According to the WWDC announcement in July, Apple will launch a new Advanced Tracking and Fingerprinting Protection (ATFP) feature in Safari. This feature will add several new features to protect user privacy and will have a significant impact on the industry.
This feature is already in the Safari Technology Preview. Based on experience, there is typically a delay of approximately three months between the Technology Preview and the stable version. It is expected to be in the stable version in October.
New Features
There are two main things about privacy:
- Added support for filtering tracking paramaters in links in regular browsing mode. (134226694)
- Added support for preventing fingerprinting for known tracking scripts. (134227067)
The original Apple release record is: https://developer.apple.com/documentation/safari-release-notes/safari-26-release-notes
The corresponding is:
- Link Tracking Protection: Automatically detects and removes ad tracking identifiers (such as gclid, fbclid, msclkid, etc.) from URLs. Previously, this feature was enabled only in Private Browsing mode in iOS 17.
Now, the new version extends this feature to all browsing sessions, ensuring that no additional data is leaked when users click on links.- There are still doubts about this. Some people have tested it in the technical preview version. When using a normal browser, the gclid will still be retained, but it will be removed when opening an email or external click.
- Advanced Fingerprinting Protection: Safari now standardizes device information to reduce the uniqueness of browser fingerprinting (generating a unique user identity based on device configurations such as screen resolution, fonts, and GPU), making browser-based fingerprinting more difficult.
Impact
- Link tracking protection can affect attribution in ads and third-party analytics tools.
- Advanced fingerprinting protection can affect user identification.
How to Fix It
Using GA4 as an example, the way to address link tracking protection is to rename the existing ID, such as gclid, to haranid. Safari will then delete gclid, and your landing page will be
https://yourwesite.com/?haranid=CjwKCAjwtfvEBhAmEiwA-DsKjn4iVaWK4
In the basic GA4 configuration, change haranid to gclid, overwriting page_location. The data sent to GA4 will be the gclid.
GA4 is not useful for advanced fingerprinting and should be ignored.
Referral：https://developer.apple.com/documentation/safari-release-notes/safari-26-release-notes
