If you run lead generation and you cannot tell GA4 which actions actually matter, you are flying blind. This guide shows you how to set up GA4 conversions (now called Key Events) for a lead gen website, step by step, so you can measure real inquiries instead of vanity pageviews and feed clean conversion data into Google Ads.
One thing to clear up before we start. In late 2024 Google renamed "Conversions" inside GA4 to "Key Events." The action is the same. A Key Event is any event you tag as important, like a form submission or a phone click. The word "Conversion" still exists, but it now refers to the Google Ads side, specifically when a Key Event is imported into Google Ads. Keep that distinction in mind and the rest of this becomes simple.
What Counts as a Conversion for Lead Generation
Start by deciding what a lead actually is for your business. For most service businesses and B2B sites, the events worth tracking as Key Events are:
Contact form submission
Quote or demo request form submission
Phone number click (mobile)
WhatsApp or chat click
Email address click
Newsletter or gated content signup
Thank you page view (the confirmation page after a form)
Do not mark everything as a Key Event. If you tag ten different actions, GA4 and Google Ads stop knowing what success looks like, and your bidding suffers. Pick one primary lead action, usually the main contact or quote form, and treat the rest as secondary.
Step 1: Confirm GA4 Is Installed Correctly
Before you create conversions, make sure the base tracking works. Open your GA4 property, go to Reports, then Realtime. Load your website in another tab and click around. If you see your own session appear in Realtime within a few seconds, GA4 is firing.
If you see nothing, your tag is not installed or is blocked. The cleanest fix is to install GA4 through Google Tag Manager rather than pasting the gtag snippet directly, because GTM gives you control over event tracking later without touching site code. If you are not using GTM yet, that is the first gap to close.
Step 2: Make Sure the Lead Event Actually Exists
GA4 cannot mark an event as important if that event never fires. So the first real question is: does GA4 already record your lead action as an event?
GA4 captures some events automatically through Enhanced Measurement, including outbound clicks and file downloads. But form submissions are inconsistent. GA4 has an automatic form_submit event, and it works on some forms and silently fails on others, especially forms built with page builders, popups, or AJAX submissions that do not reload the page.
To check, go to Admin, then under Data display click Events. Submit a test lead on your own site, wait a minute or two, and look for an event like form_submit or generate_lead in the list. If it shows up, you can use it. If it does not, you need to create the event yourself.
Step 3: Create the Lead Event (If GA4 Is Not Capturing It)
You have two reliable options.
Option A: Track it in Google Tag Manager. This is the better approach for lead gen. In GTM, create a trigger that fires on your form success, for example a form submission trigger or a trigger that fires when the thank you page loads. Then create a GA4 Event tag that sends an event named generate_lead using that trigger. Publish the container. Test again in GA4 Realtime and confirm the generate_lead event appears.
Using the thank you page as the trigger is often the most dependable method. If a user lands on /thank-you or /quote-received, you know the form succeeded, and a simple page path trigger captures it without wrestling with form listeners.
Option B: Create an event inside GA4 from an existing signal. In Admin, go to Events, then click Create event. You can build a new event that fires when an existing event matches a condition, for example when page_view has a page_location that contains "thank-you." Name the new event generate_lead. This works entirely inside GA4 with no code, which is useful if you do not have GTM access yet.
Use a clean, standard event name like generate_lead. It is one of Google's recommended event names, which helps GA4 and Google Ads understand the action.
Step 4: Mark the Event as a Key Event
This is the actual "conversion setup" step, and it takes about ten seconds once the event exists.
In GA4, click Admin.
Under Data display, click Events.
Find your lead event in the list, for example generate_lead or form_submit.
Toggle the star icon (Mark as key event) next to it. A filled star means it is now a Key Event.
That is it. From this point forward GA4 counts that action as a Key Event and reports on it across your reports, exploration, and audiences. If you ever need to undo it, click the star again to turn it back into a regular event.
One caveat on timing. If you just created a brand new event and it has not fired yet, it may not appear in the Events list. Trigger it once with a test submission, wait a few minutes, and it will show up so you can star it.
Step 5: Import the Key Event into Google Ads as a Conversion
Measuring leads in GA4 is useful. But if you run Google Ads, the real payoff is feeding that Key Event into Ads so Smart Bidding can optimize toward leads, not clicks.
First, link the accounts. In GA4 Admin, under Product links, open Google Ads links and connect your Google Ads account. In Google Ads, confirm the link is accepted.
Then import the conversion. In Google Ads, go to Goals, then Conversions, then Summary, and click New conversion action. Choose Import, then Google Analytics 4 properties, then Web. Select your Key Event, for example generate_lead, and import it.
After importing, open the conversion action and check two settings. Set it as a Primary conversion goal if this is the lead action you want to bid toward. Confirm the attribution and counting settings make sense for lead gen, usually "one" conversion per click rather than "every," since one person filling a form twice is still one lead.
Give it 24 to 48 hours. Conversion data flows from GA4 to Google Ads on a delay, so do not panic if numbers are not instant.
Step 6: Verify Everything Before You Trust the Data
Skipping verification is how people end up optimizing against broken data for months. Do these three checks.
Check GA4 Realtime. Submit a real test lead and confirm the Key Event fires in the Realtime report under the Key Events card.
Check GA4 standard reports the next day. Go to Reports, then Engagement, then Events, and confirm your Key Event has a count that roughly matches the leads you actually received.
Check Google Ads after 48 hours. In the Conversions summary, confirm the imported action shows a status of "Recording conversions" and not "No recent conversions." If it says no recent conversions after two days of real leads, the link or the import is broken.
Common Mistakes That Break Lead Tracking
Marking too many events as Key Events. This dilutes your data and confuses automated bidding. Keep one primary lead action.
Relying on GA4 automatic form_submit. It fails silently on many forms. Test it, and if it does not fire on your form, build the event in GTM or off the thank you page.
Counting thank you page views without deduplication. If your thank you page can be refreshed or revisited, you inflate lead counts. A dedicated generate_lead event or "one per session" logic prevents this.
Forgetting DebugView. GA4 DebugView, found in Admin under Data display, lets you watch events fire in real time on your own device using the GA Debugger extension or GTM Preview. It is the fastest way to confirm an event works before you mark it as a Key Event.
Not excluding internal traffic. Your own visits and test submissions can pollute conversion data. In Admin, under Data settings, define internal traffic and filter it out so your team's testing does not count as leads.
Key Takeaways
In GA4, conversions are now called Key Events. The setup is: make sure the event fires, then mark it with the star icon under Admin, Data display, Events.
For lead gen, track the action that represents a real inquiry, usually a form submission or a thank you page load, and keep one primary Key Event.
If GA4 does not capture your form automatically, create the event in Google Tag Manager or build it in GA4 off the thank you page. Name it generate_lead.
Link GA4 to Google Ads and import the Key Event as a conversion so Smart Bidding can optimize toward leads.
Always verify in Realtime, in next day reports, and in Google Ads after 48 hours before you trust the numbers.
Getting this right is the difference between guessing and knowing which campaigns actually produce leads. If you want to build these skills properly and set up clean measurement from scratch, our GA4 course walks through conversion tracking end to end, and the Google Ads course shows you how to turn that conversion data into lower cost per lead
Sources: Love's Data on GA4 Key Events, OptimizeSmart GA4 Key Events tutorial
