GA4 Key Events: Setting Up Conversions That Actually Matter

Google renamed conversions to key events in March 2024, and the confusion hasn’t stopped since. However, the name change is the least of your problems. Most GA4 setups I audit have the same issue: too many “conversions” that don’t actually measure business outcomes.

If everything is a conversion, nothing is. Let’s fix that.

What Changed: Conversions Are Now Key Events

In early 2024, Google split what used to be called “conversions” into two distinct concepts:

• Key events — significant user actions tracked in GA4 (formerly called conversions)
• Conversions — now reserved exclusively for Google Ads, measured when a key event is imported into your Ads account

The reason? Google wanted to align GA4 reporting with Google Ads reporting. Previously, the same word meant slightly different things in each platform, and attribution models differed. As a result, marketers saw conflicting numbers between GA4 and Google Ads.

In practical terms, if you don’t run Google Ads, you’ll work with key events exclusively. The setup process is identical to how you previously configured conversions — only the label changed.

Why Most GA4 Goals Are Set Up Wrong

Here’s what I typically find when auditing GA4 properties: 15 to 20 events marked as key events, including things like scroll, click, page_view, and video_start. The dashboard lights up with thousands of “conversions” daily — and none of them mean anything.

The core problem is confusing engagement signals with business outcomes. A scroll to 90% of a blog post is interesting. It is not a conversion. Similarly, clicking an outbound link might be worth tracking as an event, but marking it as a key event dilutes your data.

Consider this distinction:

Track everything as events. However, only mark the macro-conversions — the ones tied to revenue or leads — as key events.

Identifying Meaningful Key Events for Your Site

The right key events depend entirely on your business model. Before touching GA4, answer one question: what action on your website directly generates or leads to revenue?

Here’s a quick framework:

• E-commerce: purchase, begin_checkout, add_payment_info
• SaaS / Software: sign_up, trial_start, upgrade_plan
• Lead Generation: generate_lead, form_submit, book_demo
• Content / Publishing: newsletter_signup, paid_subscription
• Local Business: click_to_call, request_directions, book_appointment

Most sites need between 3 and 5 key events. If you have more than 7, you’re probably tracking micro-conversions as key events. That said, there’s no absolute rule — just make sure each key event represents a meaningful business action.

For a deeper look at which metrics actually matter for your site type, see my guide on the top 5 website metrics that matter.

Step-by-Step: Setting Up Key Events in GA4

There are two ways to mark an event as a key event in GA4: directly in the GA4 interface, or through Google Tag Manager. Let’s start with the simpler approach.

Method 1: Mark Existing Events as Key Events in GA4

If the event already fires in GA4 (either automatically collected or custom), follow these steps:

1. Open your GA4 property and navigate to Admin (gear icon, bottom left)
2. Under the Data display section, click Events
3. Find the event you want to promote — for example, generate_lead
4. Toggle the switch in the Mark as key event column to the right of the event name
5. The event now appears under Admin > Key events and in your standard reports

That’s it. GA4 will start counting every future occurrence of that event as a key event. There’s no retroactive application, though — it only counts from the moment you toggle it on.

Method 2: Create a New Event in GA4 and Mark It

Sometimes you need to create an event from existing data. For instance, you might want a key event when someone views a specific “thank you” page:

1. Go to Admin > Events > Create event
2. Click Create
3. Name your custom event (e.g., lead_form_complete)
4. Set matching conditions: event_name equals page_view AND page_location contains /thank-you
5. Save the event, then return to the Events list
6. Once the new event appears (may take 24-48 hours), toggle it as a key event

Setting Up Key Events via Google Tag Manager

For more complex tracking scenarios, Google Tag Manager gives you far greater control. This is especially useful when you need to track button clicks, form submissions from third-party tools, or custom JavaScript-driven interactions.

Here’s how to send a custom event to GA4 via GTM:

1. Create a trigger in GTM — for example, a Form Submission trigger filtered to your lead form’s ID
2. Create a GA4 Event tag:
   • Tag type: Google Analytics: GA4 Event
   • Measurement ID: your GA4 ID (e.g., G-XXXXXXXXXX)
   • Event name: generate_lead
   • Optionally add event parameters like form_name or lead_value
3. Attach the trigger to the tag
4. Test in Preview mode — submit your form and verify the event fires in the GTM debug panel
5. Publish the GTM container
6. Go to GA4 Admin > Events and mark generate_lead as a key event once it appears

If you’re new to GTM’s data layer concept, I recommend reading my guide on the data layer in Google Tag Manager first. It explains how events and variables flow from your website into GTM.

Verifying That Key Events Fire Correctly

Setting up key events is only half the battle. Verification prevents you from making decisions based on broken data. Use these three methods:

1. GA4 Realtime Report
Navigate to Reports > Realtime. Trigger the conversion action yourself (submit a form, complete a purchase). You should see the event appear within seconds under the “Event count by Event name” card.

2. GA4 DebugView
Enable debug mode by installing the Google Analytics Debugger Chrome extension. Then go to Admin > DebugView in GA4. You’ll see a timeline of events as they fire, including parameters. Key events are highlighted with a green flag icon.

3. Google Tag Manager Preview Mode
If you used GTM, click Preview in your GTM workspace. Perform the conversion action on your site. In the debug panel, verify the tag fired and check the event parameters passed to GA4.

> Always test from an incognito window to avoid interference from browser extensions or cached states.

Conversion Attribution in GA4

GA4 uses data-driven attribution by default. This means it distributes credit for a key event across multiple touchpoints in the user’s journey, rather than giving all credit to the last click.

For example, a user might:

1. Discover your site through organic search
2. Return via a social media link
3. Finally convert after clicking an email campaign

In a last-click model, email gets 100% credit. With data-driven attribution, GA4 distributes credit based on how influential each channel was. Therefore, you get a more accurate picture of what’s driving conversions.

You can change the attribution model under Admin > Attribution settings. However, I recommend sticking with data-driven unless you have a specific reason to switch. It’s generally the most accurate option for most businesses.

For a deeper understanding of how users move through your site before converting, check out my funnel analysis guide.

Reporting on Key Events

Once your key events are collecting data, GA4 surfaces them in several places:

• Acquisition reports: See which channels drive the most key events
• Engagement > Events: View all events with key events highlighted
• Explorations: Build custom funnels and path analyses using key events as endpoints
• Advertising snapshot: If you link Google Ads, see how campaigns drive conversions

The most useful report is typically the Traffic acquisition report with the key events column added. This tells you exactly which channels produce business results — not just traffic.

Additionally, you can create custom audiences based on key events. For instance, build an audience of users who triggered generate_lead but never triggered purchase. Then export that audience to Google Ads for remarketing. Consequently, your ad spend targets people who already showed buying intent.

Common Mistakes to Avoid

After helping dozens of businesses configure GA4, these are the mistakes I see most often:

1. Too Many Key Events

If you have more than 5-7 key events, you’re almost certainly tracking things that aren’t business outcomes. Every additional key event adds noise to your reports. Strip it back to what directly affects revenue. In fact, Google recommends keeping the number low for exactly this reason — refer to the official GA4 key events documentation for guidance.

2. Counting Micro-Conversions as Macro-Conversions

A scroll event or video_start is not a conversion. These are engagement metrics. Track them as regular events and analyze them in your engagement reports. Marking them as key events inflates your conversion numbers and makes your actual conversion rate meaningless.

3. Not Setting Conversion Values

If you know the monetary value of a lead or sale, add it as a parameter. Go to Admin > Key events, click your key event, and enable Default value. This enables revenue-based reporting and helps you calculate ROI across channels. Without values, you’re counting conversions but have no idea which ones matter most financially.

4. Forgetting to Test After Setup

I’ve seen key events that were set up months ago and never actually fired — because the trigger conditions were wrong, the form changed, or the page URL was updated. Test monthly. Set a calendar reminder.

5. Ignoring Cross-Device Behavior

GA4 handles cross-device tracking through Google signals and User-ID. Make sure at least one of these is enabled, otherwise you’ll double-count conversions from users who browse on mobile and convert on desktop.

Bottom Line

GA4 key events are the backbone of meaningful analytics. However, they only work when you’re intentional about what you track. Stick to 3-5 key events that represent real business outcomes, verify they fire correctly, and review them regularly.

The rename from conversions to key events was cosmetic. The real work — defining what a conversion means for your business — hasn’t changed. Get that right, and GA4 becomes a genuinely useful tool instead of a dashboard full of meaningless numbers.

For guidance on tracking implementation beyond key events, explore my comparison of server-side vs client-side tracking to ensure your data collection itself is reliable.