facebookexternalhit

Operator

Meta/Facebook

robots.txt token

facebookexternalhit

Follows robots.txt

No, according to ai.robots.txt.

In Vireo

Excluded, reported under Link previews

What it does

Note that excluding FacebookExternalHit will block incorporating OpenGraph data when sharing in social media, including rich links in Apple's Messages app. [According to Meta](https://developers.facebook.com/docs/sharing/webmasters/web-crawlers/), its purpose is "to crawl the content of an app or website that was shared on one of Meta’s family of apps...". However, see discussions [here](https://github.com/ai-robots-txt/ai.robots.txt/pull/21) and [here](https://github.com/ai-robots-txt/ai.robots.txt/issues/40#issuecomment-2524591313) for evidence to the contrary.

ai.robots.txt describes its function as: Ostensibly only for sharing, but likely used as an AI crawler as well

Source: ai.robots.txt.

How to block or allow facebookexternalhit

Add a group for its token to the robots.txt file at the root of your site. To keep it out of the whole site:

User-agent: facebookexternalhit
Disallow: /

To let it crawl everything, use an empty Disallow: or Allow: / instead. WordPress serves a virtual robots.txt that many SEO plugins let you edit. A real robots.txt file uploaded to the site root takes its place.

robots.txt is a request, so it only works on crawlers that honour it. A bot that ignores it has to be blocked at the server or firewall, by user agent or IP address.

How Vireo counts facebookexternalhit

When a request's user agent contains facebookexternalhit, Vireo keeps it out of your pageviews and visitors and counts them on its bot report under Link previews, so you can see how much it left out rather than wonder why your server logs show more traffic.

Checked by running Vireo Analytics' own bot filter over the bot's name.

Sources

• ai.robots.txt (MIT)