Google Analytics 4 Setup Guide: Understanding Key Metrics

Why Google Analytics 4 Matters

Google Analytics 4 (GA4) replaced Universal Analytics as Google's primary analytics platform in July 2023. If your site was running Universal Analytics and you have not migrated, you have been collecting no data since that date.

GA4 introduces a fundamentally different data model. Where Universal Analytics counted sessions and pageviews, GA4 is built around events. Every user interaction (a page view, a scroll, a video play, a click) is an event. This approach provides much richer behavioral data and works across websites and apps in a single property.

Creating a GA4 Property

Step 1: Set Up an Account and Property

Go to analytics.google.com and sign in. If you are starting fresh, click "Start measuring" and follow the prompts to create an account and a property.

If you already have a Google Analytics account, click the gear icon (Admin) in the lower left, select "Create" under the Property column, and choose "Property" from the dropdown.

Give the property a descriptive name such as "Company Website GA4" and select the correct time zone and currency. These settings affect how reports are displayed and cannot be changed without affecting historical data, so choose carefully.

Step 2: Set Up a Data Stream

After creating the property, you will be prompted to create a data stream. Choose "Web" for a website. Enter your domain name and give the stream a name.

On the next screen, you will see your Measurement ID (formatted as G-XXXXXXXXXX). This is what you will use to install tracking on your site.

Installing the Tracking Code

Option 1: Google Tag (gtag.js) Direct Install

Copy the provided code snippet and paste it into every page of your site, immediately after the opening tag. For most modern websites using a CMS or a template, adding the snippet to the header template file will deploy it site-wide.

Option 2: Google Tag Manager

For sites already using Google Tag Manager (GTM), create a new tag of type "Google Tag", enter your Measurement ID, and set it to fire on all pages. This approach keeps all tracking in one place and does not require code changes for future modifications.

Verifying the Installation

After installing the code, open your website in one browser tab and open the GA4 Realtime report in another. Navigate through a few pages on your site. You should see active users appear in the Realtime report within 30 seconds. If nothing appears after two minutes, check that the Measurement ID in your code matches the one in the property settings exactly.

Understanding Key GA4 Metrics

GA4 introduces several new metrics that replace and improve on Universal Analytics equivalents.

Users and New Users

"Users" in GA4 counts the number of unique browsers or devices that visited your site in a selected time period. "New users" counts devices that visited for the first time. The ratio of new to returning users tells you whether growth is coming from acquisition or from an engaged existing audience.

Sessions

A session begins when a user arrives and ends after 30 minutes of inactivity or at midnight. GA4 counts sessions slightly differently from Universal Analytics, so do not expect numbers to match during a transition period.

Engagement Rate

Engagement rate is GA4's replacement for the old "bounce rate" metric, but it measures the opposite. An engaged session is one that lasts longer than 10 seconds, has at least two page views, or includes a conversion event. The engagement rate is the percentage of sessions that qualify as engaged.

A site with a 65% engagement rate means 65 out of every 100 sessions produced meaningful interaction. This is a more actionable metric than bounce rate because it tells you what users are doing, not just when they are leaving.

Conversions

In GA4, a conversion is any event you designate as important. By default, GA4 automatically marks certain events as key events (purchases on ecommerce sites, form submissions if using Google Tag Manager's form tracking). You can promote any event to a key event in Admin under "Key events."

Setting Up Conversions

Defining Events as Key Events

To track a form submission as a conversion, first confirm the event is being collected. Go to Reports, then Realtime, submit a test form, and check whether the event appears.

Once confirmed, go to Admin, select the property, click "Key events" under Data display, and click "New key event." Enter the exact event name as it appears in your data.

Using Audiences with Conversions

Create audience segments for users who completed a key event and compare their behavior to users who did not. This analysis often reveals which content, channels, or entry pages lead most reliably to conversions, helping you invest more in what works.

Reading GA4 Reports

Acquisition Reports

The User Acquisition report shows where new users come from: organic search, direct traffic, paid search, social media, or referral links. Use this report to understand which channels are growing your audience.

Engagement Reports

The Pages and screens report shows which content gets the most views and the longest average engagement time. Sort by engagement time to identify your highest-quality pages. Use these insights to update underperforming pages so they match the structure and depth of your top performers.

Setting Up a Custom Dashboard

GA4's default reports cover most needs, but custom explorations let you build reports that answer specific business questions. The Funnel exploration shows exactly where users drop off in a multi-step process. The Path exploration shows the most common sequences of pages users visit. Both are accessible under Explore in the left navigation.