If you manage one of the millions of websites affected by the Google-mandated migration from Universal Analytics (UA) to Google Analytics 4 (GA4), you might be following the best practice of simultaneously running UA and GA4 scripts until you’re ready to adopt GA4 fully. One of the analytics features that needs special attention is cross-domain tracking.
Google Analytics is the most popular tool for understanding how people are finding and using your site. In addition to its standard reports, you can use its User ID feature to get more fine-grained reporting about registered users. This enables you to better measure, anticipate, and meet or exceed your users' needs.