Apple ITP (Intelligent Tracking Prevention) and iCloud Private Relay aren't the same thing. One deletes your cookies, the other masks your IP. Here's what you actually lose and what server-side can get back.
ITP — Safari Intelligent Tracking Prevention
Safari on both iOS and macOS automatically deletes third-party cookies within 24h and first-party cookies within 7 days if they were set by JS running on a third party (e.g. analytics.google.com or the Pixel).
What you lose with client-side tracking: _ga (after 7 days), _fbp (after 7 days), _gcl_aw (after 90 days). After this expiry the user looks like a new visitor — you won't capture retention, frequency capping, or lookalike audiences.
What server-side can do: the cookies are set by your server via the Set-Cookie header. To Safari they look like "first-party from the same site" → ITP doesn't delete them. The DataNostro Power-Up Cookie Keeper does this automatically.
Private Relay — IP and User-Agent anonymization
iCloud+ users (~10-15% of iOS traffic in the Czech Republic) have their IP routed through an Apple proxy. Your server never sees their real IP — it only sees a regional Apple egress IP.
What you lose:
- Geo accuracy at the city level (you only see the region)
- IP-based fingerprinting for fraud detection
- IP match in Meta CAPI (lowers match quality by ~10%)
What server-side CAN'T recover: the real IP. Apple simply won't send it. Live with it.
What server-side can work around: you make up the match quality in Meta CAPI with other parameters — hashed email, hashed phone, fbc/fbp. DataNostro handles this automatically if you have at least one of these signals in the dataLayer.
Click ID restorer — gclid, fbclid survive
When a user clicks a Google Ad, gclid=XXX arrives in the URL. Without the Click ID Restorer the value would only live until the first navigation event, then ITP would clear it. The Click ID Restorer Power-Up moves it into a first-party cookie via the server, so it survives even the 30-day attribution window in Google Ads.
Realistic numbers
From our onboarding measurements on CZ stores (3M+ pageviews/month):
- Before server-side: Meta event match quality 4.2/10, Google Ads conversions -28% vs real orders.
- After server-side: Match quality 7.8/10 (+85%), Google Ads conversions only -8% vs real (the rest is Private Relay, which can't be recovered).