AI crawler index

What is meta-externalagent?

meta-externalagent is Meta's crawler for AI training. Crawls for uses such as training AI models or improving products by indexing content directly.

At a glance

Operator	Meta
Purpose	AI training
User agent	`meta-externalagent/1.1`
Obeys robots.txt	Yes, according to the operator
Published IP ranges	Not documented by the operator
How to verify it	Not documented by the operator
Official documentation	https://developers.facebook.com/documentation/sharing/webmasters/web-crawlers

Should you block meta-externalagent?

It collects pages for model training, not for answering questions in real time. Blocking it keeps your future content out of that operator's training data, but it does not take you out of AI search answers, which other crawlers feed. Block it if you do not want your content in training sets; allow it if you want future models to know your brand.

Meta AI's search citations use a separate crawler, meta-webindexer. Meta may cache robots.txt for up to 24 hours.

How to block or allow meta-externalagent in robots.txt

Block it everywhere:

User-agent: meta-externalagent
Disallow: /

Allow it everywhere:

User-agent: meta-externalagent
Allow: /

Rules are matched by the token on the User-agent line. Test the result with the robots.txt tester before you publish it.

How to verify that a visit is really meta-externalagent

Meta publishes no IP list or hostname for meta-externalagent, so you cannot prove a visit is genuine. Treat the user agent as a claim and judge the visits by what they request in your logs.

Other Meta crawlers

meta-externalfetcher: User-triggered fetch
meta-webindexer: AI search
facebookexternalhit: Link preview

Check your own site

The AI crawler checker tells you which AI crawlers your robots.txt lets in, and the log file analyzer shows how often each one actually visits. For the bigger picture, see what AI crawlers are and the full AI crawler index.

What our data says about meta-externalagent

Figures we measured on real AI answers and websites. Each one links to its study, with the method, the sample and the date.

12%

12% of the websites AI cites most in Spain block meta-externalagent from crawling their site, and 11.5% name it in a robots.txt group of its own.

Sample: 382 websites AI cites for three or more of 43 brands in Spain. Source: Mencoro (October 2026), in Which AI crawlers do the websites AI cites let in?