CAPI (Conversions API)
Server-side event tracking that replaces pixel data lost to ad blockers and iOS.
Conversions API (CAPI) is Meta's server-side event tracking endpoint. Instead of relying on a browser pixel that can be blocked, CAPI sends conversion events directly from your server to Meta's ad platform. Google has a parallel: Enhanced Conversions and Google's Conversion API.
Context
iOS 14+ tracking restrictions, third-party cookie deprecation, and ad-blocker adoption collectively break 20–40% of client-side pixel events. CAPI recovers most of that signal because it runs server-to-server, invisible to the browser.
CAPI implementation via Stape (hosted server-side GTM), self-hosted GCP containers, or platform native endpoints. DIY implementation is rarely the right answer — the compliance and deliverability edge cases are significant.
A DTC brand implementing CAPI alongside the Meta Pixel typically reports 15–40% more conversions than pixel-only — which unlocks higher optimization volume for Meta's ML and often improves reported ROAS and true MER.
CAPI captures conversion signal; it doesn't change attribution. Meta still uses its 7-day-click, 1-day-view model to decide credit. CAPI just stops silently losing events.
Related terms
Services that apply this
More Analytics terms
Incrementality
Measuring how many conversions were actually caused by an ad vs would have happened anyway.
MMM (Media Mix Modeling)
Statistical modeling of marketing impact across channels using historical data.
GA4 (Google Analytics 4)
The current version of Google Analytics — event-based, privacy-aware, BigQuery-native.