Google Signals

Google Signals is data collected from users who are signed in to Google and have turned on Ads Personalization, letting GA4 see activity across their devices.

You enable Google Signals in admin, and GA4 starts associating sessions from the same signed-in Google account even when they happen on different devices. That powers cross-device reporting, demographic and interest breakdowns, and remarketing audiences built from those signed-in users.

A user browses your product on their phone during lunch, then buys on their laptop that night. Without Signals, GA4 counts two separate users. With Signals, if that person is signed in to Google on both, GA4 can recognize it as one user completing one journey across two devices.

Signals no longer feeds the reporting identity. As of February 12, 2024, Google removed Google Signals from the reporting identity, so it stopped being used to deduplicate users in standard reports; demographics and interests now come from modeling instead. Turning Signals on is also the fastest way to trigger data thresholding, so weigh the cross-device benefit against the reports it will start hiding.

Still useful for audiences and demographics. No longer the thing stitching your users together.