Conversion API

The Conversion API (industry term; abbreviated CAPI) is a server-to-server interface offered by ad platforms — Facebook, Google, TikTok, Microsoft, and others — that lets advertisers send conversion events directly from a server to the ad platform, without depending on a browser pixel. It exists because ad blockers, iOS privacy controls, Safari’s Intelligent Tracking Prevention, third-party-cookie deprecation, and consent banners all silently drop pixel events.

What each platform calls the Conversion API

Platform	API name
Facebook / Instagram	Conversions API (CAPI)
Google Ads	Enhanced Conversions for Web / Google Ads API
TikTok	Events API
Microsoft (Bing)	UET Offline Conversions / Conversion API
Outbrain	Server-to-Server (S2S)
Taboola	S2S Conversions

The mechanics differ per platform, but the goal is identical: deliver a structured server-side event with hashed user identifiers, an event name, a value, and the parameters needed for attribution and modeling.

How AnyTrack uses the Conversion API

AnyTrack sits between your funnel and your ad platforms and wires up each platform’s Conversion API automatically when you connect the integration — there is no per-event mapping to maintain. Every conversion runs through five steps:

Collect — the Tracking Tag gathers first-party data client-side; server-side sources (Shopify webhooks, affiliate postbacks, CRM webhooks) are collected directly.
Attribute — every event is stitched to the original Click ID.
Enrich — customer data is normalized and hashed with SHA-256 per each platform’s spec, with the platform’s own click ID and the metadata that drives Event Match Quality.
Deduplicate — a shared event ID prevents double-counting when the same conversion arrives from multiple sources.
Distribute — the same enriched event is fanned out in real time to every connected platform’s Conversion API.

How the Conversion API differs from similar terms

Tracking Tag — client-side script vs server-side delivery to ad platforms.
Server-Side Tagging — the Conversion API is the channel (the platform endpoint); server-side tagging is the practice of firing to it from a server.
Server-Side Tracking — the Conversion API delivers conversions out to ad platforms; server-side tracking captures them in to AnyTrack — opposite directions.
Outgoing Webhook — CAPI targets ad platforms with hashed identifiers; an outgoing webhook sends the raw event+attribution payload to any endpoint.
Event Match Quality — a match score for a delivered event, not the delivery channel.

Frequently asked questions

FAQ was last reviewed on 2026-06-24

Is CAPI a Meta-only thing?

No. Conversion API is the umbrella for every ad platform's server-side endpoint. Facebook and Instagram call it the Conversions API (CAPI), Google Ads uses Enhanced Conversions for Web, TikTok the Events API, and Microsoft UET Offline Conversions. AnyTrack maps each event to the right format per platform.

Do I still need the browser pixel if AnyTrack sends via the Conversion API?

In most cases yes. The pixel adds session context (such as the fbp and fbc cookies) that raises Event Match Quality. AnyTrack assigns a shared event ID so the ad platform deduplicates the pixel and CAPI events into one conversion.

How much does the Conversion API recover versus the pixel alone?

For most accounts, adding the Conversion API recovers roughly 10–30% of attributed conversions that the browser pixel never saw — and the recovered events tend to be the highest-quality ones.

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