In 2017, Apple introduced the first version of ITP to limit cross-domain tracking by degrading Javascript (JS) third-party cookies and leaving only a 24-hour window to exploit them.
In June 2018, Apple released ITP 2.0 which natively blocks JS third-party cookies used for advertising measurement and targeting purposes on the latest versions of Safari (iOS, iPadOS & Mac).
In February 2019, Apple revealed ITP 2.1 which applies to iOS 12.2 and Safari 12.1. It changes the lifetime of JS first-party cookies and caps it to 7 days, on top of the blocking of third-party cookies by default set by ITP 2.0.
Announced in April 2019, ITP 2.2 cuts the JS first-party cookies data lifetime from 7 days to 24 hours for pages where the URL contains user ID parameter. Learn more