Apple blocks major ad tech firms in Safari via secret iOS 27 list
Apple’s iOS 27 updates, released in mid‑September, began blocking major ad tech firms from tracking users in Safari. The initial list names The Trade Desk, LiveRamp, ID5, Permutive and Experian’s Audigent as blocked, while rivals such as Zeta’s LiveIntent, Lotame and Yahoo’s ConnectID remain unblocked. When a user opens Safari, the browser stops communicating with the blocked domains, preventing them from collecting data or serving ads.
Apple requires every browser installed on iPhone and iPad to use its WebKit engine, so Chrome, Firefox and others are subject to the same blocklist. The new WebKit code lets Apple add or remove companies from the list without waiting for a full iOS update, although the code has not yet shipped to users.
“What this will allow Apple to do is make this block list dynamic,” Rowena Lam, senior director of privacy and data at IAB Tech Lab and product lead for its Trusted Server initiative said.
Advertising Week New York, a four-day conference that draws nearly 20,000 of adland’s finest, is renowned for on-stage programming tinged with optimism and creator reps angling for their 15 minutes in the spotlight. However, out in the snaking lines outside the conference venue, nearby hotels and dive bars, the talk often circles back to Apple — the biggest brand/provider in the industry — which reopened its war with the digital ad industry just a week before.
What we know
Apple’s iOS 27 updates were released in mid‑September.
The first companies blocked by Apple’s Safari list include The Trade Desk, LiveRamp, ID5, Permutive and Experian’s Audigent.
A test of more than 70 ad tech domains found only the initial handful blocked.
Apple has written new WebKit code that lets it add companies to the blocklist without waiting for a software update.
The new WebKit code has not yet shipped to users.