Universal Analytics to GA4 Migration Guide for Beginners

Quick answer: Universal Analytics (UA) no longer collects or shows data, so migrating to Google Analytics 4 (GA4) today means setting up GA4 properly, recreating the tracking you rely on and, unless you exported your history, accepting that your old UA data is gone. This guide explains what changed, how UA and GA4 differ and gives you a step-by-step checklist to get GA4 tracking accurately.

What Happened to Universal Analytics?

Google retired Universal Analytics in stages. Standard UA properties stopped processing new data on 1 July 2023, and UA 360 properties followed on 1 July 2024. Google has since ended access to UA reports and data, so anyone who wanted their history needed to export it. If you have an old export, from BigQuery, the API or saved reports, keep it somewhere safe, because GA4 cannot import UA data.

GA4 itself is not new. It launched as “App + Web” in beta in 2019 and was renamed Google Analytics 4 in 2020. It was built for a world of apps, multiple devices and stricter privacy rules, which is why it works so differently from UA.

Universal Analytics vs GA4: What Changed?

How to Set Up GA4: A Step-by-Step Migration Checklist

1. Create a GA4 property and a web data stream. In Admin, create the property and add your website as a stream.
2. Install the tag. Add the Google tag directly or through Google Tag Manager, then confirm hits in Realtime and DebugView.
3. Review enhanced measurement. GA4 can track page views, scrolls, outbound clicks, site search, video engagement and file downloads automatically. Switch on what you need.
4. List what you tracked in UA. Write down goals, events, ecommerce, custom dimensions, audiences, filters and linked products.
5. Recreate your key tracking. Build the events you need, mark the important ones as key events, and add ecommerce events if you sell online.
6. Link your other tools. Connect Google Ads, Search Console and, if useful, BigQuery.
7. Set data retention to 14 months. This is in Admin under data settings and is not on by default.
8. Filter internal and unwanted traffic. Define internal traffic, exclude it and list unwanted referrals.
9. Handle consent. If you serve users in regions that require consent, make sure your cookie banner and consent settings work with your tags.
10. Validate against real outcomes. Check GA4 against orders, form submissions or CRM leads rather than expecting it to match old UA numbers.

What Does Not Carry Over From UA?

• Historical UA data, unless you exported it.
• Views and view-level filters.
• Goals in their old form, which you rebuild as events and key events.
• The exact definitions of sessions, users and bounce rate, so numbers will differ.
• Old custom reports, which need to be rebuilt as GA4 reports or explorations.

Common Mistakes When Moving to GA4

• Expecting GA4 numbers to match UA. They use different models and definitions.
• Leaving data retention at 2 months and losing detail in explorations.
• Forgetting to mark important events as key events, so conversions never appear.
• Tagging twice, through both the site code and Tag Manager, which inflates events.
• Skipping internal traffic filters, so team visits skew the data.
• Ignoring consent rules, which can leave gaps in your data.

When to Get Help

A clean GA4 setup is the foundation for every marketing decision that follows. If your numbers still look wrong, our guide to what analytics cannot tell you about mobile conversions explains why.

If you would rather have a specialist build and check your tracking, see our digital marketing services or get in touch.

Frequently Asked Questions

Is Universal Analytics still available?

No. Standard Universal Analytics properties stopped processing new data on 1 July 2023, UA 360 properties stopped on 1 July 2024, and Google has since ended access to UA reports and data. Use GA4 for all current measurement.

Can I migrate my old Universal Analytics data into GA4?

No. GA4 cannot import UA history. If you exported your data earlier, keep it for reference and use GA4 for everything going forward. Once GA4 has been collecting for a full year you can start comparing year over year inside GA4.

Why do my GA4 numbers not match Universal Analytics?

GA4 uses an event-based model and different definitions for sessions, users, engagement and attribution. Consent settings, bot filtering and thresholds can also change totals. Validate GA4 against real outcomes such as orders and leads instead of matching UA.

What replaced goals in GA4?

Goals became events, and the important ones are marked as key events, which used to be called conversions. You set them at property level instead of per view.

How long does GA4 keep data?

Event-level data is kept for 2 months by default and can be extended to 14 months on standard properties in the data retention settings. Standard aggregated reports are not affected by this setting.

Do I need Google Tag Manager for GA4?

No. You can add the Google tag directly to your site. Tag Manager is optional, but it makes it easier to add and test events without editing site code.

Is GA4 free?

Yes. GA4 is free for most websites and apps. A paid version, Analytics 360, exists for large organisations with higher limits.