XDID, Third-Party Cookies for Google Analytics

Outfox is happy to offer our clients the possibility to use third-party cookies for network tracking using Google Analytics.

Using XDID (cross domain ID), each web browser gets a unique third-party ID. This ID is available to all websites in your network. This makes it possible to track users across different domains.

XDID-domainsXDID is handled as a User ID in Google Analytics. That means that you will continue to collect all data using the first-party cookie normally used by Google Analytics. At the same time, you’ll be able to collect data based on XDID.

With XDID you get the possibility to report on, and analyze, data about your visitors that has not been possible in Google Analytics before now.

Here are a few examples.

Report unique browsers (“users”) in the entire network
Get a deduplicated number of users who have visited at least one site, but possibly several, in the same network using the same browser.

Overlap between websites
Find out how many of users of site-a.com also visit site-b.com. It’s also possible to find out in which order sites are visited in the same network. Find out how different sites assist conversions!

See the effect of marketing on the entire network
If campaign X has resulted in traffic to one of the sites in the network, the resulting sales can be evaluated for the entire network. In other words, the conversion must not have occurred on the site the campaign linked to. This is particularly useful when you have campaign sites under other domain names, which may result in sales on your main site.

Not like cross domain tracking

Google Analytics has long offered cross domain tracking. That’s a technique vastly different than XDID. Cross domain tracking requires that the user clicks links between the sites that you want to analyze together.

Since XDID is based on a third-party cookie, the web browser can be identified uniquely in the network independent of how the visitor reached the sites.

Great coverage

Up to 97% of all sessions can be tied to a XDID. How large the discrepancy is depends on which web browsers are being used. XDID is not supported by old browsers, such as Internet Explorer 8 and earlier. By using the “User-ID Coverage” report in Google Analytics, you can assess which share of sessions can be tied to XDID.


More information

For more information on how to use XDID in Google Analytics, contact us