January 20266 min read

Complete GA4 Guide

Master Google Analytics 4 from setup to advanced analysis in 2025.

Introduction

Google Analytics 4 (GA4) is Google's current analytics platform, having fully replaced Universal Analytics (UA) in July 2023. GA4 represents a fundamental shift in how digital analytics works—moving from session-based to event-based tracking.

In 2025, GA4 processes data for over 28 million websites worldwide, making it the dominant web analytics platform. Understanding GA4 is essential for measuring the performance of all your marketing channels.

Key Insight: GA4 isn't just an upgrade—it's a complete reimagining of analytics. Everything is an event, privacy is built-in, and machine learning powers insights automatically.

GA4 vs Universal Analytics

GA4 and Universal Analytics are fundamentally different:

| Aspect | Universal Analytics | GA4 | |--------|--------------------|----| | Data Model | Session-based | Event-based | | Tracking | Pageviews + Events | Everything is an event | | Cross-Platform | Web only | Web + App unified | | Privacy | Cookie-dependent | Privacy-first, cookieless support | | Machine Learning | Limited | Built-in predictions | | BigQuery | Paid (360 only) | Free for all | | Data Retention | Unlimited | 2-14 months |

Why Google Made the Switch

Privacy regulations (GDPR, CCPA) require less reliance on cookies
Cross-device journeys need unified web + app tracking
Machine learning can fill gaps when data is incomplete
Future-proofing for a cookieless world

The Biggest Mindset Shifts

code

UA Thinking → GA4 Thinking

"How many sessions?" → "How many engaged sessions?"
"Bounce rate" → "Engagement rate"
"Goals" → "Key events (conversions)"
"Views" → "Data streams"
"Segments" → "Audiences + Comparisons"

Account Structure

GA4 uses a hierarchical structure:

code

Google Analytics Account
├── Property (GA4)
│   ├── Data Stream (Web)
│   ├── Data Stream (iOS App)
│   └── Data Stream (Android App)
├── Property (GA4) - Another site
│   └── Data Stream (Web)
└── Account Settings
    ├── User Management
    └── Account Access

Key Components

Account Level:

Organization container
User permissions management
Can contain multiple properties
Billing and account settings

Property Level:

Single measurement entity
Contains all your data
Configuration settings
Audiences, conversions, custom definitions

Data Stream Level:

Individual data source
Web stream (website)
App streams (iOS, Android)
Measurement ID (G-XXXXXXX)

Account Limits

| Resource | Limit | |----------|-------| | Properties per account | 2,000 | | Data streams per property | 50 | | Custom dimensions | 50 event-scoped, 25 user-scoped | | Custom metrics | 50 | | Audiences | 100 | | Conversions | 30 |

The Event-Based Data Model

In GA4, everything is an event. This is the most important concept to understand.

Event Structure

code

// Every interaction is an event with parameters
{
  "event_name": "purchase",
  "parameters": {
    "transaction_id": "T12345",
    "value": 99.99,
    "currency": "USD",
    "items": [...]
  }
}

Event Categories

| Category | Description | Examples | |----------|-------------|----------| | Automatically Collected | Tracked without configuration | first_visit, session_start, page_view | | Enhanced Measurement | Toggle on/off in UI | scroll, outbound_click, file_download, video_start | | Recommended Events | Google-suggested names | purchase, sign_up, add_to_cart | | Custom Events | You define these | custom_button_click, pricing_view |

Key Automatically Collected Events

code

first_visit - First time user visits
session_start - New session begins
page_view - Page is loaded
user_engagement - User actively engaged

Enhanced Measurement Events

Enable in Admin → Data Streams → Enhanced Measurement:

| Event | Trigger | |-------|---------| | page_view | Page loads (history change) | | scroll | 90% page depth reached | | outbound_click | Click to external domain | | site_search | Site search performed | | video_start | Embedded video starts | | video_progress | 10%, 25%, 50%, 75% watched | | video_complete | Video finishes | | file_download | File download initiated | | form_start | Form interaction begins | | form_submit | Form submitted |

2025 Platform Updates

GA4 continues to evolve rapidly. Key 2025 updates include:

AI-Powered Insights

code

Generated Insights in Reports:
├── Automatic anomaly detection
├── Trend identification
├── Suggested causes for changes
└── Natural language explanations

New in 2025: AI-generated insights appear directly in reports, explaining traffic spikes, drops, and unusual patterns automatically.

Improved Conversion Accuracy

August 2025 updates addressed:

Under-reporting fixes
Duplicate session elimination
Reduced reporting latency
Better cross-device attribution

Enhanced Event Tracking

No-code event creation expanded:

Track button clicks without code
Form submission tracking
Video engagement
Custom interactions via UI

Key Events & Conversions Clarification

code

Terminology (2024+):

Key Events = Important actions in GA4 reports
Conversions = Key Events imported to Google Ads

An event can be both a Key Event AND a Conversion

Other 2025 Updates

Copy reports/explorations between properties
Campaign Data Import (renamed from Cost Data)
User-Provided Data enhancements for attribution
Measurement Protocol improvements for server-side

Getting Started Checklist

code

## Account Setup

□ Create Google Analytics account (analytics.google.com)
□ Create GA4 property
□ Add web data stream
□ Install tracking code (gtag.js or GTM)
□ Verify data in Realtime report
□ Set timezone and currency
□ Configure data retention (14 months recommended)

## Essential Configuration

□ Enable Enhanced Measurement events
□ Link Google Ads account
□ Link Google Search Console
□ Set up key events (conversions)
□ Configure cross-domain tracking (if needed)
□ Set up internal traffic filters
□ Create essential audiences

## Advanced Setup

□ Implement custom events for key actions
□ Configure custom dimensions/metrics
□ Set up BigQuery export
□ Enable Google Signals (for demographics)
□ Configure User-ID tracking (if applicable)
□ Set up Consent Mode (for GDPR/CCPA)

## Verification

□ Test all events in DebugView
□ Verify conversions are tracking
□ Check Realtime for data flow
□ Review data quality metrics

Pro Tip: Don't skip the verification step. Use DebugView (Admin → DebugView) to watch events fire in real-time during testing. This catches 90% of tracking issues before they affect your data.

January 20266 min read

Complete GA4 Guide

Master Google Analytics 4 from setup to advanced analysis in 2025.

Introduction

Key Insight: GA4 isn't just an upgrade—it's a complete reimagining of analytics. Everything is an event, privacy is built-in, and machine learning powers insights automatically.

GA4 vs Universal Analytics

GA4 and Universal Analytics are fundamentally different:

Why Google Made the Switch

Privacy regulations (GDPR, CCPA) require less reliance on cookies
Cross-device journeys need unified web + app tracking
Machine learning can fill gaps when data is incomplete
Future-proofing for a cookieless world

The Biggest Mindset Shifts

code

UA Thinking → GA4 Thinking

"How many sessions?" → "How many engaged sessions?"
"Bounce rate" → "Engagement rate"
"Goals" → "Key events (conversions)"
"Views" → "Data streams"
"Segments" → "Audiences + Comparisons"

Account Structure

GA4 uses a hierarchical structure:

code

Google Analytics Account
├── Property (GA4)
│   ├── Data Stream (Web)
│   ├── Data Stream (iOS App)
│   └── Data Stream (Android App)
├── Property (GA4) - Another site
│   └── Data Stream (Web)
└── Account Settings
    ├── User Management
    └── Account Access

Key Components

Account Level:

Organization container
User permissions management
Can contain multiple properties
Billing and account settings

Property Level:

Single measurement entity
Contains all your data
Configuration settings
Audiences, conversions, custom definitions

Data Stream Level:

Individual data source
Web stream (website)
App streams (iOS, Android)
Measurement ID (G-XXXXXXX)

Account Limits

The Event-Based Data Model

In GA4, everything is an event. This is the most important concept to understand.

Event Structure

code

// Every interaction is an event with parameters
{
  "event_name": "purchase",
  "parameters": {
    "transaction_id": "T12345",
    "value": 99.99,
    "currency": "USD",
    "items": [...]
  }
}

Event Categories

Key Automatically Collected Events

code

first_visit - First time user visits
session_start - New session begins
page_view - Page is loaded
user_engagement - User actively engaged

Enhanced Measurement Events

Enable in Admin → Data Streams → Enhanced Measurement:

2025 Platform Updates

GA4 continues to evolve rapidly. Key 2025 updates include:

AI-Powered Insights

code

Generated Insights in Reports:
├── Automatic anomaly detection
├── Trend identification
├── Suggested causes for changes
└── Natural language explanations

New in 2025: AI-generated insights appear directly in reports, explaining traffic spikes, drops, and unusual patterns automatically.

Improved Conversion Accuracy

August 2025 updates addressed:

Under-reporting fixes
Duplicate session elimination
Reduced reporting latency
Better cross-device attribution

Enhanced Event Tracking

No-code event creation expanded:

Track button clicks without code
Form submission tracking
Video engagement
Custom interactions via UI

Key Events & Conversions Clarification

code

Terminology (2024+):

Key Events = Important actions in GA4 reports
Conversions = Key Events imported to Google Ads

An event can be both a Key Event AND a Conversion

Other 2025 Updates

Copy reports/explorations between properties
Campaign Data Import (renamed from Cost Data)
User-Provided Data enhancements for attribution
Measurement Protocol improvements for server-side

Getting Started Checklist

code

## Account Setup

□ Create Google Analytics account (analytics.google.com)
□ Create GA4 property
□ Add web data stream
□ Install tracking code (gtag.js or GTM)
□ Verify data in Realtime report
□ Set timezone and currency
□ Configure data retention (14 months recommended)

## Essential Configuration

□ Enable Enhanced Measurement events
□ Link Google Ads account
□ Link Google Search Console
□ Set up key events (conversions)
□ Configure cross-domain tracking (if needed)
□ Set up internal traffic filters
□ Create essential audiences

## Advanced Setup

□ Implement custom events for key actions
□ Configure custom dimensions/metrics
□ Set up BigQuery export
□ Enable Google Signals (for demographics)
□ Configure User-ID tracking (if applicable)
□ Set up Consent Mode (for GDPR/CCPA)

## Verification

□ Test all events in DebugView
□ Verify conversions are tracking
□ Check Realtime for data flow
□ Review data quality metrics

Pro Tip: Don't skip the verification step. Use DebugView (Admin → DebugView) to watch events fire in real-time during testing. This catches 90% of tracking issues before they affect your data.