The Differences Between UA and GA4: An Ultimate Guide

Features and capabilities change with each version, and it can be difficult to understand them all.

To help you, we’ve created this ultimate guide to the differences between UA and GA4. First we’ll discuss the 5 key differences that you need to know. Then we’ll provide an overview of all other notable changes. 

Finally, at the end of the article, you can find a link for a handy downloadable quick reference guide to everything we’ve discussed in this article. 

What is Google Analytics?

Google Analytics provides information about your website and app traffic, including how many people visit, how long they stay, and whether they convert. These key metrics, along with countless others, are essential if you want to understand how your marketing and website are performing. 

When Will UA Become Obsolete?

Google understands how integral its analytics suite has become to businesses all across the world, so it has offered a lengthy transition window where UA and GA4 are both supported. It will also continue to develop GA4 during this time. 

Google’s end goal is for everyone to convert to GA4. That means that UA will become obsolete as of July 1st, 2023. In the meantime, you can continue to use UA, but it’s recommended that you complete your GA4 transition as soon as possible to take advantage of the following 5 key differences.

What are the 5 Key Differences Between UA and GA4?

Here are the 5 key differences that you need to know. They offer improved insights over UA and taking advantage of them is a reason to convert to GA4 as soon as possible. 

1. Measurement Model

The way Google Analytics organises its data into actionable metrics is through a measurement model. In UA, this measurement model is based on sessions and pageviews, which shows you how many people visit and how long they spend on your site. 

The GA4 measurement model is based on events, which can be anything from scrolling, clicking, and time spent on a page. This breaks the data down into smaller fragments which helps paint a more accurate picture of a user’s behaviour. 

Think of it as UA telling you when someone is present, while GA4 tells you what they are actually doing. 

2. Cross Platform Tracking

Cross-device and cross-platform tracking has traditionally been difficult for Google Analytics. UA and all previous Google Analytics versions have a different schema set up for different devices. This means the same user could visit your site on desktop and mobile, and appear as a new user each time. 

This is problematic for a number of reasons:

• You might think you are acquiring twice as many new users as you actually are
• A lot of people browse on mobile but purchase on desktop. In UA these transactions may be attributed to desktop, with mobile device acquisition receiving zero credit for the conversion.
• People might make smaller purchases on mobile, but save larger purchases for desktop, leading you to think your desktop customers are more valuable despite the fact they may be the same person

GA4 uses one schema to track all devices. This means your ability to track data across multiple devices, and your capacity for multi-channel attribution, are far better with GA4.

3. Bounce Rate and Engaged Sessions

Bounce rate is one of the catchiest metrics in Google Analytics, but its effectiveness as a tool has always been much less impressive than its name. 

It is supposed to tell you how many people visit your website and then immediately leave, which could signal poor load speeds or your website not being helpful for the customer. It does this by tracking when a person visits a page without interacting or navigating to another page before leaving. 

The problem is, there’s no time component to bounce rates. That means someone who visits a blog and spends a few minutes reading before leaving looks the same as someone who reads for one second before leaving. They’re both considered bounces.

GA4, on the other hand, introduces time and event based qualifiers. If a person spends at least 10 seconds on a page, or if they scroll, click etc, they are no longer classified as a bounce. This new metric is called an engaged session. Knowing the difference is essential for recognising when someone gets value from a page. 

4. Session Data

Due to UA starting a new session each time someone arrives through a different device or campaign source, its number of sessions metric is often inflated. Any time you see a high number of sessions, you need to factor in that a large portion of them may be returning users. 

With GA4, returning users won’t appear as new sessions, they’re sessions will continue each time they revisit. This, coupled with the new engagement rate means you can get a more detailed breakdown of how people behave during sessions. 

For instance, with UA you can only see how many sessions, whereas with GA4 you can see how many sessions, how many engaged (10 seconds or longer) sessions, and clearly identify new or returning visitors. 

5. User Data

Google Analytics tracks user numbers with Client IDs as a guide to the overall volume of your traffic. In UA, total users simply refers to the total number of people who visited your site. This doesn’t differentiate between someone who browsed for 10 minutes or someone who visited for mere seconds. 

GA4 recognises and fixes this problem. Its users metric tracks User IDs which report on engaged users. After converting, you may be startled by having fewer users, but don’t be concerned. The new User ID is simply filtering out the unengaged users, giving you a more accurate snapshot of the influence of your site. 

Remember, you are using Google Analytics to understand how your website is performing, not to read padded-out statistics. GA4’s user tracking shows you what you need to see, not just what you want to see. 

The Ultimate UA vs GA4 Quick Reference List

Here you can read a brief summary of the 35 most noteworthy differences between UA and GA4. 

1. The measurement model has changed from being based on sessions and pageviews to being based on events and activity
2. Cross-platform tracking is enhanced in GA4 because different devices now share the same schema
3. Bounce rates have been reduced in GA4 to only apply to a session that has failed to trigger an event such as scrolling, or that has left after less than 10 seconds
4. Bounce rates have been replaced by engage rates, which qualify an engaged sessions with time and event parameters, rather than just whether the user navigated the site or not
5. Session counting is now predicated on engaged sessions in GA4, rather than total sessions counting as was standard in UA
6. Total user numbers will appear differently across both iterations because UA doesn’t segment new vs returning users, but GA4 does
7. Tracking IDs have changed, with GA4 IDs starting with a G instead of a UA
8. User ID is used instead of Client ID for tracking user data in GA4
9. Unique characters are assigned to User IDs in GA4 to help recognise returning visits and cross-platform behaviour
10. App Instance ID replaces Client ID for mobile app users in GA4
11. The reporting interface will appear different due to some measurement instruments being renamed, removed or replaced
12. Multi-channel attribution is now more viable thanks to improvements in cross-platform tracking in GA4
13. ‘Hits are ‘Events’ in GA4, and the parameters that can be set for each hit are more customisable
14. Late hits can be tracked for longer in GA4 – up to 72hrs rather than UA’s ability to track them for 4hrs
15. Enhanced Ecommerce tracking is still being developed in GA4 and is far less comprehensive than in UA
16. Custom dimensions in GA4 have replaced the ‘Hit’ and ‘Session’ scopes with ‘Event’ to more accurately account user activity
17. Custom metrics in GA4 reflect the changes to dimensions, with all previously selectable scopes now being replaced by the ‘Event’ scope
18. Creating additional data views is no longer possible in GA4, but data streams for your site and apps is possible
19. Creating additional reporting views is no longer possible in GA4, but data streams for your site and apps is possible and can be used as alternatives
20. Event tracking is more flexible in GA4, with up to 25 possible custom parameters per event
21. Event scoped segment creation is now possible in GA4, rather than being limited to just user scopes segments in UA
22. Multiple conversion counting per session is now possible in GA4, whereas UA could only record one conversion per session regardless of how many conversions there actually were
23. Conversions that satisfy multiple conditions weren’t possible in UA because conversions had to be based around four established parameters, but in GA4 you can by creating custom audience triggers
24. Pageviews combine pageviews and screenviews in GA4, whereas UA only showed pageviews
25. Sessions are calculated differently, with GA4 using the event metric, and UA using the hits metric
26. Certain event tracking events are now automated, including scrolling, outbound clicks, video playback and downloads
27. Event data for inactive users can be retained for a customisable length of time before being deleted in GA4
28. Content grouping is created by adding a new group in UA, but in GA4 you’ll need to use the predefined parameter to auto populate the grouping
29. Funnel creation has been greatly improved in GA4, with the ability to create them easily and apply advanced segments which UA was not capable of
30. A new DebugView Report is available in the GA4 reporting interface which wasn’t possible in UA
31. A new Explorations report template suite has been added to the GA4 reporting space
32. IP anonymisation is enabled by default in GA4 and cannot be disable, unlike in UA
33. BigQuery is is a free connection through GA4, unlike in UA
34. Spam data prevention was lacking in UA, but has been addressed in GA4 by mandating that a secret key be used in all hits, which are only available for GA4 users
35. Web purchase counts remain unaltered, but for consistent data across GA4 and UA, make sure you are using a unique transaction ID value

Need Help Converting to GA4?

As you can see, the benefits of converting to GA4 outweigh the drawbacks. As the July 1st, 2023 obsoletion date draws closer, GA4 will continue to gain new features and improvements. 

If you’d like to convert your existing UA configuration to the new GA4 iteration, we can complete that process for you.

We’ll ensure that your transition is completed properly, and we can help answer any questions you have about the new version. 

Visit our website for more information about us, or to get in touch and schedule your transition to GA4.