Our Thoughts on Intelligent Tracking Prevention in Safari

1Blocker team spent last week at Apple’s WWDC17 in San Jose, CA. We were excited and intrigued to see Apple announce that Intelligent Tracking Prevention (ITP) is coming to Safari on iOS and macOS. We had a chance to talk to many Apple engineers at WWDC labs and we think this feature is going to make a big impact. In this post, we will share with you what we have learned about ITP and our thoughts on what it means in practice.

What is Intelligent Tracking Prevention?

Intelligent Tracking Prevention is a new feature built in Safari that reduces cross-site tracking by limiting cookies and other website data. Apple uses a machine learning classifier to determine domains that have the ability to track you. This is done by collecting statistics on resource loads and your interactions with websites (taps and text inputs). It’s important to note that all of this happens directly on device and there is no global blacklist stored on a server.

To learn about how Intelligent Tracking Prevention works in detail, read this technical post on WebKit’s blog.

Intelligent Tracking Prevention vs Safari Content Blockers

We asked Safari team engineers at WWDC what is their vision for Intelligent Tracking Prevention and native Safari content blockers (such as 1Blocker). From what we have heard from multiple sources, Apple sees ITP and Safari content blockers as completely separate features that supplement each other. They are not redundant.

ITP and Safari content blockers take different approaches but they are both aimed at protecting user’s privacy. The key difference is that ITP doesn’t block requests sent to trackers like 1Blocker does. ITP just strips cookie and other data from your requests, which means that you won’t get any speed increase and data savings from ITP. And contrary to common misconception, this feature has nothing to do with blocking ads because the appearance of websites stays exactly the same, as Craig Federighi pointed out during the WWDC Keynote.

Content blockers rely on fixed tracker lists (such as EasyList). On the other hand, Intelligent Tracking Prevention automatically creates its own database of trackers personalized for each user’s device. For this reason, ITP can potentially prevent your personal data from being sent to hard-to-detect trackers that haven’t been yet included in common tracker block lists.

So, our recommendation is to use both Intelligent Tracking Prevention and 1Blocker to protect yourself from being tracked on the Web.

Impact of Intelligent Tracking Prevention

The impact of Intelligent Tracking Prevention is going to be huge because it will be enabled by default for hundreds of millions of users very soon.

The success of the web as a platform relies on user trust. Many users feel that trust is broken when they are being tracked and privacy-sensitive data about their web activity is acquired for purposes that they never agreed to. — WebKit.org

In other words, people never agreed to being tracked online and Apple is on the right track to fix this problem. By pushing these updates to iOS and macOS in a few months, Apple may start a bigger shift across the Web to move away from creepy user tracking techniques towards building user trust.