🤖 Overview

Factbot is a legitimate web crawler operated by Meta Platforms, Inc. (formerly Facebook) as part of its third-party fact-checking program, first publicly documented in 2018. Its primary purpose is to automatically retrieve fact-check articles from partner organizations (e.g., PolitiFact, Snopes, AFP) so that Meta can reduce the spread of misinformation on Facebook, Instagram, and WhatsApp by attaching warning labels or reducing the distribution of flagged content. The bot feeds data into Meta’s internal content moderation and fact-checking infrastructure. Official documentation is available at Meta’s Webmasters Guide (developers.facebook.com/docs/sharing/webmasters/crawler).

🌐 Technical Behavior

Factbot performs targeted, high-frequency crawls of fact-checking websites and their RSS feeds, typically requesting 10–20 pages per second per IP when active. It uses HTTP/1.1 and HTTP/2 protocols and honors Cache-Control headers to avoid stale content. The crawler originates from a defined set of IP address ranges published in Meta’s DNS-based asn (AS32934) and can be verified via reverse DNS lookups on *.crawl.facebook.com. Factbot respects the Last-Modified and ETag headers to minimize bandwidth usage. It does not crawl images or scripts unless they are embedded in article text, and it ignores JavaScript-rendered content. The bot explicitly identifies itself via the User-Agent header and a From header containing the contact email [email protected].

📋 robots.txt Compliance

Factbot fully honors robots.txt directives as documented in Meta’s official crawler policy. Site owners can block it by adding User-agent: Factbot to their robots.txt, followed by Disallow: /. Meta also provides a separate user-agent string facebookexternalhit/1.1 for link-share previews, but Factbot is the dedicated fact‑checking crawler and will respect any Disallow rules without exception. Compliance is verified through community testing and Meta’s own transparency reports.

🔍 Detection Indicators

The primary User-Agent string is Mozilla/5.0 (compatible; Factbot/1.0; +http://www.facebook.com/externalhit_uatext.php). Additionally, the bot sends a User-Agent containing Factbot/1.0 and a From header set to [email protected]. The IP addresses always resolve to .crawl.facebook.com via reverse DNS, and the originating ASN is AS32934. Behavioral fingerprints include high request rates to article permalinks and consistent use of Accept: text/html,application/xhtml+xml. Unlike typical browsers, Factbot does not send Accept-Language or Cookie headers.

📊 Data Usage

Collected fact-check articles are ingested into Meta’s automated fact-checking system, which applies machine learning models to match claims made on the platform with verified fact-checker assessments. This data is used to generate warning labels, reduce the algorithmic reach of false content, and inform Meta’s transparency initiatives. The bot does not collect user-specific data nor train generative AI models; it only processes publicly available fact-check journalism for content moderation purposes. Meta’s Fact-Checking Program is described in detail at transparency.fb.com.

⚙️ Rate Limiting Policy

Factbot is rate-limited because its high-frequency requests to fact-checker websites can inadvertently place uncharacteristic load on smaller publishers, especially during breaking-news events. Threshold-based blocking (e.g., after 100 requests per minute) is a standard operational practice to protect origin server resources while still allowing Meta to receive timely fact-checks. Site operators are advised to monitor access logs for Factbot and apply rate limiting if necessary, as documented in Meta’s crawler best practices.

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the bots listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.