Facebook Conversion API (CAPI)

Facebook strongly encourages its advertising customers to use the Facebook Conversion API (CAPI). This article clarifies what the FB Conversion API is and what options there are for its use.

What is the Facebook Conversion API (FB CAPI)?

Facebook tracking for recording visitors, events and conversions for Facebook advertising or retargeting campaigns is based on the Facebook Pixel. This is used on the client side, i.e. sent with the HTML-source-code to the browser, where it then uses JavaScript to send tracking data from the website visitor directly to Facebook.

In principle, that works very well. The problem, however, is that more and more browser providers are starting to block tracking pixels into their browsers. The spread of increasingly aggressive tracking blocker plugins and similar technologies is also increasing. This increasingly prevents the tracking of the Facebook Pixel, in some cases the (blocking) share goes up to 30%.

Facebook has responded by offering a new (additional) tracking option - the Facebook Conversion API (CAPI). This makes it possible to send corresponding tracking data and events to Facebook via an API - i.e. also on the server. This has the advantage that the tracking events can no longer be prevented on the client side (i.e. by the browser). Of course, you still have to comply with the applicable data privacy rules - without a legal basis and without user consent, no personal data should be tracked (or data that allow to identify the visitor).

There is also an article on the Conversion API from Facebook itself:
https://www.facebook.com/business/help/2041148702652965?id=818859032317965

Options for using the Facebook Conversion API

The following options exist to enable server-side Facebook tracking via the Facebook Conversion API (CAPI):

CMS- or Shop-Plugin

Probably the easiest and fastest way to use the Facebook Conversion API is to use a corresponding plugin for your CMS or Shop-System. This is installed quickly, updates itself in most cases and you take advantage of the server-side advantages.

However, the problem here can be the cooperation with the CMP (cookie banner) used. In many environments, the trackings are grouped together in one place (e.g. in the Google Tag Manager) - this can also be a disadvantage because this tracking is then removed there. Furthermore, it depends on the respective plugin which range of functions it supports - so it may be that (depending on the plugin) individual required functions are not available. In most cases, adaptability is also limited.

When using it, it should be noted that the respective plugin takes over both Facebook Pixel and the Conversion API. There should be no separate tracking (e.g. Facebook pixel in GTM, conversion API via plugin). This is important because every event sent receives an event ID - Facebook recognizes that a server-side event (CAPI) was sent again on the client side (pixel) and can “deduplicate” it.

CMS-Plugins

Your CMS is not listed? Please send us the name and link to your CMS and the FB CAPI extension. We are happy to add to this list.

Shop-Plugins

Your shop system is not listed? Then send us the name and link to your shop system and the FB CAPI extension. We are happy to add to this list.

In summary, it is a safe and easy method to use the Facebook Conversion API via a CMS or shop extension. In any case, insofar as the respective plugin offers all the required functions and works together with the consent system used. The biggest disadvantage is the lack of customization.

Using the "normal" (client-side) Google Tag Manager (GTM)

Theoretically, the Facebook Conversion API could also be used using JavaScript (and thus in the Google Tag Manager). However, this hardly has any advantage over the Facebook Pixel, so this variant has a big question mark. We are not (yet) aware of any ready-made solutions.

The only other option using the client-side Google Tag Manager is to send the tracking events indirectly via a web server. For this there are already some providers who provide a web server (for a monthly fee). This receives the tracking events from the Google Tag Manager and then forwards them to Facebook. There is no direct connection between website visitors and Facebook. Depending on the provider, this option can also offer a data protection advantage.

There are also some (few) templates (in the GTM Community Tempate Gallery) to use the Facebook Conversion API, e.g .:

In this case, however, the inquiries are always routed via the web server of a (third-party) service provider, who charges a monthly fee for its offer.

Using the server-side Google Tag Manager (sGTM)

A currently very common way to use the Facebook Conversion API is the server-side Google Tag Manager (sGTM).

There is a ready-made template from Facebook, which uses the events of an existing Google Analytics 4 integration and “translates” them accordingly for your own Facebook events.

The advantage of this solution is that Facebook creates and maintains the template itself - so this should (always) be a very up-to-date and reliable solution. If the sGTM is already in use, this is probably the most sensible solution. Then the FB CAPI is set up and ready for use very quickly.

In his blog, Markus Baersch offers good German-language instructions for setting up the Facebook Conversion API in the sGTM:
https://www.markus-baersch.de/blog/facebook-conversions-api-mit-dem-google-tag-manager-nutzen/

There are good English-language instructions from Simo Ahava:
https://www.simoahava.com/analytics/facebook-conversions-api-gtm-server-side-tagging/

There are also instructions from Facebook itself for this:
Set Up Conversions API for Server-Side Google Tag Manager

If the server-side Google Tag Manager is not yet in use, it must first be set up. This can be a very challenging and time-consuming task (without appropriate experience). The (live) use of the sGTM also incurs monthly costs (between 40 € and several 100 €) for cloud hosting, depending on the traffic. It is true that you can host the sGTM yourself (as a Docker container), but the majority of them probably lack the appropriate options and knowledge.

Using another tag management system

In addition to the Google Tag Manager, there are other tag management systems, for example the tag management of the Adobe Experience Cloud or the Matomo Tag Manager. However, we could only find a ready-made solution for the Facebook Conversion API with Telium's Tag Management, the Facebook Conversions Connector.

Pretty much all Google Tag Manager alternatives are also purely client-side implementations, i.e. they have no server-side components. This may eliminate the advantage of bypassing tracking blocker on the server side. The respective system must also be able to deal with the Consent Management System used, but this should not be a problem for most of them.

Own integration on the web server

If you have the necessary technical knowledge, you can of course set up tracking yourself using the Facebook Conversion API. The use of the Conversion API is very well documented:

https://developers.facebook.com/docs/marketing-api/conversions-api

Some companies or agencies have already created their own tracking setups, which make it easier to add an additional tracking interface. At Tracking Garden, for example, we offer our Tracking Proxy, which even comes with a ready-made interface to the Facebook Conversion API. Please do not hesitate to contact us, if you are interested.

Your own integration is likely to be the most complex of all solutions and requires appropriate know-how. This is also the biggest disadvantage of this variant. Another disadvantage could be that there is an additional load for the web server with the corresponding traffic. Your own integration should also be checked regularly and must be adjusted manually if changes are made.

Despite these disadvantages, there are also some advantages. On the one hand, there are no costs here (except for the hosting fees, which are likely to be due anyway). This also saves you from being dependent on third parties, which also has an advantage in terms of data privacy - you do not need a data processing agreement or information on the website and there is no additional point to which personal data could go. For this reason, this variant is likely to be the most privacy-friendly of all (insofar as one can even speak of privacy-friendly with Facebook tracking).

In addition, your own integration can be individually adapted to the requirements.

Partner-Integrations

Another possibility is mentioned by Facebook, partner integration, see:

https://www.facebook.com/business/help/260370078559247

However, this is not really a further option; rather, partners selected by Facebook support the integration or offer their own systems for a fee or refer to third providers.