Overview
FacebookExternalHit is a search crawler from Meta used for search indexing, URL discovery, page rendering, result freshness, and search-quality checks.
Its primary user-agent pattern is facebookexternalhit; related patterns include Meta preview crawler, facebookcatalog; a representative HTTP user-agent is facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php) facebookexternalhit/1.1 facebookcatalog/1.0.
FacebookExternalHit is verified with High confidence. The identity type is Verified Bot, and the evidence basis is official operator documentation.
FacebookExternalHit is marked as respecting robots.txt directives for crawler access control.
FacebookExternalHit should be reviewed against site policy, source evidence, crawl rate, and requested paths before a permanent allow or block rule is created.
Identity
- User-Agent Pattern
-
facebookexternalhit - Aliases
- Meta preview crawler, facebookcatalog
- HTTP Agent Examples
-
facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php) facebookexternalhit/1.1 facebookcatalog/1.0 - Robots Token
- facebookexternalhit
- Identity Type
- Verified bot
- Evidence Method
- Verify FacebookExternalHit by matching `facebookexternalhit` to Meta evidence, then checking reverse DNS, source-network ownership, signed request data, or published crawler documentation when available.
Classification
- Type
- Search
- Kind
- Crawler
- Family
- Meta
- Operator
- Meta
- Company
- Meta
- Purpose
- Indexing
Behavior and handling
- Common Use
- FacebookExternalHit is used for search indexing, URL discovery, page rendering, result freshness, and search-quality checks.
- Detection Notes
- FacebookExternalHit traffic is primarily detected by the `facebookexternalhit` user-agent pattern; related patterns include `Meta preview crawler, facebookcatalog`; a representative HTTP user-agent is `facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php) facebookexternalhit/1.1 facebookcatalog/1.0`. Compare source IPs, reverse DNS, request paths, and crawl cadence with Meta infrastructure before trusting the traffic.
- Respects robots.txt
- Yes
- Spoofing Risk
- FacebookExternalHit has medium spoofing risk because the user-agent can be copied, even when the bot has strong source or documentation support.
- Risk
- Neutral
- Recommended Handling
- Depends
Rules and controls
- Robots.txt Snippet
-
User-agent: facebookexternalhit Disallow: /