facebook is a single-page fetcher operated by Meta. It fetches one page (or a small set) when triggered by a user action, typically a link being shared on social media, a messaging app, or an RSS reader.
Volume tracks shares and clicks rather than crawl schedules. A trending link can produce a sudden spike, but facebook will not crawl the rest of your site.
Blocking it usually means the link previews on the corresponding platform stop showing your title, image, and description.
See facebook on your own site
Match the User-Agent header on incoming requests against the pattern below.
regex
Verify by IP
For higher confidence, also verify the source IP against the operator's published ranges. UA strings can be spoofed; IP ownership is harder to fake.
Renders JavaScript
No
IP verification
Published IP ranges
Crawl frequency
Per user action
Honors robots.txt
Yes
Honors Crawl-delay
Varies
Meta runs 16 bots in total. Each one is a separate user-agent so you can allow or block them independently.
Link Unfurler
9Training Crawler
3Live-Fetch AI
2AI Search Index
1SEO Crawler
1Should I let facebook through?
In most cases, yes. Fetchers power link previews and feed readers. Blocking breaks the user experience on social and messaging platforms. If volume gets noisy, rate-limit it before you block it outright.
Does blocking facebook affect my Google rankings?
No. facebook is not a search-engine crawler. Your ranking on Google or Bing is unaffected by what you do here.
How do I confirm a request is really from facebook?
Two checks. The User-Agent header should match a known facebook string, and the request's source IP should fall inside Meta's published ranges. The User-Agent alone is trivially spoofable, so the IP check is what gives you confidence. Meta publishes the ranges so you can validate at the CDN or edge.
What breaks if I block facebook?
Link previews, embeds, and unfurls on whatever surface facebook feeds will stop rendering. Users sharing your URLs into Meta will see a bare link instead of a rich card. Usually that's the first thing people regret blocking.
How is facebook different from Meta's other bots?
Meta splits work across multiple user-agents so site owners can decide on each one independently. Training crawlers, live-fetch agents, search indexers, and agentic browsers each get their own name. Worth scanning the rest of the Meta family above to see which ones actually matter for your site.
What's the cleanest way to control facebook?
Two layers. Robots.txt for the polite crawlers that read it, and rules at your CDN or edge for the ones that don't. Rankly's Agent Experience handles both from a single config, so you can allow, block, rate-limit, or serve a stripped-down version per bot. Agent Analytics handles the observation half so you know which bots are actually worth a rule.
Verify everything above against the operator's own documentation.