How to Use Facebook Conversion API with Google Tag Manager Server-Side

Frequently Asked Questions
Common questions about "🔴 How to use the Facebook Conversion API with Google Tag Manager Server-Side"
Facebook's Conversion API (CAPI) is an authenticated server-side endpoint that allows sending data directly to Facebook Ads from a server rather than a browser. It's important because it provides more reliable tracking as browser-based tracking faces increasing limitations from privacy regulations, ad blockers, and browser protections.
First, set up a GTM server-side container, then create a GA4 client to claim incoming requests. Next, configure a GA4 tag on your website that sends data to your server container, and finally implement the Facebook Conversion API tag in your server container that forwards this data to Facebook.
Event IDs are necessary to deduplicate events when you're sending data both through the browser-based Facebook pixel and server-side tracking simultaneously. Without event IDs, Facebook would count the same conversion twice, leading to inaccurate reporting.
Google's cloud-based server solution may involve data transfers to non-EU jurisdictions, raising GDPR compliance issues. Additionally, Google as a third-party processor has its own data processing terms that may not align with all GDPR requirements for certain businesses.
You can use EU-based hosting solutions like gdpr-server-tracking.eu that provide GTM server-side containers on servers physically located in the EU (Finland) and operated by EU companies (Hetzner). These solutions offer additional privacy features like parameter filtering and data hashing while maintaining the same functionality.
Google's server-side GTM implementation requires Google Cloud Platform resources which incur costs based on usage. Alternative hosting solutions like gdpr-server-tracking.eu offer competitive fixed pricing models that can be more predictable and potentially more cost-effective depending on your traffic volume.
Yes, you can send custom events like transactions or button clicks to Facebook CAPI through server-side GTM. This requires proper parameter configuration in your GA4 tag and may involve additional setup for personal information like email addresses, which need to be properly hashed.
Facebook recommends implementing both the browser-based pixel and Conversion API in parallel (called 'redundant tracking') to maximize data collection. The browser pixel might be blocked by some users, while the server-side implementation provides a more reliable data stream.