Safari's Intelligent Tracking Prevention (ITP) uses machine learning running directly in the browser to identify advertising networks and data companies that track users across different websites, and then blocks or limits their ability to do so. First introduced in September 2017, ITP has been updated continuously and now blocks third-party tracking cookies entirely by default.

ITP uses a machine learning classifier — a model that sorts inputs into categories — to analyze which internet domains are being used to follow users around the web. If a domain is identified as a tracker, Safari restricts how long its cookies can persist and blocks it from operating across different sites. This approach differs from a simple blocklist because the classifier learns patterns on-device without sending browsing history to Apple. ITP has had major downstream effects on digital advertising: it has significantly reduced the ability of companies like Facebook and Google to build behavioral profiles of Safari users. Advertisers and analytics companies have had to adapt their attribution and targeting methods as a result.