Full Answer

Safari's ITP cookie restrictions are not optional privacy settings — they are architectural decisions embedded in the WebKit rendering engine that Apple mandates for all browsers on its platforms.

On macOS, Safari is the default browser and holds approximately 20% of desktop browser market share in most Western markets. Every Safari user on macOS runs ITP with the seven-day cookie cap active. There is no Safari preference to disable it. Users who want longer cookie lifespans must switch to a different browser entirely.

On iOS and iPadOS, the impact is significantly larger. Apple requires all browsers on iOS to use the WebKit rendering engine — Chrome on iOS, Firefox on iOS, and every other browser on iPhone and iPad are WebKit browsers under the hood. This means the seven-day cookie limit applies not just to Safari but to every browser on every iPhone and iPad, regardless of which browser icon the user taps.

The 24-hour restriction is even more aggressive. When Safari classifies a referring domain as a tracker — using machine-learning classification that evaluates cross-site request patterns — cookies set by JavaScript after navigating from that domain expire in 24 hours instead of seven days. This means a visitor who clicks a Facebook ad and lands on your WooCommerce store has just 24 hours before their attribution cookie expires.

For WooCommerce stores, the practical impact is straightforward: any customer journey that spans more than seven days — or more than 24 hours from an ad click — breaks client-side attribution completely. Server-side cookies set via HTTP headers from a first-party domain are not subject to these restrictions, which is why server-side tracking preserves full cookie lifespans where client-side JavaScript cannot.