Safari Fingerprinting Protections in iOS 12

With the release of iOS 12, Apple introduced major privacy updates to Safari aimed at neutralizing browser fingerprinting and covert cross-site tracking. Browser fingerprinting is a tracking method that identifies users based on the unique combination of their device characteristics, such as installed fonts, hardware specifications, and system configurations. To combat this, iOS 12 deployed system-level standardization and enhanced Intelligent Tracking Prevention (ITP 2.0) to make every user’s device blend into the crowd.

Simplified System Profiles

The primary defense introduced against fingerprinting in iOS 12 was the presentation of a simplified, standardized system profile to websites. Rather than exposing unique device attributes, Safari began sharing only a generic set of characteristics. This approach ensured that an individual iPhone or iPad appeared virtually identical to millions of other iOS devices, eliminating the data variations trackers rely on to build unique identity profiles.

Built-in Font Restrictions

Font enumeration was previously one of the most effective ways to fingerprint a device, as trackers could query the browser to see which custom fonts were installed. In iOS 12, Safari stopped exposing custom or user-installed fonts to web pages. Instead, the browser only presented the standard system fonts built directly into the operating system. Without access to an individualized font list, tracking scripts could no longer differentiate between users based on typography assets.

Elimination of Plugin Identification

Trackers frequently probed browsers to detect installed extensions and legacy plugins to further narrow down a user's identity. iOS 12 reinforced Safari's defenses by preventing web pages from detecting or querying installed plugins. By presenting an identical, clean baseline across all devices, Safari removed yet another variable from the fingerprinting equation.

Enhanced ITP 2.0 and Social Widget Blocking

Alongside passive fingerprinting protections, iOS 12 upgraded Apple’s Intelligent Tracking Prevention to version 2.0. This update targeted active tracking elements such as embedded "Like" buttons, "Share" buttons, and comment widgets from social networks. Previously, these widgets loaded tracking scripts in the background even if the user never interacted with them. In iOS 12, Safari blocked these widgets from accessing cross-site cookies until the user explicitly tapped them and granted permission via a prompt, preventing ad networks from linking off-site browsing history to identifiable user accounts.