Google Analytics 4: The Complete Beginner's Guide

Why Google Analytics 4 is essential in 2026

Google Analytics 4 (GA4) has established itself as the reference web analytics tool since the definitive disappearance of Universal Analytics in July 2024. In 2026, GA4 is not only the industry standard but also a considerably more powerful and mature tool than at launch. Yet a recent study reveals that 65% of businesses don't use even half of GA4's features, depriving themselves of strategic insights for their growth.

Unlike Universal Analytics, which relied on a session and pageview model, GA4 adopts a model entirely based on events. Every user interaction — a click, scroll, video view, purchase, search — is recorded as an event. This approach offers unprecedented flexibility and analytical granularity, but it requires a true mindset shift for marketers used to the old interface.

This guide is designed to walk you step by step through mastering GA4, whether you start from zero or want to deepen your knowledge. From initial installation to advanced exploitation via BigQuery, every section is built to be immediately actionable.

GA4 offers a complete view of the user journey thanks to its event-based model.

Without reliable data, every marketing decision is a gamble. Google Analytics 4 turns intuitions into certainties and assumptions into informed strategies. Investing in mastering it is the best marketing investment you can make.

Migrating from Universal Analytics to GA4: what you need to know

If you used Universal Analytics for years, the transition to GA4 can feel destabilizing. Interfaces, metrics and even the philosophy of measurement are fundamentally different. Understanding these differences is the first step to fully exploiting GA4.

The fundamental differences between UA and GA4

• Data model: UA was based on sessions (a group of interactions during a given period). GA4 is based on events (every interaction is an independent event). This event-based approach offers a more granular and flexible view of user behavior.
• Key metrics: UA's bounce rate has been replaced by GA4's engagement rate, a more relevant metric measuring sessions with significant engagement (over 10 seconds, at least 2 pageviews or at least one conversion).
• Cross-platform tracking: GA4 unifies web and mobile app tracking in a single property, allowing you to track a user across the full journey between browser and app.
• Data retention: GA4 retains granular data for 2 or 14 months maximum (depending on your configuration). Aggregated reports remain available indefinitely, but exploration data is time-limited.
• Artificial intelligence: GA4 integrates machine learning models for automatic insights, conversion predictions, anomaly alerts and predictive audiences.

Historical data after migration

A crucial point to understand: your Universal Analytics data is not importable into GA4. The two platforms collect data independently. That's why it was essential to configure GA4 in parallel with UA from 2023. If you don't have historical GA4 data, you'll need to rebuild your benchmarks and performance references from data collected since your installation.

Install and configure GA4 correctly

Correct GA4 installation is the foundation of any reliable analysis. A faulty configuration produces erroneous data that will inevitably lead to bad marketing decisions. Invest the time needed to do things right from the start.

Create a GA4 property

1. Access Google Analytics (analytics.google.com) and sign in with your Google account.
2. Create an account if you don't have one, or select an existing account in the admin panel.
3. Create a new GA4 property: click "Create a property", enter your site name, select your time zone and currency. The time zone choice matters because it determines the boundaries of your days in reports.
4. Configure data streams: choose "Web" as platform and enter your site URL. GA4 generates a measurement ID in the format G-XXXXXXXXXX.
5. Activate enhanced measurement: this feature automatically collects key events without additional configuration (scrolls, outbound clicks, internal searches, video interactions, file downloads).

Install the tracking code

You have two main methods to install GA4 on your site:

• Via Google Tag Manager (recommended): the most flexible and scalable method. Create a GTM container, add the GTM snippet on every page, then configure a GA4 tag in the GTM interface. This approach lets you add and modify events without touching your site's source code.
• Direct installation (gtag.js): copy the JavaScript snippet provided by GA4 and paste it into the <head> of every page on your site. Simpler to set up but less flexible for future evolution and advanced event management.

Whichever method you choose, verify immediately that data is flowing in correctly by checking GA4's real-time report while browsing your site in another tab.

Correct GA4 installation is the essential foundation of any effective data-driven strategy.

Understand and master events

Events are the heart of GA4. Absolutely everything that happens on your site is measured as an event. Understanding the different event categories and knowing how to create custom events is the most important skill to acquire to exploit GA4.

The four GA4 event types

• Automatically collected events: GA4 records them with no configuration on your part. They include first_visit, session_start, page_view and user_engagement. These events form the base of your data.
• Enhanced measurement events: automatically collected when enhanced measurement is enabled in your data stream settings. They cover scroll (90% scroll), outbound clicks, internal search (view_search_results), video interactions (video_start, video_progress, video_complete) and file downloads (file_download).
• Recommended events: Google offers a list of standardized events for different industries. For e-commerce: add_to_cart, begin_checkout, purchase. For lead generation: generate_lead, sign_up. Using these standardized names gives you access to predefined reports and advanced features.
• Custom events: for anything that doesn't fit in the previous categories, you can create your own events with the parameters of your choice. For example: form_submit_contact, cta_click_pricing, chat_opened.

Create custom events with GTM

Google Tag Manager is the tool of choice to create custom events without technical intervention. The process breaks down into three steps: define a trigger that identifies the interaction to measure, create a GA4 Event tag that sends the event, and publish the container. For example, to track clicks on a "Request a quote" button, create a "Click" trigger filtered on the button element, associate it with a GA4 Event tag named request_quote and add parameters like page_location and button_text to enrich your analyses.

Configure strategic conversions

In GA4, a conversion is simply an event you've marked as important for your business. Conversion configuration is the pivot of your analysis because it determines which user behaviors GA4 will optimize and highlight in its reports.

Essential conversions by activity

1. Showcase site / lead generation: contact form submission, click on phone number, online chat opening, white paper download, newsletter subscription.
2. E-commerce: purchase, add to cart (add_to_cart), beginning of checkout (begin_checkout), account signup (sign_up).
3. SaaS / app: free trial signup, account activation, upgrade to paid plan, use of a key feature.
4. Content / media: newsletter signup, article share, full video view, deep engagement (over 5 minutes on site).

To mark an event as a conversion, go to Admin > Events, then activate the "Mark as conversion" toggle next to the desired event. You can also create custom conversions in Admin > Conversions.

Navigate GA4 reports

GA4's interface is organized around several report categories that each answer strategic questions about your audience and its behaviors. Mastering this navigation is essential to quickly extract the insights you need.

Standard reports

• Real-time reports: visualize current activity on your site (active users, pages viewed, events triggered, conversions in progress). Essential to verify your tracking works after deployment or configuration change.
• Acquisition reports: understand where your visitors come from. The Overview report shows the main channels (organic search, paid advertising, social media, direct, referral). The Traffic acquisition report details performance by source, medium and campaign.
• Engagement reports: analyze how users interact with your content. Pages and screens shows the most popular content. Events lists all recorded interactions. Conversions lists the performance of your goals.
• Monetization reports: for e-commerce sites, track revenue, best-selling products, average order value, purchase journey and most effective promotions.
• Retention reports: measure your audience's loyalty with return rate, visit frequency, customer lifetime value and cohort analyses.
• Demographic reports: discover who your visitors are in terms of age, gender, geographic location, language and interests.

The Explorations tool: advanced analysis

The Explorations tool is GA4's most powerful feature for analyses that go beyond standard report capabilities. This is where analysts spend most of their time extracting actionable, non-obvious insights.

The available exploration types

• Free-form exploration: create custom pivot tables by combining the dimensions and metrics of your choice. The most flexible format, ideal for ad hoc analyses and exploratory questions.
• Funnel exploration: visualize the steps of the user journey and identify friction points where users abandon. Essential to optimize conversion funnels.
• Path exploration: discover the real paths your users take on your site, page after page. This tree visualization reveals unexpected behaviors and optimization opportunities.
• Segment overlap: visually compare overlaps between different audience segments to identify high-potential subgroups.
• Cohort analysis: follow the behavior of user groups over time to understand retention, loyalty and customer lifetime value.
• User lifetime: analyze cumulative metrics across the entire lifecycle of a user, from first visit to most recent conversions.

GA4 explorations let you discover insights impossible to obtain with standard reports.

Create an effective funnel exploration

Funnel analysis is probably the most valuable exploration for online businesses. To create one: select "Funnel exploration" in the templates, define the steps of your journey (for example: page_view of product page > add_to_cart > begin_checkout > purchase), then analyze the conversion rate between each step. Use segments to compare performance by traffic source, by device or by user type.

Audiences and segments: target with precision

Audiences in GA4 are user groups defined by behavioral, demographic or technological criteria. They serve two major objectives: analysis (segmenting your reports) and activation (exporting to Google Ads for remarketing).

Create custom audiences

GA4 lets you create audiences with remarkable granularity. Here are examples of strategic audiences to configure:

• High-intent visitors: users who viewed more than 3 product pages and spent over 5 minutes on the site without converting. Target them in remarketing with a special offer.
• Cart abandoners: users who triggered add_to_cart but not purchase in the last 7 days. The most profitable segment in e-commerce remarketing.
• Loyal customers: users who made at least 2 purchases in the last 90 days. Offer them a loyalty program or complementary products.
• Engaged readers: users who read at least 3 blog articles with average engagement time over 2 minutes. Offer them a lead magnet or newsletter signup.

Predictive audiences

GA4 uses machine learning to create predictive audiences that anticipate the future behavior of your users. Predictive audiences identify users likely to convert or churn within the next 7 days, letting you act proactively rather than reactively. For these audiences to be available, your property must have sufficient data volume (at least 1,000 users with the target behavior and 1,000 without).

BigQuery: exploit your raw GA4 data

GA4's native integration with BigQuery is one of the most significant advances over Universal Analytics. BigQuery is Google's cloud data warehouse that lets you store and query massive volumes of data with SQL. In 2026, BigQuery export is free for all GA4 properties, even non-paying accounts.

Why use BigQuery with GA4

• Unlimited retention: unlike GA4 reports that limit granular data to 2 or 14 months, BigQuery keeps your data as long as you want.
• Advanced analyses: SQL lets you run queries impossible in the GA4 interface, like complex path analyses, custom LTV (lifetime value) calculations or correlations between behaviors and conversions.
• Data joins: combine your GA4 data with data from your CRM, product database or other sources for a 360-degree view of your customers.
• Advanced visualization: connect BigQuery to Looker Studio, Tableau or Power BI to create custom dashboards that meet your team's exact needs.
• Machine learning: use BigQuery ML to create your own predictive models based on your GA4 data (conversion prediction, automatic segmentation, anomaly detection).

Configure BigQuery export

Activating BigQuery export takes a few steps: go to Admin > BigQuery Links in GA4, select your Google Cloud project (create one if needed), choose between daily export (data aggregated once per day) and continuous export (near real-time data, recommended), then validate. Data starts flowing into BigQuery within 24 hours. Note that BigQuery storage is free up to 10 GB and queries are free up to 1 TB per month, which is more than enough for most sites.

BigQuery is the qualitative leap that turns GA4 from a reporting tool into a true business intelligence platform. Don't let SQL intimidate you: basic queries are accessible to any curious marketer, and the results largely justify the learning investment.

Attribution models in GA4

Attribution is the process that determines which marketing channel receives credit for a conversion. It's a fundamental question for any marketer: if a user discovers your brand via a Facebook ad, returns via a Google search and converts after clicking an email, which channel gets credit for the sale?

The data-driven attribution model

GA4 uses by default a data-driven attribution model that relies on machine learning to analyze the actual conversion paths of your users and attribute weight to each touchpoint based on its real contribution to the conversion. This model is significantly more accurate than simplistic approaches like last click or first click.

The other available models

• Last click: 100% of credit to the last channel before conversion. Simple but misleading because it ignores all channels that contributed to discovery and consideration.
• First click: 100% of credit to the first channel that introduced the user. Useful to evaluate pure acquisition channels.
• Linear: credit is split evenly between all touchpoints. A good starting point if you lack data for the data-driven model.
• Time decay: touchpoints closest to the conversion get more credit. Suitable for short purchase cycles.
• Position-based: 40% to the first contact, 40% to the last, 20% spread between intermediate points. A good compromise between first click and last click.

The "Model comparison" report in GA4 lets you visualize the impact of each model on your conversion attribution, channel by channel. It's a revealing exercise that often shows that some channels are systematically undervalued by last click (like organic content or social media that play a discovery role early in the journey).

Conclusion: leverage GA4 to make better decisions

Google Analytics 4 is much more than a visit-counting tool: it's a decision-support system that, properly configured and exploited, can transform the performance of your digital marketing. The learning curve may seem intimidating, but the benefits in terms of audience understanding, investment optimization and business growth are considerable.

Businesses that master GA4 don't just measure their performance: they understand why some campaigns work and others don't, identify the most profitable audience segments, optimize each step of the customer journey and anticipate future behaviors thanks to predictive models. This data-driven intelligence is what makes the difference between random growth and steered growth.

At Pirabel Labs, we support our clients in configuring, customizing and exploiting GA4 and BigQuery. From initial installation to creating advanced Looker Studio dashboards, our analytics team brings its expertise to your service so that every marketing decision is guided by reliable and actionable data.

Contact Pirabel Labs for a free audit of your analytics configuration and discover the strategic insights you may be missing.