In the dynamic world of digital analytics, moving away from what is familiar can often lead to a wave of confusion and questions. Such is the case with the evolution of Google Analytics 3 (GA3) to Google Analytics 4 (GA4). As businesses and website owners make the leap to GA4, they're finding that the metrics they once relied on have undergone significant changes. The seeming fluctuations in data and performance have raised queries: Has our website's traffic truly dropped? What could be the underlying cause?

However, the truth behind these apparent shifts is more nuanced than how it might initially appear.

The essence of these changes is related to a fundamental shift in data models between the legacy GA3 and the revolutionary GA4. While GA3 operated on sessions and pageviews, GA4 adopted a new paradigm based on events and parameters. This fundamental divergence in data collection and processing methodologies leads to differences in how the two analytics platforms collect and present information. In addition to a revised user interface, GA4 introduces new metrics, reports and features while omitting or changing some familiar aspects of its predecessor.

Let’s uncover the key differences between GA4 and GA3 to help you successfully adapt to updated analytics.

What is Google Analytics 4?

Google Analytics 4 is the latest version of the Google web analytics platform, designed to provide a more comprehensive and user-centric approach to tracking and analyzing website data. It represents a significant departure from its predecessor, Universal Analytics (UA) — also known as Google Analytics 3. GA4 introduces a new data model and advanced features in order to adapt to the ever-evolving digital landscape.

As we’ve already said, one of the most notable changes in GA4 is the move from a session-based model to an event-based model. This means that GA4 focuses on tracking individual user interactions (events) on a website or app, offering a more holistic view of user behavior and interaction. This new approach allows companies to gain a deeper understanding of the user experience, customer journey and cross-platform behavior.

GA4 also places a strong emphasis on user privacy and consent. It is designed to comply with data protection regulations such as the GDPR and CCPA, allowing businesses to collect and use data in a privacy-conscious manner. In addition, GA4 incorporates machine learning and predictive analytics to provide actionable insights and recommendations to help businesses make informed decisions to improve their online presence and user experience.

The platform's advanced reporting and real-time data analytics capabilities enable businesses to better understand user interactions, track conversions and optimize their online strategies.

GA3 vs. GA4 Reporting: Comparing Metrics

So, if you're here, you likely have already experienced certain metric fluctuations after moving to GA4. So, let's look at the metrics that cause the most questions: sessions, average session duration, bounce rate and conversions.

GA3 vs. GA4: Sessions

In both GA3 and GA4, a session represents a period of interaction that a user has with your website or app. However, sessions are indeed calculated differently in GA4 and GA3, and this difference may result in fewer sessions calculated in GA4 compared to the previous version.

GA3 (Universal Analytics) GA4 (Google Analytics 4)
Sessions are time-based. By default, a session ends after 30 minutes of inactivity. This means that if a user doesn't interact with your website for more than 30 minutes, their current session ends, and a new session begins once the user performs an action. Sessions are now more event driven and user centric. A session begins when a user engages with your site or app, such as clicking on a page, triggering an event or performing an action. The session may last for a longer period if the user remains active.

So, the key factors that contribute to lower session counts in GA4 compared to GA3 include:

  1. User-centric tracking: GA4 tracks user engagement and interactions more granularly, leading to a more accurate representation of how users are actually interacting with your content.
  2. No time threshold: Unlike GA3's 30-minute inactivity threshold, GA4 doesn't have a fixed session duration. Instead, it captures all events and user interactions within a specified time frame.
  3. No direct session count: In GA4, you won't see a direct Sessions metric. Instead, you'll see events and engagement metrics that provide a better understanding of user behavior.
  4. Event-based tracking: GA4 tracks events more comprehensively, allowing you to understand user actions beyond traditional pageviews.
  5. Cross-platform tracking: GA4 is designed to work across various platforms, including websites and apps, which might lead to different user interaction patterns.

Unlike GA3, where the default session timeout is set at 30 minutes but can be extended to a maximum of 4 hours, GA4 has an adjustable session timeout, allowing you to extend it to a maximum of 7 hours and 55 minutes. This impacts how user sessions are tracked. For example, in GA3, if someone stepped away from your website for five hours, they would indeed be counted as two separate sessions due to the maximum 4-hour session timeout. In GA4, with the extended session timeout, they would be counted as one continuous session, providing a more accurate representation of user engagement.

Important fact: In Google Analytics 3, sessions reset at midnight, creating multiple sessions if activity spans this time. In Google Analytics 4, session reset depends on your time zone setting, allowing for more accurate tracking of continuous user sessions, especially across different time zones.

GA3 vs. GA4: Average Session Duration

The difference between GA4 and UA in how average session duration is calculated is a reflection of the shift in tracking philosophy from sessions to user interactions.

GA3 (Universal Analytics) GA4 (Google Analytics 4)
The average duration of user sessions is calculated in seconds, regardless of whether your web page is in the foreground or in the background (excluding the time spent on the last visited web page). The average duration of engaged sessions is calculated in seconds and measured from the start of the initial session to the unload event.

In GA3, the average session duration is calculated by dividing the total duration of all sessions by the total number of sessions. It measures the average time users spend on your website during their sessions. However, because GA3 uses a fixed session duration (30 minutes of inactivity or end of day), sessions can be artificially shortened if the user leaves and returns after some time. If this is not properly understood, it can lead to inaccuracies in metrics for average session duration.

In GA4, this metric is calculated as the average duration of engaged sessions in seconds, measured from the start of the initial session to the unload event. This is a more accurate measurement because it directly tracks the time users spend actively on your website or app from the moment they start a session to the moment they leave or close the page.

It is important to note that in GA4, the definition of engaged sessions is more specific and tied to certain criteria. An engaged session in GA4 is a session in which:

  1. The user had 2 or more page views.
  2. The user has completed a conversion event.
  3. The user has reached a certain time threshold (e.g., 10 to 60 seconds) that you set.

Important fact: By default, most reports in GA4 do not include the Average Session Duration metric. Instead, you will see Average Engagement Time — the average length of time that the app was in the foreground, or the website had focus in the browser. You can add the Average Session Duration metric to your report by following these instructions.

GA3 vs. GA4: Bounce Rate

In both GA3 and GA4, the implementation of event tracking and other interaction events can affect how the bounce rate is calculated and interpreted.

GA3 (Universal Analytics) GA4 (Google Analytics 4)
Bounce rate is calculated as the percentage of single-page sessions (sessions with only one interaction) out of all sessions. Bounce rate is calculated as the percentage of not engaged sessions.

In GA3, if you have implemented a lot of tracking events, it's possible that users who interacted with events but not additional pages might be classified as engaged sessions rather than bounces. This can result in a lower bounce rate. On the other hand, websites with little to no event tracking may have a higher bounce rate, as any one-page sessions (even those with event interactions) will be counted as bounces.

In GA4, bounce rate is calculated based on the presence of engagement events, which are specific events you define as valuable interactions. These events can be counted as conversions. If an engagement event is counted as a conversion, then the session in which that event occurs will not be considered a bounce, even if it's a single-event session.

So, unlike in GA3, adding event tracking in GA4 does not directly impact the bounce rate, unless those events are counted as conversion events.

Important note: By default, most reports in GA4 do not include Engagement Rate and Bounce Rate metrics. To view these metrics in your reports, you need to customize the report. Read here for detailed instructions on how to customize your report.

GA3 vs. GA4: Conversions

In both GA3 and GA4, conversions refer to specific actions or events that you consider valuable on your website or app. However, there are some differences in how conversions are tracked and defined.

GA3 (Universal Analytics) GA4 (Google Analytics 4)
Conversions are typically tracked within the context of the session and can be deduplicated within the same session. Each instance of a conversion event is considered a separate conversion, regardless of session context.

In GA3, conversions were typically tracked in the context of sessions. If a user made a conversion multiple times during the same session (e.g., submitting a form), GA3 often deduplicated those conversions in that session. This means that if a user fills out the form multiple times in one session, GA3 will count this as one goal completion.

In GA4, each event, including conversions, is treated as a distinct action. That way, conversions are not deduplicated within the same session. If a user completes a conversion event multiple times, each instance of that event is counted as a separate conversion. As a result, if a user fills out the form multiple times on different occasions, each form fill is counted as a separate conversion in GA4.

Because of this difference, GA4 tends to report higher conversions compared to GA3 even without making any changes to website optimization. As such, moving to GA4 is a good opportunity to review and validate the accuracy of your conversion events, especially if they include forms or other actions that users may repeat during a session.

GA4 vs. Universal Analytics: Data Privacy

GA4 places a stronger emphasis on user privacy by default. It is designed to be more privacy conscious, aligning with evolving data protection regulations. GA4 encourages businesses to collect only necessary data and provide clear options for users to manage their preferences.

Here's a breakdown of how GA4 enhances user privacy:

  1. Use of first-party cookies: Both GA4 and UA use first-party cookies, which are set by the website the user is visiting. These cookies are not used to identify or track individuals but are instead focused on collecting aggregate data about website performance. This approach is more privacy friendly because it doesn't rely on third-party cookies that can be blocked by users or affected by ad-blockers.
  2. Reduced reliance on IP addresses: UA collected and stored IP addresses as part of its tracking process. In contrast, GA4 has minimized the use of IP addresses for user identification and tracking, reducing the privacy concerns associated with IP address collection.
  3. AI-powered tracking: GA4 incorporates machine learning and AI to help fill in gaps in data and identify trends or patterns in user behavior. This allows for more accurate insights without compromising individual user privacy.
  4. Enhanced consent management: GA4 provides tools for implementing and managing user consent for data collection and tracking. This is crucial for complying with privacy regulations and respecting user preferences.
  5. Customizable data retention: GA4 offers flexibility in data retention settings, allowing users to define their own data deletion rules based on specific events or timeframes. This empowers businesses to manage data retention in a way that aligns with their privacy practices and regulatory requirements.

Is Google Analytics 4 Better Than Universal Analytics?

Change is often difficult to accept. By now, you may be thinking that moving to GA4 is not the best choice. You aren’t alone in this. The interface has indeed undergone tangible changes and a lot will have to be relearned. However, as you become more familiar with the updates, you will realize that all the changes have been for your benefit.

Let's recap all the advantages of GA4 that we managed to talk about:

  1. User-centric tracking: GA4 focuses on user behavior and interactions across devices and platforms, providing a more comprehensive view of user journeys.
  2. Event-driven model: It offers a flexible event-driven tracking approach, allowing you to track a wide range of user actions beyond traditional pageviews.
  3. Enhanced user privacy: GA4 uses first-party cookies, emphasizes user consent and provides data retention controls, aligning with modern privacy standards.
  4. AI-powered insights: It leverages machine learning and AI to provide automated insights, helping businesses identify trends and opportunities more easily.
  5. Cross-platform tracking: GA4 excels in tracking user interactions across websites, apps and devices, offering a holistic view of user engagement.

In any case, transitioning to GA4 is a gradual process that may take time depending on the complexity of your analytics setup. It's essential to plan, test and continuously optimize your GA4 configuration to ensure it meets your business needs.

Google Analytics 4 vs. Universal Analytics Comparison Table

Feature GA3 GA4
Tracking model Pageview-centric tracking Event-driven tracking
User identity Relies on cookies and IP addresses Reduced reliance on IP addresses
Privacy focus Less emphasis on user privacy Strong emphasis on user privacy
Data retention Up to 26 months by default Up to 14 months by default
Cross-platform features Limited cross-platform tracking Enhanced cross-platform tracking
Session duration Fixed session duration (configurable) Adjustable session timeout (up to 7h 55m)
Integration Integration with Google products Integration with Google BigQuery
Custom reports Limited customization of reports More extensive custom reporting options

If you still have questions, you can always refer to Google Support.


What is the main difference between GA3 and GA4?

The main difference between UA and GA4 is the tracking model. GA3 relies on a pageview-centric approach, while GA4 uses an event-driven, user-centric model. This shift in tracking allows GA4 to provide more detailed insights into user behavior and engagement, making it more adaptable to modern digital analytics needs.

Is it possible to use GA3 and GA4 simultaneously?

No. As of July 1, 2023, GA3, also known as Universal Analytics, no longer gathers new data. This highlights the importance of transitioning to Google Analytics 4 or another modern analytics platform to continue tracking and analyzing website or app data effectively.

How do session definitions in GA3 and GA4 differ?

GA3 primarily relies on a time-based session definition. By default, a session ends after 30 minutes of inactivity and resets at midnight. GA4 employs an event-driven session definition. A session begins when a user interacts with your website or app and can extend as long as the user remains active. There's no automatic midnight reset, and the session timeout can be customized. This approach provides a more user-centric and flexible view of session durations.

What are the key features in GA4 that are not present in GA3?

Key features in Google Analytics 4 (GA4) that are not present in Google Analytics 3 (GA3) include:

  1. Event-driven tracking: GA4's event-driven model offers more comprehensive event tracking, allowing businesses to measure a wider range of user interactions.
  2. User-centric approach: GA4 focuses on individual user behavior, offering a more detailed view of user journeys and engagement.
  3. Flexible conversions: GA4 provides more flexibility in defining conversions, encompassing a broader range of user actions.
  4. Enhanced ecommerce tracking: GA4 offers improved ecommerce tracking with more detailed insights into online sales and product performance.
  5. Custom metrics and dimensions: GA4 allows users to create custom metrics and dimensions, providing greater flexibility in data analysis.
  6. Cross-platform tracking: GA4 excels in tracking user interactions across websites, apps and devices, offering a holistic view of user engagement.
  7. Improved user privacy: GA4 boasts enhanced user privacy features and a reduced reliance on IP addresses.
  8. No automatic midnight reset: Unlike GA3, GA4 does not automatically reset sessions at midnight, providing more accurate session duration tracking.

Can I migrate historical data from GA3 to GA4?

No, you cannot directly migrate historical data from Google Analytics 3 to Google Analytics 4. These two analytics platforms operate independently, and historical data collected in GA3 will not automatically transfer to GA4. To work with historical data in GA4, you will need to rely on data exports and manual data transfer processes, but it won't be a seamless migration of past data. Now, you can only transfer settings for users, events, goals, conversions and audiences.

Are there any changes in how conversions are tracked in GA4?

Yes, there are changes in how conversions are tracked in Google Analytics 4:

  1. More comprehensive conversions: GA4 offers a broader definition of conversions, allowing you to track a wider range of user actions as valuable conversions.
  2. Enhanced flexibility: You have more flexibility in defining what constitutes a conversion, making it easier to measure specific user interactions that matter to your business.
  3. Event-driven conversions: Conversions in GA4 are closely tied to user events, aligning with GA4's event-driven tracking model.
  4. Detailed path to conversion: GA4 provides a "Path to Conversion" report, offering insights into the sequence of user interactions leading to conversions, helping you understand user journeys more comprehensively.


The evolution of Google Analytics from its previous version, GA3, to the latest iteration, GA4, represents a significant leap forward in the world of web analytics. This transition marks a response to the evolving digital landscape, where user privacy, cross-platform tracking and a more event-driven approach to data analysis have become paramount.

Although transitioning from GA3 to GA4 may present certain challenges, the potential for more nuanced insights, improved privacy compliance and a user-centric approach to data analysis makes this transition a worthwhile investment in the future of web analytics. By embracing GA4, businesses can stay at the forefront of understanding and catering to their audience's ever-changing needs in the digital realm.