What is Google Analytics 4 Migration?

If you're noticing a significant lack of new data in your old, familiar Google Analytics reports, it's not a bug. Universal Analytics (UA), the version of Google Analytics that businesses used for years, officially stopped processing new website hits on July 1, 2023. This article breaks down what the GA4 migration was, why it happened, and what you need to do now that Google Analytics 4 is the new standard.

What Was Universal Analytics (and Why Did It Go Away)?

For over a decade, Universal Analytics was the go-to tool for understanding website performance. It was built for a simpler, desktop-first internet and was brilliant at measuring things like sessions, pageviews, and bounce rate. You could see how many people visited your site, which pages they looked at, and how long they stayed.

The core of Universal Analytics was the "session." A session was a group of interactions a user took within a given time frame. Think of it like a single visit to a store. Everything was measured within the context of that visit.

But the way we use the internet changed dramatically, and UA struggled to keep up. Its main challenges included:

A Cookie-Dependent World: UA relied heavily on browser cookies to anonymously track users. As privacy regulations like GDPR and CCPA tightened and browsers like Safari and Firefox began blocking third-party cookies, this model became less reliable.
The Cross-Device Problem: The average person now uses multiple devices - a phone on the train, a laptop at work, a tablet at home. UA saw the same person on three different devices as three different users, making it incredibly difficult to see a single, unified customer journey.
Website vs. App Divide: If you had a website and a mobile app, you needed two separate Google Analytics properties with completely different measurement models. You couldn't easily see how users moved between them.

In short, the session-based model of UA wasn't flexible enough for the modern, multi-device, privacy-conscious digital world. A fundamental change was needed.

What is Google Analytics 4?

Google Analytics 4 is Google's next-generation analytics platform, built from the ground up to solve the problems Universal Analytics couldn't. Instead of organizing everything around sessions, GA4 uses a totally different approach: the event-based model.

In GA4, every single interaction a user takes is captured as an "event." Viewing a page is a page_view event. Scrolling down a page is a scroll event. Clicking a link is a click event. Submitting a form or making a purchase are also events. This might sound like a small change, but it’s a massive philosophical shift that unlocks a far more flexible and comprehensive way of measuring what matters.

Key Differences & Benefits of GA4

1. Event-Based Data Model

Because anything can be an event, you're no longer limited to basic metrics like pageviews. You can track highly specific user interactions out-of-the-box (like video plays, file downloads, and outbound clicks) without complex custom code. This lets you measure what's actually important to your business, not just what UA decided was important.

2. Cross-Device & Cross-Platform Tracking

This is GA4's superpower. It's designed to unify user data from both your website and mobile apps into a single reporting view. Using a combination of identifiers, including a user-ID you can set yourself, GA4 can stitch together a user’s journey as they switch from browsing your app on their phone to visiting your website on their laptop. Finally, you can see the whole picture.

3. Privacy-Centric by Design

GA4 was built for a world without cookies. It offers more granular privacy controls, IP anonymization is enabled by default, and it uses machine learning and statistical modeling to fill in the gaps for users who don't consent to tracking. This allows you to get valuable insights into user behavior while respecting their privacy.

4. AI-Powered Insights

With its new data model, GA4 introduces predictive metrics. The AI can analyze your data to calculate the probability of a user purchasing or churning within the next 7 days, allowing you to create predictive audiences for your advertising campaigns. It also features powerful anomaly detection that can automatically alert you to significant changes or trends in your data.

Understanding the "GA4 Migration" Process

One of the most confusing parts of the transition was the term "migration." This word suggests you could just move your old UA data and settings over to GA4. Unfortunately, that's not how it works.

You cannot transfer historical data from Universal Analytics to Google Analytics 4.

The measurement models are completely different - it's like trying to mix oil and water. UA measured sessions and pageviews, GA4 measures events and parameters. A "migration" was really a process of rebuilding your analytics setup from scratch in a new GA4 property.

Here’s a breakdown of the key steps that were required (and that you’ll still need to follow if you're just getting started).

Step 1: Create Your GA4 Property

Every Google Analytics account now has a GA4 property. If you had a UA property, Google likely created a basic, connected GA4 property for you automatically. You typically did this using the GA4 Setup Assistant in the Admin section of your Universal Analytics property. This tool created the new GA4 property and copied over some basic settings, but it didn't configure your tracking.

Step 2: Install the GA4 Tracking Tag

Just like UA had its tracking ID (e.g., UA-1234567-1), GA4 has a Measurement ID (e.g., G-ABCDEFG789). You need to add this new tag snippet to your website to start collecting data.

For manual installations: You'd replace the old analytics.js or gtag.js UA script in your website's code with the new GA4 gtag.js script.
For Google Tag Manager (GTM) users (Recommended): The best practice is to set up a new GA4 Configuration Tag in your GTM container and have it fire on all pages. This keeps your tracking code organized and makes it much easier to manage events later on.

Step 3: Recreate Goals as Conversions

This step is where most of the hands-on work happens. In Universal Analytics, "Goals" were used to track valuable actions, like filling out a form or visiting a thank-you page.

In GA4, the concept is simpler yet more powerful: any event can be marked as a conversion. You first set up the tracking for an event (like a successful form submission), and then you simply toggle a switch in the GA4 interface to tell it that this specific event should be counted as a conversion.

For example:

UA Goal: Destination goal fires on /thank-you page.
GA4 Conversion: Create an event called generate_lead which triggers whenever a user views the /thank-you page. Then, mark the generate_lead event as a conversion.

Step 4: Connect Google Ads & Rebuild Audiences

If you're running ads, you need to link your Google Ads account to your new GA4 property. This allows conversion data to flow into your ad campaigns and enables you to build remarketing audiences from GA4 events.

Your old Universal Analytics audiences won't transfer. You have to recreate them from scratch in GA4, using new criteria based on GA4 events, user properties, and predictive metrics.

Step 5: Back Up Your Universal Analytics Data (Crucial!)

Universal Analytics properties have stopped processing data, and Google will eventually remove access to the UA interface and delete all historical data entirely. Before that happens, it’s imperative to export your old data if you want to keep it for historical analysis. Your options are:

Manual Export: Go into your key UA reports and export them as a CSV, Excel file, or Google Sheet. This is tedious but works for saving top-level data.
Google Analytics Reporting API: More technical, but developers can use the API to programmatically pull large amounts of data into a database or data warehouse like BigQuery.
Third-Party Connectors: Tools and connectors for platforms like Google Sheets or Looker Studio (now Google Data Studio) can help automate the export process.

What if I Missed the July 1, 2023 Deadline?

Don't panic. You aren't alone. You didn't "break" anything, but you stopped collecting new performance data on that date. As of a few months post-deadline, your historical UA data is still likely accessible in a read-only state, but you have no time to waste.

Here are your two immediate priorities:

Set up your GA4 property correctly today. The sooner you get proper tracking in place, the sooner you start collecting new data. Every day you wait is a day of insight you lose, and it creates an even bigger gap in data when you try to do year-over-year comparisons down the line.
Export your historical UA data now. Do not put this off. Once Google deletes that data, it is gone forever. Prioritize saving your most important performance metrics so you have a baseline for future comparison.

Think of this as an opportunity. It's a clean slate to re-evaluate how you measure success. Instead of trying to replicate your old UA setup exactly, take time to think about which user actions truly drive your business forward and focus on tracking those interactions as events in GA4.

Final Thoughts

The switch from Universal Analytics to GA4 represented a fundamental rethinking of digital analytics. It was a move away from the rigid, session-based world to a flexible, user-centric, and more private event-based model. "Migration" was never about flipping a switch, it was about thoughtfully rebuilding how you measure your digital presence for the modern online landscape.

Manually gathering data for analysis and reporting can be incredibly time-consuming, especially when your performance data lives in different systems like Google Analytics, your various ad platforms, and your CRM. We built Graphed to unify all your marketing and sales data in one place, effortlessly. Instead of wrestling with spreadsheet exports or learning a complex new GA4 interface, you can connect your accounts in seconds and use simple natural language to ask questions like, "Show me a dashboard of my GA4 traffic and conversions alongside my Facebook Ads spend for last month," and get an interactive, real-time dashboard instantly.