Safari 17's Hidden Curveball: When ITP Collides with Service Workers

As a director at Kedos Consulting, I've seen my fair share of browser quirks, but our recent discovery with Safari 17 caught even me by surprise. We've uncovered what appears to be an undocumented issue that's causing havoc for web applications using service workers, particularly those relying on analytics.

The Unexpected Safari Saga

It all started when we noticed something odd happening with one of our major e-commerce clients in the Netherlands. Google Analytics was showing a dramatic drop in traffic, but only for Safari 17 users. Digging deeper, we found ourselves tumbling down a rabbit hole of browser behavior that no one seemed to be talking about.

Here's the gist of what we found:

• Safari 17 seems to be applying its Intelligent Tracking Prevention (ITP) rules to service worker traffic in ways we haven't seen before.
• This is causing certain resources to be blocked, with analytics and tracking scripts taking the biggest hit.
• The result? Severely underreported user activity in tools like Google Analytics.

Why You Should Care

If you're in web development, especially if you're working with service workers or rely heavily on analytics, this Safari 17 issue could be silently skewing your data. And let's face it, in our data-driven world, that's a problem you can't ignore.

I've written up a detailed analysis of this issue on the Kedos Consulting blog. If you're curious about the nitty-gritty details and want to know how this might affect your projects (and what you can do about it), I encourage you to check it out.

Read the Full Technical Breakdown on Kedos Consulting

Stay ahead of the curve. In our fast-paced tech world, knowing about these hidden browser behaviors can make all the difference in keeping your web applications running smoothly.