FBCLID (Facebook Click ID)

FBCLID (Facebook Click ID) is Meta's equivalent of Google's gclid. When users click Facebook or Instagram ads, Meta appends fbclid parameter to landing page URL. Example: yoursite.com/?fbclid=ABC123. The Pixel reads this parameter to match conversions to ad clicks. How it works: User clicks ad → Meta generates fbclid → User lands on site → Pixel reads fbclid → User converts → Pixel sends fbclid with conversion event → Meta attributes to specific ad. Important: fbclid is different from fbp (browser cookie) and fbc (click cookie). All three are used together for attribution. Issues: URL shorteners may strip fbclid, redirects can lose it, and some CMSs block it. Ensure your website preserves fbclid parameter through all redirects and page loads.