What is facebookexternalhit?
facebookexternalhit is Meta's web crawler that fetches content from apps or websites shared on Facebook, Instagram, or Messenger to gather, cache, and display information like titles, descriptions, and thumbnail images. Agent Analytics can track when it visits your website.
Overview
| Operated By | Meta |
| Source | Official Website |
| Expected To Follow Robots.txt | No |
| Insights Last Updated | August 11, 2026 |
Do you operate this agent? Contact us to suggest an update.
Category
Expected Behavior
facebookexternalhit usually makes a single request within seconds of a URL being shared, without crawling further. Traffic rises and falls with sharing activity, so a widely circulated link can produce a sharp burst of fetches.
facebookexternalhit's User Agent
| User Agent | Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1) AppleWebKit/601.2.4 (KHTML, like Gecko) Version/9.0.1 Safari/601.2.4 facebookexternalhit/1.1 Facebot Twitterbot/1.0 |
How To Block facebookexternalhit With Robots.txt
Add this rule to your robots.txt file to request that facebookexternalhit not access your website, or use Automatic Robots.txt to request the same of all fetchers at once. You can customize which pages are blocked by swapping out / for a different path.
User-agent: facebookexternalhit # https://knownagents.com/agents/facebookexternalhit
Disallow: /Global Statistics for facebookexternalhit
As of August 11, 2026, this data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the top 1000 websites and their robots.txt files.
Robots.txt Blocked Percentage
Country of Origin
Robots.txt Blocking Trend
10% of top websites block facebookexternalhit in their robots.txt files.
Overall Fetcher Traffic
2.6% of all web traffic came from fetchers.
Top Visited Website Categories
The types of websites most frequently visited by facebookexternalhit.
Frequently Asked Questions
Should I Block facebookexternalhit?
Usually not. Blocking facebookexternalhit may leave shared links without a title or image, making them less inviting to click. If it begins fetching at unexpected volume, try rate limiting before blocking it outright. For context, 10% of the top websites we track currently have robots.txt rules for facebookexternalhit.
Does facebookexternalhit Follow Robots.txt Rules?
No. facebookexternalhit is not expected to follow robots.txt directives, so a disallow rule only communicates your preference. Enforce the block with firewall or server rules, then use Agent Analytics to verify that its requests stop.
Does facebookexternalhit Access Private Content?
No. facebookexternalhit has no credentials and should access only the public URL and assets needed for a preview. It does not continue through the rest of your site.
Why Is facebookexternalhit Visiting My Website?
Someone shared a link to your page. facebookexternalhit fetched it to build a preview card, and each new share may trigger another request. A spike often means your content is circulating more widely.
How Can I Tell if facebookexternalhit Is Visiting My Website?
Agent Analytics tracks visits from facebookexternalhit and every other known AI agent, crawler, and scraper, then authenticates each visit using facebookexternalhit's published verification method. You can also check your server logs for requests whose user-agent string contains "facebookexternalhit". Look for a page and its preview assets being requested without follow-up navigation. A matching log entry alone is not proof because any bot can claim to be facebookexternalhit.