What Is Google Analytics 4 and How Do You Read It?

Google Analytics 4 (GA4) is Google's current web and app measurement platform: it records every interaction as an event (page_view, click, purchase) instead of just counting pageviews. To read it, start in the Reports module: the Acquisition, Engagement, Monetization, and Retention reports summarize where traffic comes from, how engaged users are, and how much revenue the site generates.

By Matias Valdivieso, Director, Vanta Designs. Updated: July 2026.

Key takeaways

• GA4 replaced Universal Analytics (UA); UA stopped processing new data on July 1, 2023, and most accounts lost access to the interface and historical data the week of July 1, 2024 (Google Analytics Help, 2024).
• Everything in GA4 is an "event," grouped into automatically collected, enhanced measurement, recommended, and custom events (Google Analytics Help, 2026).
• Since March 21, 2024, most GA4 conversions are called "key events" (Google Analytics Help, 2024).
• GA4 lets you choose 2 or 14 months of retention for event-level and user-level data on the standard tier; this setting affects explorations and funnel reports, not standard aggregated reports (Google Analytics Help, 2026).
• 84.1% of connected households in Chile now have fiber-optic internet, up 18.9% over the previous 12 months (Subtel, April 2026), which is why most of a Chilean SMB's customers are already measurable online.

What Is Google Analytics 4?

Google Analytics 4 is the web and app measurement platform Google introduced on October 14, 2020 as "the next generation of Analytics" (Google Analytics Help, 2020). Unlike its predecessor, GA4 was built from the ground up on an event-based model and designed to measure a website and a mobile app inside the same property. For a Chilean SMB, that means a customer's behavior on the site, and on the app if one exists, can be analyzed in one place instead of two separate tools.

How Is GA4 Different From Universal Analytics?

GA4 changed the underlying data model from sessions and pageviews to events, and it changed how data is processed and retained. Universal Analytics (UA), the prior version, stopped processing new data on July 1, 2023, and most accounts lost access to the interface and historical data the week of July 1, 2024 (Google Analytics Help, 2024). Anyone still checking UA reports today is looking at a frozen snapshot, not live data.

What Is an "Event" in GA4, and Why Does Everything Depend on It?

An event is every individual interaction GA4 records, such as page_view or session_start (Google Analytics Help, 2026). Google groups events into four types: automatically collected, enhanced measurement, recommended, and custom (Google Analytics Help, 2026). Automatically collected and enhanced measurement events, like page_view and session_start, are captured without extra code in most implementations that use gtag.js or Google Tag Manager. This matters because every GA4 report, from Acquisition to Monetization, is ultimately just counting and grouping events.

What Are "Key Events" (Conversions) in GA4?

A key event is an event a business marks as particularly important, such as a purchase or a submitted contact form. On March 21, 2024, Google renamed most GA4 conversions to "key events," reserving the word "conversion" mainly for traffic coming from Google Ads (Google Analytics Help, 2024). Existing conversions converted automatically, with no need to reconfigure tracking. For an online store running on Shopify or WordPress with WooCommerce, the typical key event is purchase; for a services business generating leads through HubSpot or Salesforce, it is usually a form submission or generate_lead.

Which Reports Should a Small Business Check First?

GA4 organizes its main reports into the Life cycle collection, which follows the customer journey through four stages: Acquisition (where traffic comes from), Engagement (which events and pages visitors use), Monetization (how much revenue products, ads, or subscriptions generate), and Retention (how often users come back) (Google Analytics Help, 2026). A simple weekly check is opening Acquisition to confirm which channel drives the most traffic, Engagement to see which pages hold attention, and Monetization if the site sells online; it is the same reading cycle a campaign and analytics management practice uses to decide where to invest.

How Do You Read the Reports Snapshot?

The Reports snapshot is the first screen inside the Reports module and summarizes the property's overall state using one of three templates: user behavior, sales and revenue, or marketing performance (Google Analytics Help, 2026). Each card on that screen is a summary of a detailed report; clicking a card opens the full report behind it. For a first read, focus on active users, events per session, and, if relevant, total revenue, then compare those figures against the prior week or month using the date picker.

What Do "Session," "Engaged Session," and "Engagement Rate" Mean?

A session groups the events a user generates within a defined time window, and the session_start event marks its beginning and carries the attribution data (channel, campaign, referrer) for that visit (Google Analytics Help, 2026). GA4 defines an engaged session as one that lasts longer than 10 seconds, includes a key event, or has at least two pageviews or screenviews, and engagement rate is the share of sessions that meet that condition (Google Analytics Help, 2026). A low engagement rate on a specific page usually points to a content or load-speed problem rather than a traffic problem.

How Long Does GA4 Keep Your Data, and Why Does It Matter?

GA4 lets a property admin set event-level and user-level retention to either 2 or 14 months on the standard tier (Google Analytics Help, 2026); that setting affects explorations and funnel reports only, not standard aggregated reports. The Retention report, separately, tracks users for their first 42 days to show what share return each day after their first visit (Google Analytics Help, 2026). When that curve drops quickly, the issue usually sits in the post-purchase experience, not in acquisition. The practical takeaway for an SMB is to export data or review comparisons periodically before those windows close.

Frequently Asked Questions

Is GA4 free?
Yes. The standard GA4 property is free; a paid tier, Google Analytics 360, exists for high-volume accounts that need higher data limits and extended retention (Google Analytics Help, 2026).

Do I need Google Tag Manager to use GA4?
No. GA4 can be installed directly with a gtag.js tag or through Google Tag Manager; Tag Manager usually makes it easier to add custom events without editing site code.

Does GA4 work for an online store?
Yes. GA4's ecommerce events, such as view_item, add_to_cart, and purchase, are built for exactly that case and are compatible with platforms like Shopify.

Can I export GA4 data to another tool?
Yes. GA4 includes free export to BigQuery, and its data can also connect to visualization tools like Looker Studio to build custom reports.

Sources: Google Analytics Help, "Introducing the next generation of Analytics, Google Analytics" (October 2020); Google Analytics Help, "Universal Analytics will be going away" (2024); Google Analytics Help, "About events" (2026); Google Analytics Help, "Automatically collected events" (2026); Google Analytics Help, "Conversions vs. key events" (March 2024); Google Analytics Help, "Life cycle collection" (2026); Google Analytics Help, "Reports snapshot" (2026); Google Analytics Help, "Engagement rate and bounce rate" (2026); Google Analytics Help, "Retention overview report" (2026); Google Analytics Help, "Data retention" (2026); Subtel, connectivity report (April 2026).