GA4 Key Events: How to Track the Actions That Matter

Your GA4 property may be full of events, but you still can’t say how many leads or sales your site brought in last month. The fix is GA4 key events. A key event is any event you mark as important to your business, such as a purchase, a form submission or a booked call. Once you mark it, GA4 counts it on its own and shows it across your reports. So you can see which channels and pages really bring results.

In this guide I cover what key events are, how they differ from conversions, how to set them up, which events to choose, and how to test them before you trust the numbers.

What Are GA4 Key Events?

GA4 records almost everything as an event: page views, scrolls, clicks, video plays, form starts. Most of these describe behaviour. A few describe outcomes, and those are the ones you mark as key events. In my view, those outcomes should also lead your list of SEO KPIs.

Marking an event doesn’t change how it’s collected. It tells GA4 to treat that event as a success metric. That turns on the key events column in acquisition reports, the session key event rate and user key event rate metrics, and attribution reporting (how GA4 gives credit to each channel).

Any event you collect can become a key event. GA4 also marks purchase as a key event by default on websites, so online shops start with one already in place.

Key Events vs Conversions: What Changed in 2024

Until March 2024, GA4 called these “conversions”. On 21 March 2024, Google announced it was renaming them to key events. The reason was confusion. GA4 and Google Ads both used the word “conversion”, but each counted and credited it differently. So the numbers rarely matched.

Since the change, the two terms mean different things:

• Key event: an Analytics event you’ve marked as important. It shows up in standard GA4 reports and measures behaviour across all channels.
• Conversion: a Google Ads conversion. You can create it from a key event. It’s used to measure ad results and guide bidding. In GA4 it shows up in the Advertising section, not in standard reports.

Your existing conversions were renamed for you. If you were already sending them to Google Ads for bidding, you didn’t need to change anything.

How to Mark an Event as a Key Event in GA4

You need Editor access or above at the property level to mark an event. In the current layout, events live in Admin > Data display > Events.

1. Open Admin and, under Data display, click Events.
2. Find the event on the Recent events list. Events only show up here after GA4 has received them.
3. Click the star icon next to the event. It’s now a key event.

The event may not have fired yet, for example because you’ve just added a new tag. You can still create it as a key event ahead of time, by name. GA4 will treat it as a key event as soon as it starts arriving. Google’s help page on marking events as key events covers both ways.

Two points catch people out. First, marking an event only affects data from that moment on. Past events are not changed. Second, standard reports can take up to 24 hours to show a newly marked key event. Realtime shows it within minutes.

The Limit: 30 Key Events per Property

A standard GA4 property can have up to 30 key events, and an Analytics 360 property up to 50. That sounds like a lot, but I don’t think you should be anywhere near it. More on that in the mistakes section.

Creating Key Events From Existing Events

Often the event you want doesn’t exist on its own. A contact form might send you to a thank-you page, but GA4 only records a general page_view. Marking every page view as a key event would be useless. So you create a narrower event instead.

GA4 lets you do this without touching code:

1. Go to Admin > Data display > Events and click Create event (Marketer access or above).
2. Name the new event, for example contact_form_thanks. Use letters, numbers and underscores only.
3. Turn on Mark as key event. Choose a default value and counting method if you want them.
4. Choose to create it without code. Select page_view as the source event, and add a matching condition such as page_location contains /thank-you/.
5. Save. The original page_view keeps collecting as normal. GA4 makes a copy whenever the condition matches.

Some practical tips:

• Create, don’t modify. Creating an event copies the source event. Modifying an event overwrites it, and modifying page_view can break your page view data.
• Make the condition specific. “Contains thank-you” will also match a blog post called “thank-you-email-templates”. I match the full path where I can.
• It doesn’t apply to the past. Created events only start from the time you save them.

This approach works well for simple cases. Some actions don’t load a unique URL, such as an AJAX form (a form that submits without loading a new page), a click-to-call button or a chat widget. For those, it’s more reliable to send a dedicated event through Google Tag Manager or your site code. Then mark that event as a key event.

Recommended Events for Lead-Gen and E-commerce Sites

Google publishes a list of recommended event names. I always use them rather than inventing my own. That way GA4 knows what the event means and can fill its built-in reports.

Lead Generation Sites

For lead-gen, the most important recommended event is generate_lead. It fires when someone submits a form, or when offline lead information is recorded. Google also has a set of lead-lifecycle events that feed its lead reports:

• qualify_lead: a lead meets your rules to become qualified.
• working_lead: your team contacts the lead, or the lead contacts you.
• disqualify_lead: a lead is marked as not eligible.
• close_convert_lead: the lead becomes a customer.
• close_unconvert_lead: the lead is closed without converting.

Most of these happen in your CRM, not on your site. So they need to be sent to GA4 from your back end. For most service businesses, I start with one key event, generate_lead, with a parameter that says which form it came from. Add close_convert_lead later if you can pass CRM data back.

Other good lead-gen key events include phone number clicks on mobile, booking confirmations and quote requests. Newsletter sign-ups are worth tracking. But I’d put them in a separate, lower-value key event, not mixed in with sales enquiries.

E-Commerce Sites

The online sales events follow the shopping journey: view_item_list, view_item, add_to_cart, view_cart, begin_checkout, add_shipping_info, add_payment_info, purchase and refund, among others.

Collect all of them so the funnel and e-commerce reports work. But mark only the true outcome as a key event. For most shops that’s purchase, which is already a key event by default. Make sure it carries value and currency parameters. GA4 needs both to report revenue and to pass values to Google Ads.

Be aware of one thing. Linking Google Ads with ads personalisation turned on can mark extra events such as add_to_cart, begin_checkout and view_item as key events on their own. Check your key events list after linking and decide if you want them there.

Counting Method: Once per Event or Once per Session

Each key event has a counting method. It decides how repeats are counted. Google’s documentation on the key event counting method describes two options:

New key events default to once per event. Key events moved over from Universal Analytics goals usually default to once per session. That’s why older properties sometimes show lower numbers than expected.

To change it, go to your key events list, open the three-dot menu on the row and choose Change counting method. You need Marketer access or above. The change applies to future data only.

Here’s an example. Say a plumbing company’s quote form sometimes gets submitted twice, because people double-click or reload the confirmation page. Switching generate_lead to once per session stops those duplicates from inflating lead counts. An online shop should keep purchase on once per event, because two orders in one visit really are two orders.

Where GA4 Key Events Show Up in Reports

Once your key events are collecting, you’ll find them in several places:

• Key events report: under Reports > Engagement. It shows each key event with counts and users.
• Traffic acquisition and user acquisition: a Key events column for each channel, source or campaign. Use the dropdown above the column to pick a single key event instead of the combined total.
• Pages and landing page reports: which pages lead to key events.
• Metrics: session key event rate (sessions with at least one key event) and user key event rate (users who completed at least one).
• Advertising section: attribution paths and model comparison for key events, plus the conversion performance report for Google Ads conversions.

The single-key-event dropdown is the most underused feature here. A combined total that adds newsletter sign-ups to purchase orders means almost nothing. I always pick the specific key event I care about before I judge a channel.

Key Events and Search Console

Search Console itself doesn’t show key events. The link happens inside GA4. Once you link Search Console to your property, GA4 adds a Google organic search queries report and a Google organic search traffic report. The second one pairs landing pages with Search Console and Analytics metrics. To combine both in one view, see my guide to a free Looker Studio SEO dashboard.

That landing page view is where SEO meets outcomes. You can see which organic landing pages bring clicks and which really bring key events. If you’re already building custom views in Search Console, my guide to Search Console’s AI report builder pairs well with this. Pages that get clicks but no key events are often worth making stronger with better internal links to your service or product pages.

Key Events and Google Ads

In GA4, with a linked Google Ads account, you can create Google Ads conversions from key events. In Google Ads, those show up as conversions and can be used for bidding.

Don’t expect the numbers to match exactly. Google Ads credits conversions to its own ads and reports them against the date of the ad click. GA4 reports key events against the date they happened and credits them across every channel. Goal categories and bidding settings for those conversions are managed in Google Ads, not GA4.

Common GA4 Key Event Mistakes

Most broken GA4 setups I look at come down to a few avoidable errors.

Too Many Key Events

The 30-event limit is not a target. If you mark scrolls, video plays, outbound clicks and every button as key events, your key event total stops meaning anything. Your session key event rate looks great while sales stay flat.

Here’s the test I use: would you be happy to pay for this action through advertising? If not, it’s a normal event. Most small business sites need between two and five key events.

Duplicate Key Events

Duplicates happen when the same action is tracked twice. Common causes include:

• A form plugin sends its own event while a GTM tag sends another for the same submission.
• The GA4 tag is installed twice, for example hard-coded and through Tag Manager.
• A thank-you page created event plus a generate_lead event for the same form, both marked as key events.
• Users reloading or bookmarking the confirmation page.

Pick one source of truth for each action and remove the rest. Use once per session counting where repeats aren’t real.

Marking page_view as a Key Event

Starring page_view makes every page view a key event. Your key event count then becomes a page view count. If you want a specific page to count, create a new event from page_view with a matching condition, as shown above.

The same care applies to enhanced measurement’s form_submit event. It can fire on search boxes and newsletter forms as well as enquiry forms. So check what it really captures on your site before you rely on it. I see this one catch people out often.

Forgetting Value and Currency

Without value and currency, a purchase still counts, but revenue is missing and the value isn’t sent to Google Ads. For lead-gen, you can set a default key event value from the key events list. That gives leads an estimated worth.

How to Test GA4 Key Events With DebugView

Never trust a new key event until you’ve watched it fire. DebugView, found under Admin > Data display > DebugView, shows events from a debug device almost in real time. This is the check I never skip.

1. Turn on debug mode. The easiest way is Tag Assistant preview mode, which Google Tag Manager opens when you click Preview. On a gtag.js site you can add the debug_mode parameter to the config instead.
2. Open DebugView in GA4 and select your device if more than one shows up.
3. Complete the action yourself. Submit the form, place a test order or click the phone link.
4. Check the event stream. The seconds stream shows the last 60 seconds, and the minutes stream the last 30 minutes. Click the event to check its name and parameters, such as value, currency or the form name.
5. Look for duplicates. If the event shows up twice for one action, you’ve found a double-tracking problem.
6. Confirm in Realtime and reports. Check the Realtime report within minutes, then the key events report the next day.

When you’re done, remove debug parameters you added by hand. Setting debug_mode to false does not switch it off. It’s also worth filtering out internal and developer traffic, so test leads and orders don’t mess up your data.

Conclusion

GA4 key events are simple once you treat them as a short list of real business outcomes, not everything you can measure. Choose a few, use Google’s recommended event names, set the right counting method, and test each one in DebugView. Then read reports by single key event, not the total.

Once your key events are reliable, the next step is seeing which sources drive them, including newer ones. My guide to tracking visits from ChatGPT, Perplexity and Gemini in GA4 shows how to separate AI referrals. Then you can see if that traffic brings leads and sales. If it does, read how to write content AI assistants can quote.