It’s been nearly two years since Universal Analytics (UA) sunsetted, marking a significant shift in how we track website traffic and user behaviour. However, I think a lot of us are still confused about how it’s different from the old version and what each metric actually means. Let’s break down what GA4 is, its main differences and the key metrics we recommend you keep a close eye on.
What is Google Analytics 4?
Google Analytics 4 (GA4) is the new and improved version of Google Universal Analytics. It’s all about understanding how people use your website or app in a much smarter way.
Instead of just counting how many people visit your site, GA4 tracks every single thing they do – every click, scroll, video they watch, you name it! This gives you a detailed picture of what people are interested in and how they’re interacting with your content.
The difference between GA4 and Universal Analytics
There are 5 main areas where GA4 significantly differs from its predecessor.
Data Model: UA operates on a session-based model, primarily tracking pageviews within defined user sessions. In contrast, GA4 employs an event-based model, capturing every user interaction as an individual event. This granular approach provides a more comprehensive understanding of user behaviour, including actions beyond simple page views.
Tracking Scope: UA primarily focused on website tracking, with separate configurations required for mobile app tracking. GA4 offers a unified platform for cross-platform tracking, seamlessly monitoring user journeys across both websites and apps within a single property.
Privacy Focus: GA4 places a strong emphasis on user privacy. It incorporates features such as cookieless measurement and machine learning-based insights to provide valuable data while minimising reliance on traditional cookie-based tracking methods.
AI and Machine Learning: UA’s AI capabilities were limited. GA4 leverages the power of AI and machine learning to generate predictive metrics, uncover deeper audience insights, and automate data analysis, enabling more informed and efficient decision-making.
Reporting: UA’s reporting capabilities were primarily focused on traditional metrics like sessions, page views, and user flow. GA4 offers a more flexible and insightful reporting structure, emphasising key areas such as user engagement, conversions, and cross-platform behaviour.
The Key Metrics to track in GA4
With 99 metrics across ten categories, the data available can seem overwhelming, so here are ten core metrics we recommend tracking, no matter your website type.
Active Users: The number of distinct users who visited your website or application. An active user is any user who has an engaged session or if they triggered specific events such as: first_visit, first_open, user_engagement.
Session: The number of sessions that began on your website or application. A session is a period of time during which a user interacts with your website or app. By default, a session ends (times out) after 30 minutes of user inactivity.
Engaged Sessions: The number of sessions that lasted 10 seconds or longer, or had 1 or more conversion events or 2 or more page or screen views. Engaged sessions is the inverse of low engagement sessions.
Bounce Rate: The percentage of sessions that were not engaged sessions. Bounce rate = not engaged sessions / total sessions Bounce rate is the inverse of engagement rate.
Engagement Rate: The percentage of sessions that meet a minimum engagement threshold (e.g., 10 seconds or two page views). Engagement rate = engaged sessions / total sessions (Engagement rate is the inverse of bounce rate).
Average Engagement Time: The average time that your website was in focus in a user’s browser or an app was in the foreground of a user’s device. Average engagement time = total user engagement durations / number of active users.
Key Events: The number of times users triggered a key event. To populate this metric you must mark an event as a key event.
Events Per Session: The average number of events per session.
Session Key Event Rate: The percentage of sessions that converted. Session key event rate = number of sessions in which a key event happened / total number of sessions.
Views: The number of mobile app screens or web pages your users saw. Repeated views of a single screen or page are counted.
New Users: The number of new unique user IDs that logged the first_open or first_visit event. The metric allows you to measure the number of users who interacted with your site or launched your app for the first time.