ITP (Intelligent Tracking Prevention)

What is ITP (Intelligent Tracking Prevention)?

ITP is a privacy feature in WebKit that powers Safari’s tracking protection. Apple introduced it in 2017, and it uses an on-device machine-learning model to classify which domains are capable of tracking users across sites. Classified domains have their third-party cookies blocked, and since 2020 Safari blocks all third-party cookies by default. ITP also caps the lifetime of first-party cookies set client-side via document.cookie to 7 days — and as low as 24 hours when a user arrives via a link carrying tracking parameters from a classified domain.

Why does ITP (Intelligent Tracking Prevention) matter?

A large share of your visitors use Safari, especially on iPhone. Because ITP targets JavaScript-set cookies, the data that pixels and analytics tools store often disappears after just a few days. This breaks attribution and conversion tracking over longer windows: a customer who clicks an ad and buys two weeks later may never be tied back to the original campaign. The result is understated ROAS and budget misallocated across channels.

Common use cases

• You see fewer conversions in Meta and Google than in Shopify’s own sales figures.
• Attribution windows of 14–30 days report artificially low numbers because cookies expire too early.
• Retargeting lists shrink because users are “forgotten” after 7 days of inactivity.
• You are deciding whether server-side tracking should supplement your client-side pixels.

Shopify perspective

Shopify Customer Events (the Web Pixels API) runs client-side in a sandbox and is therefore still affected by ITP. The real fix is to send events server-side: Meta’s Conversions API and similar server integrations set cookies via HTTP headers from your own domain and avoid the 7-day cap. Combine both, and lean on Shopify’s native Meta and Google channels so you capture the conversions a pure pixel setup loses in Safari.