Apple Blocks Hundreds of Ad Domains Across All iPhone Browsers

Under iOS 27, Apple blocks a remotely updatable internal list containing hundreds of advertising and marketing domains, extending to customer data management platforms, audience data, demand-side platforms, data brokers, and digital identity infrastructure.

Among the blocked domains is "adsrvr.org" belonging to The Trade Desk, alongside domains of companies such as LiveRamp, ID5, Permutive, Audigent, and the UID2 standard. An engineer from The Trade Desk objected to the blocking of its domain in WebKit's public bug tracker under number 324771, as reported by German outlet Meedia quoting AdExchanger.

Because Apple mandates that all iPhone browsers use the WebKit engine, the restriction is not limited to Safari alone but extends to other browsers. This measure differs from the App Tracking Transparency feature, which requires user consent for tracking, because it cuts off the infrastructure through which ads themselves flow rather than conditioning tracking on consent.

A previous report had noted the suspension of domain "adsrvr.org" on Safari and the addition of several advertising identity companies to the block list. The new report expands the scope to include hundreds of domains and all browsers—not just Safari—leaving regional advertisers and publishers with a narrower ad delivery channel on iPhones.

What do these terms mean?

WebKit: The rendering engine relied upon by Apple in iPhone browsers, which all other browsers are mandated to use.

Data Management Platform (DMP): A system that collects and categorizes audience data for ad targeting.

Digital Fingerprinting: A method for identifying a device through its technical characteristics when standard tracking identifiers cannot be used.

App Tracking Transparency (ATT): An iPhone feature that requests user consent before tracking them across apps.