MJ12bot (Majestic): what it is and how to allow or block it

MJ12bot is Majestic's crawler that maps link relationships between websites for its search engine and backlink index. Its robots.txt token is MJ12bot.

Facts

Operator: Majestic

Category: SEO tool crawler

robots.txt token: MJ12bot

Honors robots.txt?: Yes, per Majestic. Majestic lists it as a crawler that obeys robots.txt and identifies itself. Crawl-Delay is supported up to 20 seconds; higher values are rounded down.

User-agent example: Contains mj12bot (the operator documents no full example string)

Official source: Majestic: MJ12bot

Compared with the source: 2026-10-18

What it is used for

Maps the link relationships between websites. The data is a web graph of links that feeds Majestic's Site Explorer backlink index. Crawls the web for a marketing or SEO tool, mostly to build a backlink or site database. It does not decide whether you rank, and blocking it only removes you from that tool's data.

What happens if you block it

Add a User-agent: MJ12bot group with Disallow: /. A bot-specific section takes precedence over the * section.

How to allow or block MJ12bot

Add one of these groups to the robots.txt at the root of your domain. A group that names the bot overrides a general User-agent: * group.

Allow MJ12bot

User-agent: MJ12bot
Allow: /

Block MJ12bot

User-agent: MJ12bot
Disallow: /

Does your site allow MJ12bot today? The checker evaluates your robots.txt for this and every other bot.Check my site

What we see on our own sites

No request identifying as MJ12bot has been recorded in the last 30 days, so there is nothing to show yet. We never fill this in with estimates.

Counts come from the websites we operate; they hold no IP addresses or URLs, and a user agent is only a claim. See the bot traffic data and the methodology.

Other SEO tool crawlers

All SEO Tool Crawlers · Bot directory · Which bots to allow or block · robots.txt generator · See a page as a bot