Google Analytics 4 Complete Guide: Everything You Need to Know

Google Analytics 4 is the only game in town. Universal Analytics is gone, and GA4 is the standard web analytics platform for the foreseeable future.

But I understand why so many people find GA4 frustrating. The interface is different, the data model changed fundamentally, and features you relied on in Universal Analytics either moved or disappeared. After working with GA4 since its early days, I can tell you that once you understand its logic, it is genuinely more powerful than what came before.

This guide covers everything you need to know: from initial setup to advanced features, with a focus on practical use cases rather than theoretical concepts.

Google Analytics 4 main dashboard overview

GA4 Fundamentals: The Data Model

Before diving into setup, you need to understand the fundamental change in GA4's data model.

Universal Analytics was session-based. Everything revolved around sessions, pageviews, and hit types.

GA4 is event-based. Everything -- pageviews, clicks, scrolls, purchases, form submissions -- is an event. Sessions still exist, but they are derived from events rather than being the primary unit.

This matters because:

You have much more flexibility in tracking user interactions
Cross-platform tracking (web + app) uses the same data model
Custom events let you track virtually anything
Attribution is more nuanced and accurate

Key GA4 Concepts

Events: Every user interaction is an event. GA4 collects some automatically (page_view, session_start, first_visit), enhanced measurement events (scroll, click, file_download, video_engagement), and custom events you define.

Parameters: Events carry parameters (additional data). A purchase event might include parameters for value, currency, item names, and quantities.

Users: GA4 tracks users across sessions using a combination of User ID, Google Signals, device ID, and modeled data.

Sessions: Derived from events. A session starts with session_start and has a 30-minute inactivity timeout.

Key events (Conversions): Events you mark as important to your business. Previously called "conversions" in GA4, now referred to as "key events."

Setting Up GA4 Properly

Step 1: Create Your GA4 Property

Go to admin.google.com/analytics
Click "Create Property"
Enter your property name, reporting time zone, and currency
Select your industry category and business size
Choose your business objectives (this customizes default reports)

Step 2: Add a Data Stream

A data stream connects your website or app to your GA4 property.

For a website:

Click "Data Streams" in the admin section
Click "Add stream" and select "Web"
Enter your website URL and stream name
Copy your Measurement ID (G-XXXXXXXXXX)

Step 3: Install the Tracking Code

Option A: Google Tag Manager (Recommended)

Create a Google Tag Manager account and container
Add the GTM snippet to your website's <head> and <body>
In GTM, create a new GA4 Configuration tag
Enter your Measurement ID
Set the trigger to "All Pages"
Publish the container

Option B: Direct Installation Add the gtag.js snippet directly to your website's <head>:

<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXXXXXXX"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-XXXXXXXXXX');
</script>

Option C: CMS Plugins WordPress users can install Google Site Kit or a GA4 plugin. For other CMS options, see our WordPress plugins guide.

Step 4: Configure Enhanced Measurement

Enhanced Measurement automatically tracks common interactions. Go to your data stream settings and enable:

Page views (on by default)
Scrolls (90% scroll depth)
Outbound clicks
Site search
Video engagement (YouTube embeds)
File downloads
Form interactions

I recommend enabling all of these unless you have a specific reason not to.

Step 5: Set Up Key Events (Conversions)

Identify the actions that matter most to your business and mark them as key events:

For a blog:

Newsletter signup
Contact form submission
Affiliate link click
Content download

For e-commerce:

Purchase
Add to cart
Begin checkout
View item

For SaaS:

Sign up / account creation
Trial start
Feature usage milestones
Upgrade/purchase

Navigate to Admin > Key Events to mark existing events or create new ones.

Custom Event Tracking

The real power of GA4 comes from custom events tailored to your business. Here is how to set them up:

Using Google Tag Manager

Define your event. What user action do you want to track? (Button click, form submission, scroll to specific section, etc.)
Create a trigger in GTM. Configure when the event should fire based on the user action.
Create a GA4 Event tag. Map the trigger to a GA4 event with relevant parameters.
Test in preview mode. Always test before publishing.
Publish and verify in GA4 DebugView.

Recommended Custom Events

Event Name	Parameters	Use Case
newsletter_signup	source, form_location	Track email signups
affiliate_click	product_name, destination_url	Track affiliate clicks
content_engagement	article_title, scroll_depth, time_on_page	Measure content quality
cta_click	cta_text, cta_location, destination	Track CTA effectiveness
search_query	search_term, results_count	Understand user intent

Event Naming Conventions

GA4 has strict naming rules:

Event names are case-sensitive
Use snake_case (lowercase with underscores)
Maximum 40 characters
Cannot start with a number or "google_" or "firebase_"
Up to 500 distinct event names per property
Up to 25 parameters per event

Understanding GA4 Reports

Realtime Report

Shows activity happening on your site right now. Useful for:

Verifying tracking is working after setup
Monitoring campaign launches
Checking real-time traffic during events

Acquisition Reports

User acquisition: How new users first discover your site. Dimensions include first user source, medium, campaign.

Traffic acquisition: How all users (new and returning) arrive at your site per session.

Key metrics: Users, sessions, engagement rate, key events.

Engagement Reports

Events: All events being collected, with counts and user counts.

Pages and screens: Performance of individual pages (replaces the old "All Pages" report).

Landing pages: Which pages users arrive on first.

Key metrics: Engagement rate, engaged sessions per user, average engagement time.

Monetization Reports

If you have e-commerce tracking configured:

Revenue by product, category, and brand
Purchase funnel analysis
Promotion and coupon performance

Retention Reports

User retention over time: how many users return after their first visit, and how often.

Explorations: GA4's Most Powerful Feature

Explorations are where GA4 truly outshines Universal Analytics. They provide flexible, custom analysis capabilities that previously required BigQuery or third-party tools.

Exploration Types

Free-form exploration: The most versatile. Build custom tables, charts, and graphs with any combination of dimensions and metrics.

Funnel exploration: Visualize user journeys through defined steps. See where users drop off and how different segments behave.

Path exploration: Discover the paths users take through your site. Start from a page or event and see where they go next (or where they came from).

Segment overlap: Compare up to three user segments visually. Understand which audiences overlap and which are distinct.

User lifetime: Analyze users over their entire relationship with your site, not just individual sessions.

Cohort exploration: Group users by acquisition date and track their behavior over time.

Building Your First Exploration

Go to Explore in the left navigation
Click "Blank" to start from scratch
In the Variables panel, add the dimensions and metrics you need
Drag them into the Tab Settings panel to build your report
Apply segments and filters as needed
Save and share with your team

AI Insights in GA4

GA4's AI-powered insights surface anomalies, trends, and opportunities automatically. You will find them in the Insights section of the Home report.

What GA4 AI can tell you:

Traffic anomalies (sudden spikes or drops)
Conversion trend changes
Audience behavior shifts
Predicted revenue and churn (for eligible properties)
Custom insight alerts you configure

Setting up custom insights:

Go to Insights and click "Create"
Define the metric and conditions
Set the evaluation frequency
Choose notification preferences

Example custom insights:

Alert when daily organic traffic drops by more than 20%
Notify when conversion rate for a specific page changes significantly
Flag when a new traffic source exceeds 100 sessions

Understanding the ML systems behind these AI insights gives you a better sense of when to trust them and when to investigate further. Designing Machine Learning Systems covers the architectures that power these kinds of analytical AI features.

BigQuery Integration

For serious analytics, BigQuery integration unlocks the full power of GA4 data.

Why BigQuery Matters

Raw data access: See every individual event, not aggregated summaries
Custom analysis: Run SQL queries on your complete dataset
Data retention: GA4 standard retains data for 2-14 months. BigQuery stores it indefinitely
ML capabilities: Build predictive models on your analytics data
Cross-platform joining: Combine GA4 data with CRM, email, and other sources

Setting Up BigQuery Export

Create a Google Cloud project (or use an existing one)
In GA4 Admin, go to BigQuery Links
Click "Link" and select your Cloud project
Choose daily export (free for most sites) or streaming export (costs apply)
Select which events to export

Cost considerations: Daily export is free within BigQuery's free tier (10 GB storage, 1 TB queries/month). Streaming export costs approximately $0.05 per 200MB.

Essential BigQuery Queries

Here are starter queries I use regularly:

Top pages by engaged sessions:

SELECT
  (SELECT value.string_value FROM UNNEST(event_params) WHERE key = 'page_location') AS page,
  COUNT(DISTINCT CONCAT(user_pseudo_id, (SELECT value.int_value FROM UNNEST(event_params) WHERE key = 'ga_session_id'))) AS sessions
FROM `your-project.analytics_XXXXXXXX.events_*`
WHERE event_name = 'page_view'
  AND _TABLE_SUFFIX BETWEEN '20260201' AND '20260224'
GROUP BY page
ORDER BY sessions DESC
LIMIT 20

Conversion path analysis:

SELECT
  traffic_source.source,
  traffic_source.medium,
  COUNT(*) AS conversions
FROM `your-project.analytics_XXXXXXXX.events_*`
WHERE event_name = 'purchase'
  AND _TABLE_SUFFIX BETWEEN '20260201' AND '20260224'
GROUP BY 1, 2
ORDER BY conversions DESC

Common GA4 Mistakes and How to Fix Them

Mistake 1: Not Setting Data Retention

By default, GA4 retains user-level data for 2 months. Change this immediately.

Fix: Admin > Data Settings > Data Retention > Set to 14 months.

Mistake 2: Ignoring Filters

Without filters, your data includes internal traffic, development environments, and spam.

Fix: Admin > Data Streams > Configure Tag Settings > Define Internal Traffic. Then create a data filter to exclude it.

Mistake 3: Not Linking Google Services

GA4 works best when connected to your other Google tools.

Essential links:

Google Ads (for campaign data and audiences)
Google Search Console (for organic search data)
BigQuery (for raw data access)
Google Merchant Center (for e-commerce)

Mistake 4: Over-Relying on Default Reports

Default reports show a fraction of what GA4 can do. If you are only using default reports, you are missing the most valuable insights.

Fix: Learn Explorations. Start with the templates, then build custom analyses for your specific questions.

Mistake 5: Not Using UTM Parameters

GA4 relies on UTM parameters to properly attribute traffic from campaigns.

Fix: Use UTM parameters on every link you share in emails, social media, and paid campaigns. Format: ?utm_source=newsletter&utm_medium=email&utm_campaign=feb2026

GA4 for Content Marketers

If you are running a blog or content marketing strategy, here are the GA4 reports and explorations that matter most:

Content Performance Dashboard

Build an exploration that shows:

Top pages by engaged sessions
Average engagement time per page
Scroll depth distribution
Key event conversion rates by page
Traffic source breakdown per article

Author Performance Tracking

If multiple authors contribute, use custom dimensions to track author-level metrics:

Articles per author
Average engagement per author
Conversion rates by author
Traffic trends by author

Content Funnel

Track how content drives business outcomes:

Blog post view (page_view event)
Content engagement (scroll, time on page)
CTA click (custom event)
Newsletter signup or product view (key event)
Conversion (purchase, sign up, etc.)

Your GA4 Setup Checklist

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GA4 and Privacy in 2026

Privacy regulations continue to evolve. GA4 addresses this with:

Consent mode: Adjusts data collection based on user consent status
Data deletion requests: API for processing user data deletion
IP anonymization: Built-in by default
Data retention controls: Configurable at the property level
Google Signals: Optional feature that provides cross-device insights

Ensure your GA4 implementation complies with GDPR, CCPA, and any other relevant privacy regulations. Work with a legal advisor if you are unsure.

For a broader view of how analytics fits into your digital marketing strategy, our SEO trends guide covers how to connect GA4 data with search performance. If you want professionals who can translate your GA4 data into an actionable SEO growth plan, Scale by SEO uses analytics-driven insights to build search strategies that deliver measurable results.

Beyond the Basics

GA4 is a deep platform. Once you have the fundamentals in place, explore:

Audiences: Build custom audiences for remarketing and analysis
Predictive metrics: Purchase probability, churn probability, predicted revenue
User properties: Custom attributes for segmentation
Looker Studio: Connect GA4 to build custom dashboards
Data API: Pull GA4 data into custom applications and tools

The learning curve is real, but the insights GA4 provides are worth the investment. Start with the basics, build your comfort, and add complexity as your questions become more sophisticated.

Need help with your GA4 setup? Reach out on X (@wikiwayne) -- I regularly share GA4 tips and answer analytics questions.

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