Meta ads that survived iOS 14.
The iOS 14 update is exactly what broke the Meta pixel for most stores. The Conversions API is Meta’s answer — a server-side channel the browser can’t block. PrestaSignal sends it cleanly, deduplicated against your pixel, with your token kept safely off the page.
The pixel alone is no longer enough
App Tracking Transparency and ad-blockers strip the Meta pixel of a large share of its events. Without them, Meta’s optimisation and reported ROAS drift apart from reality, and your audiences shrink.
Conversions API, deduplicated, token never exposed
PrestaSignal sends conversions through Meta’s CAPI server-side, constructing _fbc from the fbclid click parameter and forwarding _fbp for matching. It adds an external_id (a hashed customer reference) for cross-device matching, and shares an event ID with the pixel so Meta deduplicates the two. Your CAPI token stays strictly server-side — never visible in page source.
What reaches Meta
How Meta Conversions API works on PrestaShop
The module captures each key event on your server and sends it to Meta through the Conversions API — a direct server-to-server channel that App Tracking Transparency and ad-blockers cannot intercept. It builds the _fbc click cookie from the fbclid URL parameter when the shopper arrives from a Meta ad, forwards the _fbp browser cookie, and adds an external_id (a hashed reference to the customer) so Meta can match the conversion across devices and sessions.
If you also run the Meta pixel, both the pixel event and the CAPI event carry the same event ID. Meta uses that shared ID to deduplicate, so a conversion seen by both is counted once — you get the pixel’s richness plus the server channel’s resilience, without inflating results. Throughout, your CAPI access token is used only on the server and is never written into page HTML, so it can’t be scraped from your site.
What the pixel alone misses
App Tracking Transparency strips the pixel of a large share of events from iPhone shoppers.
Browser blockers prevent the pixel from firing at all for a meaningful slice of traffic.
Without _fbc construction and external_id, Meta has fewer signals to match a conversion to a person.
Fewer events means smaller, staler Advantage+ and retargeting audiences to optimise against.
Meta CAPI server-side — questions.
Does this fix the iOS 14 conversion drop?+
It directly addresses it. The Conversions API sends conversions from your server, which App Tracking Transparency and ad-blockers cannot intercept — recovering the events the pixel alone loses on iOS.
Will the pixel and CAPI double-count my conversions?+
No. Both carry a shared event ID, and Meta uses it to deduplicate — so a conversion seen by both the pixel and CAPI is counted once.
Is my CAPI token exposed on the website?+
Never. The token is used only server-side and is never placed in page HTML or any browser script, so it can’t be scraped.
What’s external_id and why does it matter?+
It’s a hashed reference to the customer that helps Meta match conversions across devices and sessions, improving attribution beyond what cookies alone can do.
Do I still need the Meta pixel if I have CAPI?+
You can run CAPI on its own, but pixel + CAPI together is strongest: the pixel captures rich browser context, CAPI guarantees delivery, and the shared event ID deduplicates them. PrestaSignal supports both modes.
How do I verify events are arriving in Meta?+
Meta’s Events Manager has a Test Events tool, and the module supports a test event code so you can confirm server-side events land correctly before going fully live.
Recover the Meta conversions iOS took.
A free teardown shows what your pixel is missing and what CAPI would recover.