Enhanced measurement

Enhanced measurement is a set of switches on the web data stream (Admin > Data streams > stream > Enhanced measurement). When on, the tag listens to the browser and sends events for you:

• Page views (page_view), including an option to fire on browser history changes for single-page apps.
• Scrolls (scroll): fired once per page when the user reaches 90% depth. There is no 25/50/75 option; use GTM or custom code for that.
• Outbound clicks (click with link_url, outbound: true): links to a different domain. Domains in your cross-domain list are not outbound.
• Site search (view_search_results with search_term): triggered by a query parameter such as q, s, search, query or keyword; you can add your own.
• Form interactions (form_start, form_submit), with form_id, form_name, form_destination.
• Video engagement (video_start, video_progress, video_complete) for embedded YouTube players with JS API enabled.
• File downloads (file_download) for links ending in common document, archive, audio and video extensions.

These events and their parameters are reportable without creating custom dimensions, because GA4 knows them. They count toward event limits like any event.

Turn off what you do not need. Form events are the usual problem: on sites with search boxes or newsletter forms in the header, form_start fires constantly and clutters reports; sites with custom form frameworks may get form_submit without a real submission. Video events only work for YouTube iframes, not Vimeo or native <video>.

Enhanced measurement is a good first layer; your own custom events for sign-ups and purchases sit on top of it.