We currently use gtag.js on the frontend and report conversions through the API Measurement Protocol. This setup works well for us in terms of conversion attribution, as conversions are correctly attributed.

However, we’ve noticed that the conversion events lack important data, specifically the “device” and “browser” information.

According to the documentation (https://developers.google.com/analytics/devguides/collection/protocol/ga4/reference/events#purchase), it’s not possible to manually add this data to the purchase event. The only way for conversions to be associated with the correct session—and thereby inherit details like the device and browser—is by ensuring they share the same session ID. While this method works for attribution (i.e., medium and source are correctly applied), other session data such as device and browser is not being captured.

To illustrate the issue:

• In screenshot1.jpg, you can see the conversions correctly showing the medium and source.
• In screenshot2.jpg, however, the same conversions have “(not set)” in the browser and device columns.

Could you confirm whether it’s possible to include browser and device data in conversions reported via the Measurement Protocol? If yes how to do it?