Apple has once again reshaped the digital marketing landscape. With the release of iOS 26, Apple has introduced a major change: Safari and other Apple-controlled environments now strip certain click IDs from URLs by default. This shift impacts advertisers, CRM platforms, and attribution providers who rely on these IDs for campaign tracking and measurement. Unlike iOS 17, which only applied stricter tracking limits in Private Browsing Mode, iOS 26 applies these rules universally. Let's break down what changed, which IDs are affected, and what this means for marketers.
What Is the iOS 26 Change?
Apple's update targets tracking identifiers embedded in URLs when users click on ads, links, or emails. These changes apply in environments powered by Apple's WebKit framework, including:
• Safari (iOS & desktop)
• Apple Mail
• Apple SMS
• In-App Browser (WebKit)
What stays the same:
• UTMs remain unaffected
• Analytics IDs mostly work, with minor exceptions
• Custom IDs may or may not survive, depending on implementation
Which Tracking IDs Are Impacted?
As of September 4, 2025, here are the confirmed IDs being stripped:
Impact Overview: Where Tracking Still Works (and Where It Breaks)
Here's a simplified view of the tracking impact:
Key takeaway: Safari remains the central friction point.
How Apple Manages the Blocked ID List
The list of stripped parameters isn't static. According to research (h/t Nejc Zdovc), Apple maintains this blocklist via its WebPrivacy service, which updates dynamically and is cached in WebKit.
• Reference: GitHub – APP Safari Param List
• Reference: PrivacyTests.org
How to Test the Change Yourself
Want to verify what's happening?
• iOS 26: Apple iOS page
• Safari Desktop: Safari Technology Preview
Testing methodology matters—but Apple doesn't publicly share details. Our team conducted live experiments (methods not disclosed for IP reasons) to build the ID list above.
What This Means for Marketers
For marketers and Martech providers, iOS 26 introduces new uncertainty:
• Attribution providers relying on click IDs (e.g., fbclid, gclid) will see gaps.
• Marketing automation & CRM tools like HubSpot, Marketo, and Mailchimp lose some visibility.
• UTM parameters remain reliable (for now), offering a fallback.
• Apple's direction suggests a steady push toward user privacy and away from third-party identifiers.
The big unknown: What will Apple do next?
FAQs: iOS 26 Tracking Changes
Q1: Does iOS 26 remove all tracking IDs? No. Only a curated set of click IDs are stripped. UTMs and most analytics IDs remain unaffected.
Q2: Does this impact desktop Safari? Yes. Both iOS Safari and Safari Desktop apply the new restrictions.
Q3: Will Apple expand the list of blocked IDs? Likely. The list is server-managed, meaning Apple can add more IDs at any time without requiring an iOS update.
Conclusion: Preparing for a Post-Click ID World
Apple's iOS 26 update signals a clear direction: greater control over tracking identifiers. While UTMs still work, reliance on click IDs is riskier than ever.
Marketers should:
• Audit dependencies on click IDs across platforms
• Strengthen UTM tagging strategies
• Prepare for further restrictions from Apple
👉 Stay tuned for our next article in this series, where we'll dive into the Martech impact of iOS 26 and how brands can future-proof attribution.