Meta-ExternalAgent
Meta · Model training · robots.txt token meta-externalagent
5% of 30,177 measured domains disallow meta-externalagent in robots.txt at the site root. Separately, and independently of robots.txt, 17.4% of 30,185 reachable domains refuse an AI crawler user agent at the network edge on two consecutive probes from different locations - a refusal the site's own robots.txt does not declare and its owner often has not chosen.
Measured 2026-10-06 by direct request to every domain in the corpus. Method: how this is measured. Reuse under CC BY 4.0 with attribution.
Cite as: Crawl Census, "Meta-ExternalAgent blocking rate", measured 2026-10-06. https://crawlcensus.com/bot/meta-externalagent
What it is definition
Crawls the web to train Meta's foundation AI models and to index content directly into products.
Meta-ExternalAgent is operated by Meta and classified here as model training. These agents collect text and images that may end up in a training corpus. Disallowing one withholds new content from the next model. It does not withdraw anything collected before the disallow, and it does not remove the site from any answer engine.
Disallowing meta-externalagent withholds content crawled from that point on from Meta's training data. It does not withdraw pages collected in earlier crawls, it does not reach copies already sitting in third-party datasets, and it does not remove the site from any answer surface.
- robots.txt token
- meta-externalagent
- Operator
- Meta
- Purpose
- Model training
- Honors robots.txt
- yes
- Documentation
- https://developers.facebook.com/docs/sharing/webmasters/web-crawlers/
Identity on the wire exact string
meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/web-crawlers)curl -A 'meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/web-crawlers)' https://example.com/Replace the host with your own. A 403, a challenge page or an empty body means the edge is blocking the agent whatever robots.txt says.
How to allow it, how to block it robots.txt
User-agent: meta-externalagent
Allow: /Absent any rule, the agent is already allowed, so this group only matters when your * group disallows something. Naming the agent replaces the * group for it entirely, so repeat here every disallow you still want to apply to it.
User-agent: meta-externalagent
Disallow: /Disallowing meta-externalagent withholds content crawled from that point on from Meta's training data. It does not withdraw pages collected in earlier crawls, it does not reach copies already sitting in third-party datasets, and it does not remove the site from any answer surface.
Sites that block it 60 shown
See every measured domain that blocks Meta-ExternalAgent
This list is served from a cache rebuilt just now. It is discarded the moment a rescan records a policy change for this agent, so a site that has just changed its robots.txt will drop off it within one scan rather than waiting for the cache to expire.
Compare Meta
Meta runs 6 agents in this registry, and they do different jobs. Blocking one says nothing about the others.
Common questions answered
Does blocking Meta-ExternalAgent remove me from Meta AI?
No, not by itself. Meta-ExternalAgent collects content for training, not for the index that answers questions. Meta's answer surfaces are governed separately by meta-externalfetcher, meta-webindexer and facebookexternalhit, which stay allowed unless you disallow them too. Content collected before the disallow is not withdrawn.
How do I verify Meta-ExternalAgent requests are genuine?
Meta's crawlers originate from AS32934, and Meta documents querying that ASN to obtain the current ranges. Map the source address to its ASN and check for AS32934. There is no published reverse DNS name.
Check your own site free
See whether your robots.txt admits Meta-ExternalAgent today, and whether your edge agrees with it.