourced from official documentation. Content generated with AI assistance.