What is facebookexternalhit?
facebookexternalhit is Meta's link preview crawler. It fetches a page when someone shares its link in a Meta app, to build the preview.
Last verified 2026-09-30 against the operator's documentation. All bots
facebookexternalhit at a glance
- Operator
- Meta
- Type
- Link preview bots
- Purpose
- Builds link previews when content is shared on Meta's apps.
- robots.txt token
facebookexternalhit- Example user agent
facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)- How to verify
- Meta says a crawler request comes from Meta if its source IP is on the list this command returns: whois -h whois.radb.net -- '-i origin AS32934' | grep ^route. That list covers Meta's whole network (AS32934), not this crawler alone, and Meta notes the addresses change often.
- Operator documentation
- https://developers.facebook.com/docs/sharing/webmasters/web-crawlers/
How often is facebookexternalhit impersonated?
Other apps also put "facebookexternalhit" in their user agent, so a request carrying the name is not always a claim to be Meta's bot. We show no share.
This directory measures requests between 3 July 2026 and 28 September 2026. The fake crawler report covers its own, earlier window (late June to 21 September 2026), so its figures differ from the ones here. Read it for the method.
Have a request that claims to be facebookexternalhit? Check its IP address.
Should you block facebookexternalhit?
- Allow it if
- people share your pages in Meta's apps.
- Block it if
- you never want previews on Meta's apps. Other link preview clients also use this name.
- What blocking changes
- Links to your pages shared in Meta's apps lose their preview.
To block it, add this group to your robots.txt. Meta says this crawler may bypass robots.txt when it performs security or integrity checks.
User-agent: facebookexternalhit
Disallow: /robots.txt only asks. It does nothing against a client that ignores it or only pretends to be facebookexternalhit. Stopping those takes verification at your edge.
facebookexternalhit: common questions
See which bots reach your site, and which of them are who they claim to be.
What is facebookexternalhit?
facebookexternalhit is Meta's link preview crawler. It fetches a page when someone shares its link in a Meta app, to build the preview.
How do I verify that a request is really facebookexternalhit?
Meta says a crawler request comes from Meta if its source IP is on the list this command returns: whois -h whois.radb.net -- '-i origin AS32934' | grep ^route. That list covers Meta's whole network (AS32934), not this crawler alone, and Meta notes the addresses change often. The user agent alone proves nothing: any client can send it.
How do I block facebookexternalhit in robots.txt?
Add a group for User-agent: facebookexternalhit with Disallow: /. Meta says this crawler may bypass robots.txt when it performs security or integrity checks. robots.txt only asks. A client that ignores it, or pretends to be facebookexternalhit, has to be stopped at your edge.
What happens if I block facebookexternalhit?
Links to your pages shared in Meta's apps lose their preview.
Related bots
- Meta-ExternalAgent (Meta): Crawls for training AI models or improving Meta products.
- Meta-ExternalFetcher (Meta): Fetches individual links on behalf of Meta product users.
- Twitterbot (X): Fetches card markup when a link is shared on X.
- Pinterestbot (Pinterest): Indexes pages behind Pins and keeps Pin details up to date.