Meta
facebookexternalhit
facebookexternalhit is Meta's crawler that fetches web pages to generate link previews when URLs are shared on Facebook, Instagram, and Messenger.
Current Rank
#6
Traffic Share
5.34%
Operator
Meta
Category
Social Media Crawler
What is facebookexternalhit?
facebookexternalhit is a web crawler operated by Meta that visits web pages whenever a URL is shared on Facebook, Instagram, Messenger, or WhatsApp. Its primary purpose is to fetch Open Graph metadata (title, description, image) to generate rich link previews.
This crawler has been active since the early days of Facebook. Every time someone shares a link on any Meta platform, facebookexternalhit visits the page to pull the preview information.
Unlike Meta-ExternalAgent, this crawler is not used for AI training. It serves a purely functional purpose: making shared links look good on social media.
How to Block facebookexternalhit
You can block facebookexternalhit via robots.txt, but this is generally not recommended:
robots.txt
User-agent: facebookexternalhit Disallow: /
Blocking facebookexternalhit will prevent link previews from appearing when your URLs are shared on Facebook, Instagram, and Messenger. Links will appear as plain text URLs without images, titles, or descriptions, significantly reducing click-through rates.
Verifying facebookexternalhit Requests
Verify Meta crawlers by checking the source IP against Meta's AS32934 IP ranges. These ranges change frequently, so always check against the current list.
Verification command
whois -h whois.radb.net -- '-i origin AS32934' | grep ^route
facebookexternalhit Technical Details
User-Agent string: facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)
Fetches Open Graph tags (og:title, og:description, og:image)
Visits pages on-demand when links are shared
Caches preview data (use Facebook Sharing Debugger to refresh)
Not used for AI training, purely for link previews
Separate from Meta-ExternalAgent (AI training crawler)
How facebookexternalhit Affects Your Website
facebookexternalhit directly affects how your content appears when shared on social media. Properly formatted Open Graph tags ensure your links display with compelling titles, descriptions, and images.
Blocking this crawler means your links will appear as plain URLs without previews on Facebook, Instagram, and Messenger, which typically results in much lower engagement and click-through rates.
Frequently Asked Questions About facebookexternalhit
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