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Quick answer: The Meta Conversions API (CAPI) sends conversion events from a server straight to Meta, alongside the browser Pixel. Run both, give each event the same event_id so Meta counts it once, and send hashed customer details such as email and phone to raise your event match quality. Then verify everything in Events Manager.
Why the Pixel alone is not enough
The Pixel runs in the visitor’s browser, so ad blockers, privacy settings and slow pages can stop events from reaching Meta. Missing purchases and leads mean Meta has less data to optimise your campaigns. CAPI fills that gap because the server sends the event directly.
Three common ways to set up CAPI
- Platform integration: Shopify and WooCommerce offer built-in or plugin integrations. Quick to start, less control.
- Conversions API Gateway: a Meta-managed server option that mirrors your Pixel events.
- Server-side GTM: the most flexible option, especially if you already send GA4 and Google Ads data through a server container.
Deduplication: the step most setups miss
When the same purchase arrives from the browser and from the server, Meta needs to know it is one event. Send the same event name and the same event_id from both sides. If the IDs do not match, Meta reports the purchase twice and your results look better than they are.
Improve event match quality
Meta matches events to people using customer information parameters. Send what you have, hashed: email, phone, first and last name, city, country, plus the fbp and fbc browser values and the client IP and user agent. Higher match quality usually means better attribution and optimisation.
Test in Events Manager
Use the Test Events tab with a test code to see browser and server events arrive in real time. Check that each event shows as deduplicated and review the diagnostics tab for warnings.
FAQ
Should I remove the Pixel after setting up CAPI?
No. Meta recommends running both together with deduplication for the most complete data.
Which events should I send through CAPI?
Start with the events that matter for optimisation, usually Purchase, Lead, InitiateCheckout and AddToCart.
Is customer data sent in plain text?
No. Personal details must be normalised and hashed with SHA-256 before they are sent.
Need Pixel and CAPI working together? See my Meta Conversion API service.
