Google Analytics 4 vs. Universal Analytics: Top 10 Changes
Key differences between GA UA and GA 4 including reporting limitations, parameter character limits, and reporting filtering workarounds.
I have been working with Google Analytics (Universal Analytics/360/4) for the last 15 years. I have customized countless new website implementations, modified existing tracking setups, and replicated customer implementations in other tools like Adobe Analytics. In the past two years, I've migrated companies with multiple web properties from Google Analytics Universal Analytics (also known as v3) to Google Analytics 4.
Disclaimer: Please note that all Google Analytics Universal Analytics services will cease on July 1, 2024 and you should export your data prior to that date.
Here are the biggest changes I've seen between Google Analytics Universal Analytics and Google Analytics 4 from a growth marketing and digital marketing perspective.
1: Different Interface & New Report Limitations
The biggest immediate adjustment is that the Google Analytics 4 interface is significantly different from the previous Google Analytics Universal Analytics interface, starting with the left-hand navigation. Many standard reports have changed or are no longer displayed the same way such as traffic channel or page view reports. Default reporting dimensions (ie. page location now defaults to page path and screen class) are different and certain metrics no longer exist under the new event-focused Google Analytics 4.
For default reports, filtering is limited to "contains" for primary dimensions, and Google Analytics no longer offers additional filtering options ("does not contain", "starts with...") or even regular expression logic within default reporting.
There are multiple ways to replicate previous legacy reports from Google Analytics Universal Analytics with new custom reports offered by GA 4 (see below) but it's still a marked adjustment to Google Analytics 4's new reporting interface and this is a notable adjustment, especially for users used to certain interfaces and functionality from GA UA.
2: Event-Driven Model & Different Metrics
Google Analytics 4 gets rid of the previous page vs. the event-based model of Google Analytics Universal Analytics, instead treating all calls to GA as events. This comes from Google Analytics 4 being the standard implementation framework for app event tracking.
On the positive side, this means no longer worrying about what metrics are page/event compatible (a challenge when working with Google Analytics UA's API). Unfortunately, this also removes common metrics from standard reports many companies may rely on for reporting like unique pageviews or sessions.
In the migrations from GA UA to GA 4 I've completed (before GA UA was sunset) I've compared similar metrics across GA UA and GA 4. When implemented correctly (for example, standardized via Google Tag Manager), user metrics between versions in my experience are within a 3%-5% margin of error but session counts (and unique events / unique pageviews) will vary more significantly. For companies that use many UTM parameters on links within their websites, sessions will be significantly lower in GA v4 since GA UA counts every visit from a UTM string as a new session, while GA 4 does not.
I highly recommend standardizing website reporting to user metrics for GA 4 as the primary reporting metric for website traffic as this is more future-proof and will make comparisons across GA UA data more reliable.
3: More Event Parameters
Google Analytics Universal Analytics was previously limited to 4 event parameters - custom attributes to send data on the events that fired. Previously, these were Event Category, Event Action, Event Label, and Event Value (optional). Google Analytics 4 allows significantly more parameters to be attached to events (up to 25 total) which is great for collecting more data on website activity.
However, be forewarned that any new parameters you implement must be added in the Google Analytics 4 configuration screen (Custom Definitions) as new event parameters. For example, if you pass in a new event parameter called "eventType" with event calls to GA, you will not see this attribute in any reports, even if you correctly send it to GA 4 unless you add it into the Custom Definitions screen.
Confusingly, you WILL see these parameters and values in real-time reporting, but they will not be available or saved in standard or custom reports until they are added via the Custom Definitions screen.
4: Field Limits
Event Name Limits
Custom event names must be 40 characters or less. If your custom event parameter is over 40 characters this will impact your ability to flag the event as a conversion.
Event Value Limits
One of the biggest changes (and limitations) of Google Analytics 4 is new hard limits on the character counts for custom fields (such as event parameters). For example, while GA 4 allows for up to 25 custom event parameters, the values for these fields cannot be more than 100 characters, whereas Google Analytics Universal had no such limit.
Unfortunately, 100 characters is not a lot and I've already seen this impact custom field values for customers who have migrated their existing Google Analytics Universal tracking without considering this. Any event parameter values past 100 will be truncated, potentially leading to incomplete reporting.
For example, companies that integrate 6sense with Google Analytics 4 and want to send a list of applicable customer segments to GA for analysis will see that the values are fragmented in Google Analytics 4 compared to Google Analytics Universal Analytics.
Let's say you use a custom parameter called "6senseSegments" in GA UA and also want to use this in GA 4.
- In GA UA this string would reflect the full range of values
- "Consideration, High-value, Enterprise, SaaS, Competitive Intelligence Campaign, Retargetting, Existing Customer, Churned Customer"
- In GA 4 however, this string would be truncated
- "Consideration, High-value, Enterprise, SaaS, Competitive Intelligence Campaign, Retargetting, Existi"
The full list of field name end event limits is in this Google Analytics 4 support article.
5: Reporting Limits
Google Analytics Universal Analytics previously showed up to 5000 rows of data in a default report screen (and exported this easily to Excel or CSV). The default reports in Google Analytics 4 only show up to 250 rows per screen, while custom reports show only up to 500 rows per screen. You can work around this by using GA 4's API but it's another considerable limitation in the default UI reporting functionality.
6: Built-In Tracking for Common Use-Cases
Google Analytics 4 now has the option to automatically track website events like page scrolls, clicks to external URLs, form interactions, video engagement, and file downloads like PDF files.
Google automatically collects specific event parameters for these, such as the name of the file downloaded. However, these must be added as parameters in the Google Analytics interface in the Custom Dimensions screen, and DO count towards the 50 total unique event parameter limit and 25 unique user parameter limit, as well as the 100 character max for character field custom event field values. For example, if you have a long path for your downloadable file, and want to collect this, the value for this field will be truncated and not represent the full path.
This Google Analytics 4 This GA4 documentation link shows all the event fields collected with these built-in events.
7: No Customized Reporting Views or Filters
Google Analytics 4 no longer offers multiple Google Analytics report views or the ability to customize multiple custom profile filters. Common filter use cases such as excluding certain IP addresses have been replaced and the ability to use filters to modify page locations (for example, to include hostname or automatically lower-case values) is no longer possible.
To replicate these field value changes requires customizations to your GA 4 implementation.
One customer I worked with wanted "clean URL reporting" - page locations without parameters but including the hostname (ie. domain.com/path in reports) instead of using GA 4's default page location/page screen reporting. Unfortunately, the contractor that implemented this didn't realize that UTM values would be impacted (since these appear as URL parameters) rendering all their traffic as "direct".
I modified the implementation to automatically parse out UTM values in Google Tag Manager and send these in the correct built-in GA fields which ultimately gave them their preferred reporting view. As a fail-safe, we also created another custom event field for URL parameters.
8: Greater Reliance on Custom Reports & Custom Implementation
Because of the limits on default reporting I now run most reporting in Google Analytics 4 via custom reports. These allow multiple filters, including regular expression filters on reporting. In some cases, I've used BigQuery or Looker for reporting, especially when trying to combine multiple fields and dimensions in one single report view.
As mentioned previously, Google Analytics 4's removal of custom report views and new parameter value limits also pushes a bigger onus on custom implementation than I have previously seen with Universal Analytics. Until recently, Google Analytics 4 didn't offer a way to exclude specific URL parameters in data collections (these had to be manually removed in the implementation from being sent to Google Analytics). A few months ago Google added this functionality back in.
The custom event parameter value limits also require some potential implementation adjustments. In Google Analytics Universal Analytics I used to hash user emails and pass these to Google Analytics in one custom field. In Google Analytics 4 however, I have to use two separate dimensions as some email strings may be truncated.
9: New Report Types
On the bright side - GA 4 does offer new reporting that previously didn't exist in Google Analytics Universal Analytics.
Funnel Reporting
Previously this was only available in Google Analytics 360. This is arguably one of the most useful new reports in Google Analytics 4, making it easy to compare website funnels across users or traffic segments and making funnel reporting for a/b testing much easier.
User Pathing
GA UA did previously offer a previous/next page report, but now Google Analytics 4 provides a much more detailed user path reporting showing the starting page and most common next pages in a user journey. While this still falls short against more enterprise tolls like Adobe Analytics Ultimate (previously Omniture Discover) this has better functionality than GA UA offered.
10: Limited Third-Party Integration Support
Google Analytics Universal Analytics has been ubiquitous for so many years that many third parties still do not have GA 4 integrations, or integrations that do exist don't have as much functionality as GA UA.
This is notable for example in the GA4 Reports Build Google Sheets Plugin, which uses GA 4's API to easily export more data than you could via the visual interface. Notably, even this plugin created by Google has significantly worse functionality than the same previous GA UA sheets plugin which allowed for auto-scheduling reports and much deeper segmentation including the use of advanced segments.