What is an Event in Google Analytics 4?

If you've recently migrated from Universal Analytics to Google Analytics 4, you've probably noticed that things look a little different. The biggest change is how GA4 thinks about your website's data: nearly every interaction is now considered an "event." This article will unpack exactly what an event is in GA4, walk you through the four different event types, and show you how to use them to get a clearer picture of user behavior.

The Big Shift: Why Events Are Everything in GA4

In the old days of Universal Analytics (UA), data was primarily organized around sessions and pageviews. We would measure a user's visit (a session) and see which pages they looked at (pageviews). Other actions, like form submissions or video plays, had to be shoehorned in as different "hit types." It worked, but it didn't always reflect the user's actual journey, especially on modern websites and apps.

GA4 throws that model out the window. Now, everything is an event. A pageview is an event. A session start is an event. A click, a purchase, a scroll - they're all just events. This event-based model is more flexible and powerful, allowing you to track a continuous stream of user interactions without being constrained by the old session-based structure. It unifies measurement across websites and mobile apps, giving you a single, consistent way to see how users engage with your brand from start to finish.

The Four Types of GA4 Events

Understanding events in GA4 means knowing there are four distinct categories. Some happen automatically, while others require a bit of manual setup. Let's break them down one by one, from easiest to most flexible.

1. Automatically Collected Events

These are the events that GA4 tracks for you right out of the box, with absolutely no extra setup required as long as you've installed the base GA4 tracking code on your site. They form the foundation of your analytics and cover the most basic user interactions.

Here are some of the most common automatically collected events:

• first_visit: Tracks the first time a user visits your website or launches your app. It's great for understanding new user acquisition.
• session_start: Fires whenever a new session begins. A session is a period of time during which a user is actively engaged with your site. It starts a new session after 30 minutes of inactivity by default.
• user_engagement: This is a sophisticated event that helps measure actual engagement beyond just pageviews. It fires when a session lasts longer than 10 seconds, has a conversion event, or has at least two pageviews. It's GA4's answer to the flawed "bounce rate" metric.

You don't need to do anything to enable these - they just work. They provide essential context about user traffic and basic engagement levels without you lifting a finger.

2. Enhanced Measurement Events

Think of Enhanced Measurement as a set of sophisticated bonus trackers that you can turn on with a simple toggle switch. These events capture common, meaningful interactions that nearly every website owner wants to monitor. In old Universal Analytics, you would have needed Google Tag Manager (GTM) or custom code to track most of these.

Some of the most valuable Enhanced Measurement events include:

• scroll: Fires once per page when a user scrolls more than 90% of the way down. This is an excellent indicator that a user is highly engaged with long-form content like a blog post or landing page.
• click: Captures outbound clicks, which are clicks on links that lead users away from your domain. This helps you understand which external resources or partners you are sending traffic to.
• file_download: Tracks when a user clicks a link to download a file (like a PDF, ZIP, or DOCX). It's perfect for tracking downloads of white papers, case studies, or price lists.
• view_search_results: If you have a search bar on your site, this event fires whenever a user performs a search, helping you understand what your audience is looking for.
• video_engagement: If you have embedded YouTube videos on your site, this powerful feature automatically tracks video plays, progress, and completions.

How to Enable Enhanced Measurement Events

In most new GA4 properties, these are enabled by default. But it's always a good idea to check:

1. Navigate to your GA4 property and click Admin (the gear icon) in the bottom-left corner.
2. In the Property column, click on Data Streams and select your web data stream.
3. Under the Events section, you'll see a heading for Enhanced measurement. Make sure the toggle is on. You can click the gear icon to customize which specific events you want to track.

Just by flipping this switch, you get a much richer dataset about user engagement without diving into any code.

3. Recommended Events

Once you've got the basics covered, you'll likely want to track more specific actions related to your business goals. Before you start inventing your own events, you should always check Google's list of Recommended Events.

These are events with pre-defined names and parameters that Google has created for common scenarios across different industries, like e-commerce, travel, and gaming. The biggest advantage of using recommended events is that they're standardized. Because Google knows what purchase or sign_up means, it can unlock more sophisticated and detailed reporting features for those events in the future.

Here are just a few examples:

• For any business:
• For e-commerce:

By sticking to Google's naming conventions, you help GA4 understand your data better. This allows it to populate standard reports (like e-commerce reports) correctly and makes your data more comparable with industry benchmarks down the line.

4. Custom Events

Finally, we have custom events. A custom event is any event you name and implement yourself. You have complete freedom here. This is your go-to option when you need to track an interaction that isn't captured by automatic, enhanced, or recommended events.

Some examples of when you might need a custom event:

• Tracking clicks on a non-obvious, but important, button (e.g., "Compare Features").
• Measuring submissions for a newsletter signup form that doesn't direct to a new page.
• Monitoring interactions with a specific interactive tool or calculator on your site.

The golden rule is: Always check the first three categories before creating a custom event. If there's an existing event type that fits, use it. If not, go custom.

Example: Setting Up a Custom Event for Newsletter Signups

Let's say you want to track how many people sign up for your blog's newsletter. There is a recommended event called generate_lead, but perhaps you use that for your main service contact forms and want something separate for newsletter acquisitions. So, we'll create a custom event called newsletter_signup.

The easiest way to set this up is with Google Tag Manager (GTM):

1. Create a Trigger in GTM: You first need to tell GTM when to fire the event. This might be when a user submits the newsletter form or clicks the "Subscribe" button. You can use GTM's built-in Form Submission trigger for this.
2. Create a Tag in GTM: Next, create a new tag. Select "Google Analytics: GA4 Event" as the tag type.
3. Link the Tag to the Trigger: Attach the form submission trigger you created in step 1 to this new tag.
4. Save and Publish: Save your tag, preview/test it to make sure it's working, and then publish your GTM container.

Once you've done this, GTM will send the newsletter_signup event to GA4 every time a user subscribes. To make sure this data is fully usable in reports (especially if you want to add extra details to it), you should register any associated parameters as custom dimensions in the GA4 admin area.

Event Parameters: Adding Context to Your Events

An event name, like purchase, tells you what happened. But you also need to know the details! That's where parameters come in. Parameters are additional pieces of information sent along with an event to provide context.

For example, a purchase event is much more useful if it's sent with parameters like:

• currency (e.g., 'USD')
• value (e.g., 99.99)
• transaction_id (e.g., 'T-12345')
• items (an array of purchased products)

Many events, especially the automatic and recommended ones, come with their own pre-defined parameters. For your custom events, you can create your own custom parameters to send whatever extra information is valuable to you. For our newsletter_signup event, for instance, we could add a signup_location parameter to track whether the user signed up from the blog sidebar, a popup, or the footer.

Finding Your Event Data in GA4

Once you've set up your events, you’ll want to see the data. The primary place to look is the Reports > Engagement > Events report in the GA4 sidebar. This gives you a high-level overview of which events are firing most often and the number of users triggering them.

To go deeper, you'll need to use the Explore section. Explorations allow you to build custom reports, such as a Free Form report where you can drag and drop your Event Name alongside other dimensions (like Source/Medium or Page Path) and metrics to answer specific questions about user behavior.

Final Thoughts

Grabbing hold of the event-based model is the single most important step in mastering Google Analytics 4. It treats every user interaction, from a pageview to a purchase, as a single, consistent type of data point, creating a flexible and powerful foundation for understanding the entire customer journey. By understanding the four distinct types of events, you can build a robust measurement plan that gives you clear insight into what's actually happening on your site.

Pulling all this detailed event data out of GA4 and stitching it together with reports from your advertising platforms, CRM, and sales tools still takes a ton of manual work. That's actually why we built Graphed. We wanted to eliminate the need for endless CSV downloads and spreadsheet wrangling. We connect to all your data sources so you can use simple, natural language to ask questions like, "Build a dashboard showing which campaigns are driving the most newsletter_signup events" and get an answer complete with live charts in seconds.