GA4 Landing Page (not set)
What the heck does landing page (not set) mean?
In most cases, landing page (not set) is nothing to worry about. However, first to understand (not set), we have to understand what a session is in GA4.
In Google Analytics 4, sessions are created when a user “opens your app in the foreground or views a page or screen and no session is currently active (e.g. their previous session has timed out).” A Sessions default inactivity timeout is 30 minutes.
Entrances vs. Landing Pages
Entrances are the count of times the first event in a session happens on a page. Landing pages are the page paths themselves. The biggest difference is that entrances are a metric, and landing pages are a dimension. Metrics are typically quantitative, meaning they’re a number, (100 entrances) dimensions are often strings, (/contact-confirmation landing page) the most common example of a dimension is the “event_name” property.
So what about (not set)?
What (not set) is actually telling you, is that there was an event on a page that happened without a landing page dimension set. How can that happen? It can happen due to misconfigured analytics tags, user ad blockers, filters, (internal ip filter?) and a common reason we’ve seen is a simple session timeout. Sometimes users will step away or leave a tab open on their computer for an extended period of time. When that user comes back they may fire an event, such as a scroll event, before an actual page_view event. This can cause a landing page (not set) entry in your analytics reports.