FacebookBot
An older Meta crawler documented as collecting public data to train AI models, including speech recognition systems.
FacebookBotOfficial documentation: developers.facebook.com
What FacebookBot does
FacebookBot predates Meta-ExternalAgent and is documented by Meta as crawling public pages to help train AI. It honors robots.txt per Meta's documentation. Much of its historical role has been superseded by the newer token.
Why it visits your site
Training data collection for Meta's AI efforts.
The bigger picture: AI training crawlers
Training crawlers are the most economically lopsided visitors your server has. A search crawler takes your content and pays you back in ranked listings and click-throughs; a training crawler takes the same content to improve a commercial model and, by design, sends nothing in return. The visit itself is the entire transaction. That asymmetry is why training bots - not AI in general - are where most of the blocking debate actually lives, and why the publishing industry's response has split between refusal and negotiation: several large publishers block these crawlers outright, while others have signed licensing deals with the same operators. Both strategies start from the same place - knowing, concretely, how much of your archive is being read and by whom.
The norms here are young and still hardening. The better operators now publish user agents, IP ranges, and opt-out tokens, and honor robots.txt; others publish nothing and, by widely credited reports, crawl through disallow rules. Treat each crawler on its record rather than assuming the category behaves uniformly - and remember that a robots.txt line only ever governs the polite end of the spectrum.
Should you block it?
If you are blocking Meta's AI training, block both FacebookBot and meta-externalagent; neither affects link previews, which use facebookexternalhit.
Block via robots.txt
Add these lines to the robots.txt at your site root to ask FacebookBot to stay away:
User-agent: FacebookBot Disallow: /
Remember that robots.txt is a request, not a lock - compliance is voluntary, and enforcement happens at the server. Viz's AI Control pairs robots.txt rules with server-level 403 responses and then probes your site to verify the block is actually holding.
How to see FacebookBot traffic on your site
You have three windows onto it, each with a catch. Raw hosting access logs contain every FacebookBot request, but many managed WordPress hosts don't expose them, and when they do you are grepping text files by hand. A CDN dashboard sees the traffic at the edge, but it lives outside WordPress and speaks in totals, not in your site's terms. And JavaScript analytics - GA4 and friends - will never show it at all, because FacebookBot doesn't run scripts.
Viz's answer is the request log: filter to FacebookBot and read exactly which URLs it fetched and when, right inside wp-admin - then watch the same filter after any blocking decision to see whether the visits stopped, slowed, or kept coming.