Complete GA4 Setup Guide for 2025

Introduction

Google Analytics 4 (GA4) is fundamentally different from Universal Analytics. If you're used to the old GA, you'll need to think differently about how you track and measure website performance.

This guide walks you through proper GA4 setup from scratch.

Why GA4 Matters in 2025

Universal Analytics stopped collecting data in July 2023. GA4 is now the only option, and it offers:

Event-based tracking instead of session-based
Better privacy controls to comply with regulations
Machine learning insights for predictive analytics
Cross-platform tracking (web + app in one property)

Prerequisites

Before starting, make sure you have:

Google account with appropriate permissions
Website with ability to add code snippets
Google Tag Manager (optional but recommended)

Step 1: Create GA4 Property

Go to analytics.google.com
Click Admin (bottom left)
Click "Create Property"
Enter property name (usually your website name)
Select timezone and currency
Click "Next"

Step 2: Set Up Data Stream

Choose platform: Web, iOS, or Android
Enter website URL
Name your stream
Enable "Enhanced measurement" (recommended)
Click "Create stream"

You'll receive a Measurement ID (format: G-XXXXXXXXXX)

Step 3: Install Tracking Code

Option A: Direct Installation

Add this code to the <head> section of every page:

<!-- Google tag (gtag.js) -->
<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 B: Google Tag Manager (Recommended)

Create GTM container
Add GTM code to your site
Create new tag in GTM: GA4 Configuration
Add your Measurement ID
Set trigger to "All Pages"
Publish container

Step 4: Configure Enhanced Measurement

Enhanced measurement automatically tracks:

Page views - Standard page tracking
Scrolls - 90% page scroll depth
Outbound clicks - Links to external sites
Site search - Internal search queries
Video engagement - YouTube video interactions
File downloads - PDF, DOC, ZIP, etc.

Enable/disable specific events in: Admin > Data Streams > [Your Stream] > Enhanced measurement

Step 5: Set Up Conversions

Go to Admin > Events
Click "Create event" for custom events
Or mark existing events as conversions
Common conversions:
- Form submissions
- Product purchases
- Newsletter signups
- CTA button clicks

Step 6: Link to Google Search Console

Go to Admin > Property Settings
Click "Search Console Links"
Click "Link"
Select GSC property
Choose data stream
Submit and confirm

This enables search query data in GA4 reports.

Step 7: Create Custom Reports

GA4's default reports don't show everything. Create custom explorations:

User acquisition - How users find your site
Engagement - Time, scrolls, and interactions
Conversions - Goal completions and value
Retention - Returning visitor behavior

Step 8: Test Your Setup

Visit your website
Check GA4 Real-time report
Verify events fire correctly
Test conversions
Use GA Debugger extension for troubleshooting

Common Setup Mistakes

Not enabling enhanced measurement - Missing valuable data
Skipping conversion tracking - Can't measure success
Ignoring data filters - Internal traffic skews data
Not linking GSC - Losing search performance insights
No custom events - Default events aren't enough

Next Steps

After basic setup:

Create custom audiences for remarketing
Set up Google Ads linking
Configure BigQuery export (for advanced users)
Build custom dashboards in Looker Studio

Conclusion

GA4 has a learning curve, but proper setup is crucial. Take time to configure it correctly now, and you'll have clean, actionable data for years to come.