Everything you need to know about Google Analytics 4

9 minute read

In 2020, Google Analytics announced its biggest change since it launched Universal Analytics in 2012: the introduction of Google Analytics 4 (GA4). In 2023, Universal Analytics officially stopped collecting data and GA4 took the wheel.

GA4 holds a lot of trepidation for marketers, but after working with the platform for the last couple of years, our Cornerstone Analytics experts are here to de-mystify the platform and empower you to make the most of GA4…

  1. What do we use GA for?
  2. Why has Google introduced GA4?
  3. UA vs GA4: The Key Differences
  4. Our GA-4 top tips

What do we use GA for?

At its most basic level, Google Analytics gives you free tools to understand your customers’ online journey in order to make informed decisions to improve your ROI.

The data Google Analytics gives us allows us to understand how customers are finding us online, how they’re engaging with your brand online, what they’re most engaged with, what they’re least engaged with and who they are.

From the collected data, we can report on and optimise our digital presence, measuring conversion rates, traffic patterns, and identify opportunities to generate new ideas.

A custom Cornerstone client GA4 report

A custom Cornerstone GA4 report

Why has Google introduced GA4?

As we move into a world free of cookies, GA4 has been introduced with privacy at the forefront. Because GA4 operates across all digital platforms, web and app, it doesn’t rely exclusively on cookies. It uses event-based data modelling for its measurement.

Under GDPR, websites require users to consent to cookies to track website performance but GA4 will start reducing this reliance on cookies to record certain events across web and app by using machine learning to ‘fill in the gaps’ where user consent is not given for tracking, making it more stable to industry changes and preventing future gaps in your data.

GA4 is built with the future in mind, so scalability and growth have been factored into the new design, along with a wider focus on tracking the complete user journey, as opposed to splitting user interaction into sessions, devices or platforms like Universal Analytics.

Google News results of GA4 privacy news shown on an iPad

UA vs GA4: The Key Differences

The most anticipated change from Universal Analytics (UA, or GA3) is the tracking potential on apps, and housing this in the same property as your web data.

GA4 leverages the same measurement model as Google Analytics Firebase (which the majority of app marketers use for tracking at the moment) where all interactions are captured as events. This new unified data schema between a website and a mobile app means that it will be much easier to combine data across them.

Another significant difference between UA and GA4 is how interactions are captured. In UA, interactions were captured in many different hit types such as page views, transactions, and social interactions. In GA4, every interaction is captured as an event.

In UA, a session is typically defined as having ended once there has been a 30-minute period of inactivity or another qualifying reset event has occurred. By contrast in GA4, the session_start event generates a session ID with which all subsequent events during the session are associated. The duration of a session is based on the time span between the first and last event in the session. In short, GA4 gives a more robust view of a user’s session.

There are some key metrics that have depreciated in the move to GA4 too… Bounce rate and average session duration are no more. Google has chosen to take a more “positive” approach by reporting in relation to ‘engagement’; engaged sessions, engagement rate and engagement time. The focus is now more on events and analysing how users are actively engaging with the site or app.

Google Tag Manager (GTM) is also now more important than ever. Tag Manager acts as a conduit between your website and Analytics account, giving the power to the marketer to setup custom events for tracking at an incredibly granular level.

In UA, you were able to setup events and conversions without GTM, for instance, creating conversion based on destination pages. This functionality is not available in GA4. All goals are event-based, thanks to the event-based modelling, so it is more important than ever to know your way around GTM to get your custom events setup in a way that works for you.

A few further differences can be seen below:

Universal Analytics (UA) Google Analytics 4 (GA4)
User-specific way of measuring data – who user is and where they’ve come from Focuses on what the user does rather than who the user is
Logs IP addresses Entirely anonymous
Uses a sessions and pageview-based model Events-based model – specific actions over who is performing them

Our GA-4 top tips

1. Setup Google Signals

UA came pre-loaded with a whole plethora of demographics and interest data but, obviously, with privacy front-of-mind, GA4 does not unless…

You activate Google Signals!

Signals is a Google product that launched in 2018 but it’s now more important than ever.

Signals feeds data from users who have turned on Google’s Ads Personalization feature directly into your GA4 property. This association of data with these signed-in users is used to enable cross-device reporting, cross-device remarketing, and cross-device conversion monitoring.1

It’s more robust than traditional BigQuery due to its ability to measure users across devices which gives your funnel analysis the edge as you can optimise user journeys at every stage. You can also focus on areas of the journey that are most valuable to the user by understanding behaviours based on the device combinations that they’re using.

While Google Signals gives us great insight, it does also have its limitations including:

  • Inability to integrate in custom reports and dashboards in GA4
  • Segmentation features are currently lacking in cross-device reports
  • Data is not exported to BigQuery
  • Inability to integrate in Data Studio reports

However, the cross-device insights Signals give us is incredibly valuable when applied to CRO strategies, remarketing campaigns, audience analysis and budget optimisation. By understanding users who are signed into Google accounts across devices, GA4 and Signals can give you more accurate demographic information and user characteristics. This data can help you refine target audiences and marketing comms to specific user segments, resulting in more effective campaigns and improved ROI.

2. Generate custom reports and dashboards

Setting up custom reports and dashboards in GA4 allows you to tailor your Analytics data to your specific needs and gain deeper insights into your website or app performance. Custom reports and dashboards offer a range of benefits, from visualising key metrics at a glance to analysing complex data sets in a more user-friendly format.

By selecting and organising relevant data points, you can create customised views in reports that match with your wider goals and objectives and focus on the metrics and dimensions that matter most to you. This then allows for more efficient analysis and reporting, as you can quickly access the most pertinent information and identify trends or patterns within reports you’ve created.

This all help with tracking and monitoring KPIs effectively. By consolidating relevant metrics into a single dashboard, you can track KPIs in real-time, making it easier to track progress, identify areas of improvement, and make data-driven decisions. The ability to customise the layout and timeframes of these reports and dashboards ensures that you have the flexibility to focus on the specific metrics that matter.

By sharing custom reports and dashboards with your wider team, agency or client-side, you can ensure that everyone has access to the same data and insights. This promotes transparency, aligns teams around common goals, and fosters a data-driven culture where decision-making is based on shared insights. Custom reports and dashboards also allow for the automation of reporting processes, saving time and effort while providing up-to-date information to all stakeholders.

3. Get comfortable with secondary dimensions

Using secondary dimensions in GA4 allows you to dig deeper into data and gain valuable insights by adding an additional layer of analysis to primary dimensions. Much like their function within UA, secondary dimensions provide context and granularity to metrics, allowing you to understand the relationship between different variables and uncover meaningful patterns and trends.

For example, by selecting a primary dimension, such as “Source/Medium” to see the sources referring traffic to site, and then adding a secondary dimension, such as “Device Category,” you can see how different traffic sources perform across various device types. This level of segmentation provides insights into user behaviour and helps identify which sources and devices drive the most valuable traffic, allowing for more targeted marketing strategies and optimisation efforts.

As in UA, secondary dimensions can help with data exploration and troubleshooting too. By applying secondary dimensions to primary dimensions, you’re able to drill down into specific data subsets and identify potential issues or opportunities. This analysis helps uncover areas for improvement, such as optimising content or improving user experience, ultimately leading to increased engagement and conversions.

4. Start thinking in terms of engagement

As we’ve explored earlier in this piece, GA4 has taken a very engagement-driven approach, so it’s time we started aligning our thinking with that!

Thinking in terms of engagement helps us to understand how involved and satisfied users are with the website or app. By analysing metrics such as engaged time on site, engagement rates, and event completion, you can identify areas for improvement and implement strategies to enhance user engagement, leading to increased conversions and user satisfaction.

Using this thought in conjunction with the data generated from Signals, you can start to segment your audience by engagement levels. Try to identify highly engaged user segments and create personalised on-site or in-app experiences, such as product recommendations or targeted campaign messaging, to further enhance their engagement and loyalty. By understanding the engagement patterns of different user segments, you can optimise multi-channel marketing campaigns, content strategies, and user flows to better resonate with your target audience.


1 https://support.google.com/analytics/answer/9445345?hl=en#zippy=%2Cin-this-article

If you’d like to discuss levelling up your GA4 Property with one of our Analytics experts, get in touch! We can help with anything from migrating you over from a basic GA4 setup to a robust GTM container, to setting up Google Signals and developing CRO strategies that boost your bottom line.

By Jess, Head of Digital

Jess Buckley

Jess joined Cornerstone as an account executive in January 2017 following freelance roles within marketing and PR fields. Exploring her passion for all thing digital, Jess embarked on several training courses and became Cornerstone’s dedicated digital marketer within 12 months of joining the Cornerstone team. Jess gets involved in all digital work at Cornerstone including […]

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