Safari tightens grip on third-party interactions

Apple’s Safari browser, long known for its emphasis on user privacy, is further restricting data collection methods. The move has sparked frustration, particularly due to Apple’s lack of communication about the change, which will impact the architecture of numerous websites.

What’s happening. Apple is closing a loophole that allowed websites to pass off third-party partners as first-party cookies. First-party cookies enable websites to recognize returning users, allowing them to avoid logging in each time they revisit a publisher’s site.

Why integration is key. Many websites collaborate with third parties to improve functionality, using tools like Google Analytics, Adobe Analytics, and content hosting services. They want these partners to track their audiences, but third-party cookies have not been available since Safari deprecated them in 2017. Consequently, websites have devised various methods to disguise third-party cookies as first-party cookies, with Safari attempting to counteract these techniques over the past few years.

In October 2022, an Apple engineer posted on GitHub about the company’s intention to limit one such cloaking technique. The post explained that Apple would compare the IP address of the incoming response with the IP address of the main resource response. If the addresses are mostly different, the cookies can only last for seven days before being destroyed, thus limiting the data usage and inferences that can be made.

Mums the word. Apple never published an official blog post about the change or specified when it would be implemented. Anton Lipkanou, president of analytics-focused agency Delve, stated that the change is already active and causing anomalies in website data. However, Jen Simmons, Apple Evangelist on the web developer team for Safari & Webkit, tweeted on April 11 that the change had not been implemented. Apple has not provided any comments.

Ad-tech executives’ dissatisfaction with the change stems from Apple’s limited communication about it, given its impact on many websites’ architecture.

Publishers and advertisers may be affected as sites working with multiple third parties using this technique might need to revise their website operations, according to Loch Rose, chief analytics officer at Publicis-owned data firm Epsilon. He added that many sites with a majority of their traffic from Apple users could lose significant functionality.

Why we care. The changes in Apple’s Safari browser make it harder for websites to work with third-party services like Google Analytics, can directly impact advertisers’ and brands’ ability to gather and analyze user data. It can hinder their capacity to tailor marketing campaigns, target specific audiences, and measure the effectiveness of their advertising strategies. In turn, this may lead to a reduced ROI and diminished overall performance for their marketing efforts.