facebookexternalua
Facebook external user agent bot
About this crawler
facebookexternalua is a web crawler identified by the regular-expression pattern facebookexternalua in the User-Agent request header. It is categorised as social-preview. Use the regex above to detect, log, allow, or block facebookexternalua traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
No block-rate data for this crawler.
Technical details
- Name
- facebookexternalua
- Pattern
facebookexternalua- Tags
- social-preview
- Reference
- http://www.facebook.com
- Added
- 2026/05/09
- Instances
- 1 known sample(s)
Sample User-Agent strings
facebookexternalua
Block this crawler
robots.txt — disallow facebookexternalua:
User-agent: facebookexternalua
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} facebookexternalua [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "facebookexternalua") {
return 403;
}
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