Conversions API (Meta CAPI)

The dominant server-side conversion API for advertisers running campaigns on Facebook and Instagram, with no direct equivalent competitor within the Meta ecosystem

Conversions API (CAPI), developed and maintained by Meta Platforms, is a server-side data integration solution that allows advertisers to share customer actions and conversion events directly from their own servers, CRMs, or data platforms to Meta's advertising infrastructure. Unlike browser-based pixel tracking, CAPI operates independently of browser limitations such as cookie restrictions, ad blockers, and iOS privacy changes (ATT framework), making it a critical tool for maintaining signal fidelity in a privacy-constrained environment. Meta CAPI supports a wide range of event types including web conversions, app events, offline conversions, and CRM data, enabling advertisers to power campaign optimization, audience targeting, and attribution reporting. It is designed to complement — and in many cases replace or supplement — the Meta Pixel, providing a more reliable and privacy-resilient data pipeline. The API supports deduplication logic to prevent double-counting when both pixel and server-side events are sent simultaneously. In the AdTech ecosystem, Meta CAPI has become a foundational component for performance advertisers running campaigns on Facebook and Instagram. Its adoption has accelerated significantly since Apple's iOS 14 ATT changes in 2021, which severely limited mobile tracking. Meta has built a robust partner ecosystem around CAPI, with hundreds of certified integration partners including CDPs, eCommerce platforms, and tag management solutions, cementing its role as a critical measurement and optimization infrastructure layer for Meta's $100B+ advertising business.