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Intelligent Tracking Prevention (ITP) 2.1 - Further limitations to your tracking

As many of you know, Safari recently announced the release of a new version of their Intelligent Tracking Prevention (ITP 2.1) to be rolled out to all devices using Safari by the end of March 2019. This further reduces trackers’ abilities to identify users across sites. If you have never heard of ITP before; we published an article during its first days that will help you understand ITP.

Why is ITP 2.1 happening?

About a year ago, ITP 2.0 was released by Safari on their browsers immediately partitioning cookies for domains determined to have tracking abilities and removing the previous window of 24 hours after user interaction for general cookie access. Instead, access to 3rd party cookies could be obtained through the Storage Access API. To mitigate this, some vendors started leveraging 1st party cookies to carry out cross-site tracking.

However, this workaround prompted Safari to work on a new update to tackle the use of 1st party cookies (typically used to store anonymous IDs or carry out site performance analytics) and ITP 2.1 has now been released to put an end to this approach.

What are the changes in ITP 2.1? 

This new version of ITP removes any support of partitioned cookies (as of ITP 1.1 these are session cookies that are not persisted). In addition, 3rd Party Cookies classified with cross-tracking capabilities will be forced to use the Storage Access API. The new timeline for classified domains’ cookies and site data is as follows:

ITP 2.1 cookie lifetime graph

However, the scariest change with this new version is the cap of 1st party cookies to 7 days of storage. This means that every persistent 1st party cookie set through the document.cookie method will be forced to have a 7 day expiry date. Therefore, this update will not only affect cross-site tracking, but it will hinder performance analysis as well as optimisation for any site whose userbase return frequency falls outside the new 7 day window, as some users won’t be identified as the same person across different sessions.

How bad is it for the GMP?

Firstly, let’s make something clear: this will only affect Safari and then, only users who don’t return to the site within a 7-day window.

Impact on Analytics/Optimize reporting:

  • Mostly limited to acquisition reports and user driven metrics:
    • Anyone who returns after 7 days would be counted as a new user rather than the 2 years or cookie deletion window (this translates into more user numbers and losing previous source/medium data).
    • Conversions as a metric won’t be affected but Multi-Channel Funnels (MCF) and attribution will obviously be compromised.
    • Calculations on Life Time Value (LTV), cohorts, etc. will also be impacted.
  • Worry not, session-based metrics without acquisition will not be impacted.

Impact on Google Ads/SA 360/Audiences:

  • Both Audiences and Remarketing Audiences will be affected regardless of the platform on which they were created.
  • Optimize audiences will also be impacted, both from GA used for targeting and standard test variation audiences. Hence, users returning to the site on day 8 after their last session may receive a different experience if a test they were included in is still running.
  • It will arguably have less of an impact on Search. This is because the majority of conversions through PPC happen within the 7 day prescribed cookie duration. However, this is not the case for all advertisers, as goods/services with longer consideration phases will likely see the user journey carry on past this point. In order to facilitate this, Google Ads and SA360 will be modelling Safari conversions occurring past the 7 day mark.
  • It is expected that higher discrepancies between GA conversion values and Google Ads/SA 360 will be generated.


  • There are no official workarounds yet although Google have engineering teams currently evaluating potential options to mitigate the impact.
  • Some people have started coming up with possible solutions that involve using the Local Storage functionality of browsers. However, before adopting this approach, it is strongly advised that anyone considering this solution double-checks with their privacy/legal team first. Finally, it is worth mentioning that Safari will likely release a new version of ITP to block this approach in the future if its use becomes widespread.
  • In order to ensure measurement is minimally affected, there are some other actions that need to be taken by advertisers on SA360. If you’ve already made these changes to cope with previous iterations of ITP, the good news is that there are no new changes that need to be made. If no action has been taken previously, then there are two solutions:
    • If you still have iframe/image tags, the process is a bit complex as you’ll need to generate a new Global Site Tag in Campaign Manager and implement the Global snippet from this across all pages on your site. Then you’ll also need to replace your existing floodlights with the Event snippet generated as part of the Tag.
    • However, if you have Google Tag Manager integrated, the process is much simpler, as you’ll just need to implement the Conversion Linker Tag, and set it to fire on All Pages.


In conclusion…

It will be interesting to see the approach that the leading analytics and marketing companies take to mitigate ITP 2.1. Given that Apple have already implemented changes to target workarounds to previous versions of ITP, there is a very real threat that they will do the same again.  Consequently, any approach they take must appease Apple’s privacy perspective or risk being consigned to another short shelf-life.

This blog will be updated once more information becomes available, so stay tuned!