What iOS 27’s Safari tracking restrictions block

WebKit’s October 19, 2026, explanation says Safari and WebKit block network access to identity-resolution infrastructure in iOS 27, iPadOS 27, macOS 27, and visionOS 27. The restriction targets a third-party tracking method, not a website’s own personalization.

How identity resolution tracks people across sites

Identity resolution lets a third party connect activity tied to an identifier, such as an email address, across websites or devices. In WebKit’s example, someone enters an email address to log in or sign up. A third-party service uses it to create a persistent tracking ID, then returns that ID to a webpage. The service can use the ID to match activity across sites or devices.

WebKit describes the restriction as domain-level network blocking. It says changing the structure of a network request does not, by itself, work around the block.

Which Apple systems WebKit names

WebKit says the restriction applies in Safari and WebKit in iOS 27, iPadOS 27, macOS 27, and visionOS 27. Its description covers iPhone and iPad software, Mac computers, and Apple’s spatial-computing platform.

What the stated target leaves outside its aim

WebKit says first-party personalization is not what its technologies seek to prevent. A website can personalize its own experience for its users; the described target is a central third-party resolver that can connect data across sites, devices, and parties. That distinction does not mean every ad or tracking method is covered by this restriction.

WebKit’s general tracking-prevention policy also lists possible unintended effects of tracking protections, including targeted-ad funding and measurement, federated login, fraud prevention, and bot detection. These are potential effects identified in the general policy. WebKit says it will try to limit unintended impacts while typically prioritizing user benefits when they conflict with existing website practices.

What was reported during the initial rollout

Business Insider reported on October 20, 2026, that Apple had initially blocked domains operated by The Trade Desk, LiveRamp, ID5, Permutive, and Audigent during an episode earlier in October. The publication said that a few days after the initial block, Apple restored The Trade Desk’s ad-serving domain while Unified ID 2.0 remained blocked.