Inspired by Mozilla’s anti-tracking policy, Apple has now announced updated WebKit Tracking Prevention Policy which details several things including what types of tracking WebKit will prevent, when other tracking countermeasures come into play such as limiting capabilities and informed user consent and how WebKit handles unintended impact of our tracking prevention.
This document describes the web tracking practices that WebKit believes, as a matter of policy, should be prevented by default by web browsers. These practices are harmful to users because they infringe on a user’s privacy without giving users the ability to identify, understand, consent to, or control them.
Apple’s anti-tracking mitigations in WebKit are applied universally to all websites, or based on algorithmic, on-device classification. Apple also mentioned that it will create new web technologies to re-enable specific non-harmful practices without reintroducing tracking capabilities. The following features may not work properly in WebKit based browsers due to this new tracking prevention policy from Apple.
- Funding websites using targeted or personalized advertising (see Private Click Measurement below).
- Measuring the effectiveness of advertising.
- Federated login using a third-party login provider.
- Single sign-on to multiple websites controlled by the same organization.
- Embedded media that uses the user’s identity to respect their preferences.
- “Like” buttons, federated comments, or other social widgets.
- Fraud prevention.
- Bot detection.
- Improving the security of client authentication.
- Analytics in the scope of a single website.
- Audience measurement.