Semrush
SemrushBot
Collects web and link data for Semrush analysis tools.
SEO analysisSEO analysis
MJ12bot
Builds web link data for Majestic using a distributed crawler.
Operated by Majestic
See your agent traffic PurposeSEO analysis
HTTP identifierMJ12bot
IdentityVerify beyond the name
THE SIGNAL
What this visit tells you
Link graph maintenance can revisit URLs long after your site changes. Frequency alone does not show commercial interest.
Linked URL failures
Crawl frequency
Origin load
Your next move
Inspect linked missing pages before deciding on redirects. Choose crawl limits based on origin load and your link-data policy.
The technical details
MarkdownHow to identify it
Look for the MJ12bot identifier in a request’s User-Agent. This is a name match, not identity verification. Version strings may change.
How to check identity
For stronger attribution, arrange a private CRAWLER-IDENT header with Majestic and compare it on requests to your domain.
Access and robots.txt
MJ12bot supports robots.txt and Crawl-delay up to 20 seconds. Its distributed crawlers can make overlapping requests, so inspect aggregate load.
Optional full-site opt-out. Merge with existing rules only if intended. robots.txt does not secure private content.
User-agent: MJ12bot
Disallow: /Seeing 403 or 404 responses?
403 means access was denied; 404 means the resource was not found. Compare the public path, request time, edge security event and origin response to find the cause.
Separate intended restrictions and secret-file probes from pages that should work. A User-Agent name alone does not justify allowing a request.
SourcesReviewed 2026-09-14
Identity and purpose are based on these sources. Analytics interpretation and suggested checks are Apostl guidance.
APOSTL PulseSee MJ12bot in context
See their requests. Find the pages that matter.
See your agent traffic