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Agent directory · Other bot

facebookexternalhit

Fetches a page to build the preview when someone shares a link on Facebook, Instagram, Messenger or WhatsApp.

Run by
Meta
Type
Other bot
Robots.txt name
facebookexternalhit
Verifiable
No

What facebookexternalhit does

Fetches a page to build the preview when someone shares a link on Facebook, Instagram, Messenger or WhatsApp.

It's a well-known bot that isn't an AI agent. The kinds of AI agent that visit websites.

Should you allow it?

Usually allow it: these bots support products you already use. A decision guide for blocking or allowing AI crawlers.

How to allow or block facebookexternalhit

facebookexternalhit reads the facebookexternalhit group in your robots.txt. To block it everywhere:

User-agent: facebookexternalhit
Disallow: /

To allow it everywhere, even if another rule blocks other bots:

User-agent: facebookexternalhit
Allow: /

Robots.txt is a request, not a lock: well-behaved crawlers follow it, impostors don't. Robots.txt for AI agents.

How it identifies itself

A typical user agent:

facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)

How to tell if it's really facebookexternalhit

Meta doesn't publish IP ranges or a reverse DNS domain for facebookexternalhit, so a request can't be proven to come from it. Anyone can send its user agent, so treat the name alone as a claim, not proof. Ghost Agent Lab reports these requests as unverified rather than guessing.

Every Meta agent, and a robots.txt for all of them →

Does facebookexternalhit visit your site? Ghost Agent Lab reads your CDN or server logs and shows every request from facebookexternalhit and 1,566+ other known agents: what they read, what your site sent back, and whether each request was genuine. See agent traffic, or check whether AI agents can use your site for free.