Facebook link preview bot
About this crawler
facebook is a web crawler identified by the regular-expression pattern facebook in the User-Agent request header. It is categorised as social-preview. Use the regex above to detect, log, allow, or block facebook traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
0.065%
Technical details
- Name
- Pattern
facebook- Tags
- social-preview
- Reference
- http://www.facebook.com/externalhit_uatext.php
- Added
- 2026/05/09
- Instances
- 1 known sample(s)
Sample User-Agent strings
acebookexternalhit/1.0 (+http://www.facebook.com/externalhit_uatext.php)
Block this crawler
robots.txt — disallow facebook:
User-agent: facebook
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} facebook [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "facebook") {
return 403;
}
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