What is a User in Google Analytics 4?
One of the most fundamental concepts in Google Analytics 4 is the idea of a "user," but it’s also one of the most misunderstood. If you've recently migrated from Universal Analytics, you’ve probably noticed that the numbers don’t quite add up the same way. This article will break down exactly what a user is in GA4, how Google identifies them, and the important differences between metrics like 'Total Users' and 'Active Users' that are crucial for accurate reporting.
The Big Shift: Why "Users" Are Different in GA4
To grasp the concept of a user in Google Analytics 4, it helps to first understand the old model. Universal Analytics (the previous version of GA) was built around sessions and cookies. A user was essentially a unique browser cookie. This created a significant problem: if one person visited your website on their laptop and then again on their phone, Universal Analytics would count them as two separate users. It tracked devices, not people.
GA4 flips this model on its head. It’s built around events and users, a structure designed to provide a more holistic view of the customer journey across different devices and platforms (like your website and your mobile app). The goal is to get closer to tracking a single, unified individual's journey. At its core, a user in GA4 represents an individual person interacting with your business, not just a browser cookie.
How GA4 Identifies a User
Because the goal is to stitch together a person's activity across devices, GA4 uses a sophisticated, multi-layered approach to identity. It tries to use the most accurate method available, moving down a hierarchy if the better options aren't present. This happens in the background, but understanding the pecking order helps you see why your user data is more - or less - accurate.
User-ID: This is the gold standard. A User-ID is a unique, non-personally identifiable ID that you assign to a user when they log into your website or app. Because this ID remains the same whether they're on their phone, tablet, or desktop, it allows GA4 to accurately stitch their entire journey together. For businesses with user accounts (like e-commerce sites or SaaS platforms), enabling User-ID is the single best thing you can do for accurate reporting.
Google Signals: If a User-ID isn’t available, GA4 checks for Google Signals. This uses data from users who are signed into their Google accounts and have turned on Ads Personalization. Because Google knows this user across their different devices, it can associate their activity with your site without needing a formal login on your end. It’s a powerful way to get cross-device insights, but it only applies to a subset of your users who have opted in.
Device ID: This is the final fallback. If neither User-ID nor Google Signals are available, GA4 resorts to the classic method: the Device ID. For websites, this is the Client ID stored in the first-party
_gacookie in the user's browser. For mobile apps, it's the App-Instance ID. This is the least accurate method, as it brings back the old problem of counting one person on three devices as three separate users.
GA4 uses these methods to create a "blended" reporting identity, trying to give you the most accurate and de-duplicated user count possible.
GA4's Key User Metrics, Explained
One of the most confusing parts of GA4 is seeing several different "user" metrics in your reports. They aren't interchangeable and each tells a different story about your audience.
Total Users
What it is: Total Users measures the total number of unique users who have logged any event on your website or app within the selected date range. This count is based on their unique User-ID or Device ID. It’s the broadest measurement of audience size.
How to think about them: Think of this as your total reach. If someone lands on your site even for a second, they are included in this metric. It answers the question, "How many distinct individuals interacted with my site in this period?" They might have visited once or a hundred times, they are still counted as one "Total User".
Example: A person lands on your blog, reads one paragraph, and leaves. They’ve logged a page_view event, so they are counted as one Total User.
New Users
What it is: New Users counts the number of users who interacted with your site or app for the first time. GA4 identifies this based on the automatic collection of a first_visit (for websites) or first_open (for apps) event.
How to think about them: This is your customer acquisition metric. It tells you how well your marketing and SEO efforts are doing at attracting a completely new audience. It answers the question, “How many brand-new people did we bring to our site during this period?”
Example: Someone clicks on your Facebook ad and lands on your marketing site for the first time ever. A first_visit event is logged, and they are counted as one New User. If they return the next day via a direct link, they will not be counted as a new user again.
Active Users
What it is: This is the primary user metric used in most standard GA4 reports. An "Active User" is a unique user who either has an 'engaged session' OR is a new user who GA4 logged a first_visit event for.
An 'engaged session' is a session that:
Lasted 10 seconds or longer (this is the default and can be changed in settings) OR
Had at least one conversion event OR
Had two or more page or screen views
How to think about them: Active Users is your primary engagement metric. It filters out the "accidental" visitors who bounce immediately. A high number of Total Users, but a low number of Active Users might signal that you’re getting a lot of irrelevant traffic that isn’t sticking around. It's the metric GA4 trusts most to represent your valuable audience.
Example: Someone visits your home page, stays for five seconds looking for something, and hits the "back" button. They are a Total User but not an 'Active' one. Someone else lands on your homepage from Google Search, spends twenty seconds viewing a few other pages on your site, and is counted as an 'Active User' (and a Total/New user).
Where to Find and Use These Metrics in Your Reports
Now that you know the difference, you can leverage them to get better insights from your GA4 account. Here’s where to look.
Reports Snapshot & Realtime
The main ‘home page’ of your reports, the Reports Snapshot dashboard, prominently features Users. This card refers to Active Users. The RealTime report also shows these Users in a similar light when showing you who's currently on your website.
Life Cycle & User Reports
These user metrics are available in almost every standard report in GA4 - especially under the Acquisition and Engagement Reports on your sidebar. For example:
User acquisition report: This report focuses on New Users, helping you see which marketing channels (e.g., Organic Search, Paid Social) are best at bringing first-time visitors to your site.
Traffic acquisition report: This report is session-based and focuses on the Users metric as the main user metric. You might find you can analyze either by sessions or users, depending on your company structure. Both provide incredible insights regardless.
Switching between these reports helps you distinguish between channels that drive initial awareness (high New Users) and channels that drive ongoing engagement (high Active Users).
Explorations
The standard reports are just the beginning. The real power of GA4 lies in the Exploration builder section. Here, you can build completely custom reports, Funnel analyses, and path journeys, dragging and dropping each of the user metrics - Total, New, and Active - as you see fit.
For example, you could easily build a freeform exploration to compare the number of total users from the United States with the number of Engaged/Active users. This shows you not just how many people you reached, but how many were genuinely interested.
Final Thoughts
Wrapping your head around "user" metrics in an analytics platform like Google Analytics 4 is fundamental to understanding both acquisition and engagement. By moving away from vanity metrics tied to device-bound cookies and towards a model focused on individuals interacting across those devices, you gain a much more accurate picture of how people are actually interacting with your business.
Of course, true understanding often requires combining this data with information from other touchpoints across your stack. This process of cross-checking your GA4 numbers against your CRM, advertising platforms, and sales tools can be incredibly manual and time-consuming. We built Graphed to solve that problem by connecting your data sources and letting you ask questions in plain English. You can simply ask, "Show me all the new users we attributed to Facebook campaigns, then filter for those that converted to HubSpot and Salesforce in the past 30 days," and instantly get the answer back as a live dashboard.