Skip to content

Link preview bot

What is facebookexternalhit?

facebookexternalhit is the bot Meta uses to build link previews when someone shares your page on Facebook, Instagram or WhatsApp.

Link previewPartly followsNo way to verify
Operator
Meta
Purpose
Link preview. Builds the preview card when someone shares your link in a chat or social app.
robots.txt token
facebookexternalhit
Sample user agent
facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)User agents change with versions. Match on the token, not the full string.
Follows robots.txt
Partly. Meta says it might bypass robots.txt when performing security or integrity checks.
How to verify
Meta doesn't publish a way to verify it.
Sources
Meta documentation
Last reviewed

Allow or block facebookexternalhit

Block facebookexternalhit
User-agent: facebookexternalhit
Disallow: /

Asks facebookexternalhit not to crawl any page. Well-behaved crawlers stop; it does not stop anyone who ignores robots.txt.

Allow facebookexternalhit
User-agent: facebookexternalhit
Allow: /

Lets facebookexternalhit crawl everything. You only need this if a broader rule would otherwise block it.

Should you block it?

Blocking facebookexternalhit breaks the preview card when someone shares your link on Meta.

Write a full policy with the AI Crawler Policy Generator

facebookexternalhit can't be verified

Meta doesn't publish IP ranges, DNS names or signatures for facebookexternalhit. The user agent is the only signal, and anyone can copy it, so treat a request that claims to be facebookexternalhit as unproven.

Questions about facebookexternalhit

Is facebookexternalhit safe to allow?

facebookexternalhit reads public pages; it does not log in or submit forms. Whether to allow it depends on whether you want Meta's product to use your pages.

How do I know a request is really facebookexternalhit?

You can't, from the request alone. Meta doesn't publish IP ranges, DNS names or signatures for it, so the user agent is the only signal, and anyone can copy that.

How often does facebookexternalhit visit?

It depends on your site; Meta doesn't publish a schedule. Referscope shows the real visits.

Related crawlers

All AI crawlers

Free tools for facebookexternalhit

AI Crawler Policy Generator

Build a robots.txt that blocks AI training and keeps AI search and Google.

Build your robots.txt

AI Bot Verification Tester

Paste an IP and user agent from your logs and see if the bot is real.

Verify a bot

robots.txt Checker

See which AI crawlers your robots.txt allows or blocks.

Check robots.txt

Less guessing. Clearer growth.

Connect your site today and see your first verified AI crawler by tomorrow.

Explore ReferscopeBecome a design partner