Intelligent Tracking Prevention (ITP) is a feature built into Safari on Apple devices. Its purpose is to protect user privacy by restricting the cross-site tracking that websites perform through cookies. ITP uses machine learning within Safari to detect cross-site tracking behaviours and block third-party cookies.
While this feature appears user-friendly by design, it makes tracking user activity significantly harder — creating real challenges for marketing and analytics teams.
How Does ITP Work?
ITP works by imposing time restrictions on cookies and other data storage mechanisms in the browser. As a result, user behaviour cannot be tracked over long periods.
Third-Party Cookies
Safari blocks third-party cookies by default. If an advertising or tracking domain sets a cookie outside of your own domain, Safari will not retain it. This prevents cross-site user tracking entirely.
First-Party Cookies
For users visiting a site, first-party cookies created via JavaScript (document.cookie) are stored for a maximum of 7 days. If the user does not return to the site within those 7 days, the cookie is automatically deleted and the user is lost from tracking.
Link Decoration
If a user arrives at a site via a URL containing tracking parameters (such as gclid, fbclid, etc.) and the site stores this information as a cookie, Safari retains that cookie for a maximum of 24 hours. This means a visitor who came through a campaign click and returns the following day will be recognised as a new, different user.
Local Storage
All data stored in the browser outside of cookies — including localStorage and IndexedDB — is also cleared by Safari after a maximum of 7 days.
Safari automatically deletes cookies and other browser data after a set period to restrict user tracking. For example, if a Safari user does not visit a site for 7 days, the browser clears the identity-related cookies for that user. When the same user returns after 7 days, the site treats them as a brand-new visitor because the previously set cookie no longer exists.
This behaviour means user identity cannot be maintained over the long term, and it forces significant changes in traditional web analytics and tracking practices.
Marketing Impact: Conversion Tracking, Retargeting, and Segmentation
The restrictions introduced by ITP directly affect digital marketers' analytics. Issues arise across conversion tracking, retargeting, segmentation, and automation.
Conversion Tracking & Campaign Attribution
Due to the shortened cookie lifespans, the window for attributing a visit to a conversion has shrunk to as little as 24 hours for link-decorated URLs. ITP's link decoration rule effectively reduces the campaign attribution window to just one day. If a user clicks an ad on Safari but completes a purchase a few days later, it may be impossible to connect that initial click to the eventual conversion.
Retargeting
Because visitor data is deleted quickly under ITP rules, building and maintaining accurate audience lists for retargeting campaigns becomes nearly impossible. This makes it significantly harder to serve personalised ads to specific users. When a Safari user returns to your site, the retargeting system may fail to recognise them entirely.
Segmentation
Because ITP makes it impossible to track Safari users' behaviour over time, long-term segmentation and user targeting for Safari visitors is no longer reliable. This makes it difficult to identify loyal customers or returning visitors. Since Safari users frequently appear as "new" users in segment-based targeting, the consistency of marketing messaging is disrupted.
Automation & Personalisation
The continuous resetting of user data means that behavioural context is lost between sessions. This limits automation capabilities such as showing personalised campaigns, custom product banners, or tailored messaging on a user's next visit — creating both inefficiency and a degraded user experience.
The Most Effective Solution for ITP
Marketers and technical teams can adapt to ITP's restrictions through a few key strategies. Here is the most straightforward and effective approach:
Server-Side Tracking
Processing tracking data on the server side is the most effective method for overcoming ITP restrictions. For example, sending analytics or pixel data directly to a server and setting a first-party cookie there can bypass Safari's browser-level deletion rules. In this approach, the cookie is set server-side via a subdomain belonging to your site (for example, cookies.yoursite.com). ITP grants a longer lifespan to first-party cookies that are set server-side rather than via JavaScript.
Summary
Safari ITP has been a pivotal development that forces the marketing world to rethink cookie-based tracking habits. The blocking of third-party cookies and the short lifespan of first-party data require a fundamental rethink of measurement practices in digital marketing. For marketers and technical teams, the answer lies in developing more creative data strategies that respect user privacy — with server-side tracking leading the way.