What is an Event in Google Analytics?

Every time a user does something on your website - watches a video, clicks a button, fills out a form - they’re leaving a clue about what they find valuable. Google Analytics 4 uses "events" to capture these clues, helping you understand user behavior far beyond simple pageviews. This article breaks down everything you need to know about GA4 events, including what they are, the different types, and how to set them up to measure what truly matters for your business.

What Exactly Is a Google Analytics Event?

An event in Google Analytics is any distinct user interaction on your website or app that can be measured. Think of it as an action. While a pageview tells you where a user went, an event tells you what they did when they got there.

This is a major shift from the old Universal Analytics (UA). In UA, the standard unit of measurement was the "session," which focused on pageviews. Events were a special tracking type you had to configure with a rigid "Category, Action, Label" structure. In GA4, everything is an event. From the moment someone first visits your site (first_visit) to when they start a session (session_start) or buy a product (purchase), every interaction is captured as a distinct event.

This event-based model is far more flexible and gives you a much more detailed picture of the user journey. It moves beyond just tracking page visits to tracking a continuous stream of interactions, which is more representative of how people actually use websites today.

Why GA4 Events Are Crucial for Your Business

Understanding and using events is non-negotiable for getting meaningful insights from GA4. They are the building blocks of modern analytics for a few key reasons:

• You Define What Matters: The old model forced you into a box. The GA4 event model hands you the tools and says, "What actions are most important for your business? Let's track those." Whether it's signing up for a newsletter, using a pricing calculator, or clicking on an affiliate link, you can track it as an event.
• Deeper Engagement Insights: Are users just passively viewing your pages, or are they actively engaging? Events answer this question. You can track scroll depth to see if people are reading your content, video plays to measure content engagement, and form submissions to capture leads. These actions provide a multidimensional view of engagement that pageviews alone cannot offer.
• Foundation for Conversion Tracking: The most important events, like a purchase or lead, are marked as "conversions." By tracking key events, you're building the foundation to accurately measure your business goals and understand which marketing channels drive the results you care about.

The Four Types of Events in GA4

GA4 organizes events into four distinct categories. Understanding these is essential for knowing what's being tracked out-of-the-box versus what you need to configure yourself.

1. Automatically Collected Events

These are the events that GA4 tracks by default as soon as you install the base code on your site. You don't have to do anything extra to enable them. They provide baseline data about user activity.

Common examples include:

• session_start: Fired when a user begins a new session.
• first_visit: Recorded the first time a user visits your site.
• user_engagement: Fires periodically when your site is in the foreground or when a user is on a page for more than a few seconds. This is how GA4 measures "engaged sessions."
• scroll: Automatically tracks when a user scrolls 90% of the way down a page. This used to be a complex custom setup in UA but is now standard.

2. Enhanced Measurement Events

Enhanced Measurement allows you to track more complex user interactions with just the flick of a switch - no coding required. You can enable or disable these directly within your GA4 Data Stream settings. By default, they are usually all turned on for new properties.

These powerful events include:

• Outbound clicks (click event with an outbound parameter): Tracks when a user clicks a link that leaves your domain.
• Site search (view_search_results): Captures data whenever a user performs a search on your website, showing you the terms they searched for.
• Video engagement (video_start, video_progress, video_complete): Tracks interactions with embedded YouTube videos on your site, as long as JS API support is enabled in your embedded videos.
• File downloads (file_download): Automatically logs an event when a user clicks a link that ends in a common document extension (e.g., .pdf, .docx, .zip).

To check or modify your Enhanced Measurement settings, go to Admin > Data Streams > Click your stream > and look for the 'Enhanced measurement' section.

3. Recommended Events

Google provides a list of pre-defined event names and parameters for common scenarios, categorized by industry (like e-commerce or gaming) or more general use cases. While you could name a purchase event whatever you want (e.g., completed_sale), using Google's recommended name (purchase) ensures that GA4 understands what the event means.

Why use them? Adhering to these conventions allows your property to benefit from Google's machine learning and future reporting capabilities because Google recognizes the event's purpose. It’s like speaking a common language with the platform.

Examples of recommended events include:

• For E-commerce: add_to_cart, begin_checkout, purchase, refund
• For Lead generation: generate_lead, sign_up
• For All Properties: log_in, share, generate_lead, tutorial_begin

You still have to set these events up yourself (usually with Google Tag Manager), but you should use Google's naming scheme whenever it fits your use case.

4. Custom Events

This is where you have total freedom. A custom event is an event that you name and implement yourself because it's specific to your business and not covered by the other three categories.

If there's an action on your site you want to measure, and it's not detected automatically or recommended by Google, you create a custom event.

Examples might include:

• Tracking clicks on a "Request a Call Back" button (e.g., event name: request_callback_click).
• Measuring interactions with a product configurator (e.g., customize_product).
• Logging when a user expands an FAQ (e.g., faq_expand).
• Tracking submissions for a non-standard contact form.

Parameters: The Data Behind Your Events

An event on its own is simply a record that something happened. The real value comes from the parameters sent along with each event. Parameters are additional pieces of information that give context to the event.

Think of it this way:

• Event: add_to_cart
• Parameters: item_name (T-shirt), item_id (SKU123), price (24.99), currency (USD)

Without parameters, you’d only know that some product was added to a cart. With parameters, you know exactly which product, its ID, and its price. Every event, including the automatically collected ones, comes with some default parameters like page_location (the URL) and language.

When you create custom events, you also define custom parameters relevant to that event. To use these custom parameters in your GA4 reports (e.g., see them in exploration reports), you must register them as "custom dimensions" or "custom metrics" in the GA4 interface under Admin > Custom definitions.

How to Create Custom Events in GA4

While some events are automatic, the most valuable events specific to your business need to be set up manually. Here are the two primary methods for doing so.

Method 1: Creating an Event Within the GA4 Interface

This is an easy, "no-code" way to create a new event based on an existing one. It's perfect for when the action you want to mark as an event is already being captured by another event, like a page_view.

Example: Create a new generate_lead event every time someone visits your thank-you.html confirmation page.

1. Navigate to your GA4 Admin panel.
2. Under the Property column, click on Events.
3. Click the Create event button.
4. In the configuration panel, name your new event. Let's call it generate_lead.
5. Now, set the triggering conditions. We create this event when two conditions are met:
6. Click Create. Now, whenever GA4 records a page_view for your thank-you page, it will also log a brand-new generate_lead event.

Method 2: Using Google Tag Manager (The Most Powerful Method)

Google Tag Manager (GTM) gives you much more control and is the recommended way to set up most custom events, especially those based on clicks, form submissions, and other page interactions.

Example: Track clicks on your "Download Our Annual Report" button.

Let's assume this button has the CSS class btn-download-report.

1. Create a Trigger in GTM: The trigger tells GTM when to fire an event.
2. Create a Tag in GTM: The tag tells GTM what to do when the trigger condition is met — in this case, sending an event to GA4.
3. Link the Tag and Trigger: In the Tag configuration, assign the Trigger you just created.
4. Preview, Test, and Publish: Use GTM's Preview mode to click your button and ensure the tag fires correctly. Once confirmed, publish your GTM container.

Final Thoughts

Moving from a pageview mindset to an event-based mindset is the single most important adjustment for getting value out of GA4. By focusing on the actions users take, you gain a crystal-clear understanding of what's working on your site and can optimize for the behaviors that actually drive growth.

Once you’ve set up your event tracking, the next challenge is connecting that data to everything else. This is where we built our product to shine. Analyzing user actions in Google Analytics is helpful, but seeing how those actions connect to your ad spend on Facebook, your customer data in Salesforce, and your revenue in Shopify is the complete picture. With Graphed, you can connect all your data sources in seconds and ask questions in plain English like, "What was our cost per generate_lead event from Facebook Ads this month?" to instantly build reports and dashboards that help you make better, faster decisions.