Since Safari’s announcement of ITP 2.1 and 2.2 in spring 2019, data driven marketers and analysts have been considering their options. LocalStorage has been a solution adopted by a lot of organizations and data management vendors, but with the latest iteration of Intelligent Tracking Prevention, ITP 2.3, it will soon come to an end.
On 23 September 2019, WebKit announced that they have seen several trackers move from first-party client-side set cookies to alternate storage options such as localStorage, which combined with link decoration allows for continued long-term tracking. WebKit sees it as a ‘continued abuse of link decoration’ and is countering it with the release of ITP 2.3.
Under ITP 2.3, sites that use link decoration will see all their non-cookie website data deleted after 7 days. Combined with the capped expiration of client-side cookies, this means trackers won’t be able to use link decoration combined with long-term first-party website data storage to track users.
ITP 2.3 thereby shuts down one of the workarounds that have been discussed widely in the business, i.e. localStorage. The remaining viable solution is, thus, setting first-party cookies as server-set HTTP cookies. This is also the approach taken by Cookie Saver.
ITP 2.3 is included in Safari on iOS 13, the iPadOS beta, and Safari 13 on macOS for Catalina, Mojave, and High Sierra.