iOS 17 and Meta Ads: what it means for your pixel

iOS 17 changes the game

iOS 17 introduced Link Tracking Protection — Safari automatically removes query parameters like fbclid, gclid from URLs after clicks from Mail, Messages, or Safari Private mode. For Meta Pixel, this means that a click from a Facebook advert is no longer linkable to subsequent conversion without additional solutions.

Conversion API (CAPI) as baseline

CAPI sends conversion events directly from the server to Meta, bypassing browser tracking limitations. Setup via:

1. Meta Pixel Helper on client (browser)
2. CAPI via server (Stape.io or own backend)
3. Deduplication via event_id so Meta doesn't count twice

Advanced Matching

Send hashed user data (email, phone) with every event. Meta can thus match users between browser and server signals, even when click attribution is missing.

Modelling

Meta has been doing "modelled conversions" since iOS 14 — estimates of conversions that occurred but couldn't be directly attributed. iOS 17 has advanced these models. In Ads Manager under the "Modelled" column you can see how many are estimated.