How to Set Up Conversion Tracking in GA4 (Key Events), Step by Step

How to set up conversion tracking in GA4 comes down to one idea. Every conversion is an event you have marked as important. GA4 collects events; you decide which ones count.

This guide walks through it in order, from choosing the action to testing it. If you would rather have it built and verified for you, our conversion tracking service does that work.

What GA4 conversion tracking means now

Google Analytics now calls the events that matter to your business key events. Google says events that measure important actions are now called key events (Analytics Help).

A conversion is now a Google Ads term. You can create a Google Ads conversion from a GA4 key event. Google Ads conversions do not appear in standard GA4 reports (Analytics Help).

So in GA4 the job has three parts:

1. An event that records the action.
2. A key event mark on that event.
3. A test that proves it fires once per action.

Before you set up conversion tracking in GA4

• GA4 on every page. The Google tag or a GTM container must load GA4 across the whole site.
• The right access. Marking an existing event needs the Editor role or above on the property (Analytics Help).
• A short list of actions. A lead form, a phone click and a purchase are typical. A page view or a scroll is not.

Step 1: Choose the action and name its event

Pick the action that means business, then give its event a name that says what happened. Google’s recommended events help here. Its generate_lead event measures when a lead is generated, for example through a form (Google for Developers).

For a sale, use purchase. Google marks transaction_id as required on it, and currency as required whenever you send a value (same source).

Avoid vague names. A name like gtm.linkClick or form_interaction tells nobody what happened, and it cannot be reported on its own.

Step 2: Send the action to GA4 as an event

There are three ways to get the event into GA4. Use the simplest one that records the real action.

Way	Use it when	Where you set it up
Use an event GA4 already collects	The action already arrives under a clear name	GA4 Admin, Data display, Events
Create the event without code	The action loads its own page, such as a thank-you page	GA4 Admin, Events, Create event, Create without code
Send the event from Google Tag Manager	The action has no page of its own, such as an inline form message or a phone click	A Google Analytics: GA4 Event tag with a trigger on the completed action

Use an event GA4 already collects. Check Admin, Data display, Events, Recent events. If the action is there under a clear name, go straight to Step 3.

Create the event without code. GA4 can build a new event from one it already collects. Google’s own example creates an event from a page_view on a thank-you page URL (Analytics Help):

1. In Admin, under Data display, click Events, then Create event.
2. Enter the new event name, for example generate_lead.
3. Choose Create without code, pick page_view and enter the thank-you page URL.
4. Click Create.

The new event appears in the Custom events table straight away, but not in Recent events until Analytics processes it (same source).

Send the event from Google Tag Manager. Use this when the action has no page of its own. A form that shows a message instead of a thank-you page is the usual case. In a new tag, select Google Analytics: GA4 Event. Enter your measurement ID and an event name, then add a trigger (Tag Manager Help).

Set the trigger on the completed action, never on a button click. A click fires when the form fails validation, and it fires again on every repeat click.

Step 3: Mark the event as a key event

In Admin, under Data display, click Events. Find the event on the Recent events tab and click the star next to it (Analytics Help).

If you created the event yourself in Step 2, you can switch on Mark as key event while you create it instead.

Two things to know before you rely on it:

• It only counts forward. Google says marking an event affects reports from the time of creation. Older data does not change (same source).
• Reports lag. Allow up to 24 hours for standard reports; Realtime updates a few minutes after the event (same source).

Step 4: Choose how each key event counts

GA4 offers two counting methods. Once per event counts every time the event fires, and Google marks it as recommended. Once per session counts one per session and is labeled legacy (Analytics Help).

Check which one your key events use. Google sets once per session as the default for key events migrated from Universal Analytics goals. To change it, open the Key events tab, click the More icon on the row, and choose Change counting method. The change applies only from then on (same source).

Step 5: Test it before you trust it

Turn on debug mode with Tag Assistant or Tag Manager’s Preview, then complete the action yourself. DebugView, in Admin under Data display, shows the events Analytics collects from that device in real time (Analytics Help).

Check three things:

1. The event arrives once for one completed action.
2. It carries the right parameters, such as value and currency where you send them.
3. It is marked as a key event in the event’s details.

Events do not show in debug mode when privacy controls are in place, such as denied analytics consent (same source). Accept the cookie banner before you test.

Step 6: Send key events to Google Ads, or not

To bid on a GA4 key event, first link Google Ads and Analytics. Then create a conversion from it in Google Ads, under Goals (Google Ads Help).

Conversions created from the Analytics side start as secondary. You must change them in Google Ads before bidding uses them. Data can take up to 24 hours to appear (same source).

Do not import a key event that a Google Ads tag already counts for the same action. Both would count one lead. Our guide to why GA4 and Google Ads conversions don’t match explains how the two platforms count.

Mistakes we find when we audit this

The setup is short, so most faults come from what is counted, not from GA4 itself. One inherited lead account, Killian’s HVAC, showed three of them at once:

• The phone event was named gtm.linkClick. Calls could not be told apart from any other link click.
• No key events were marked. GA4 collected the data but reported no conversions.
• The form tag fired on a button click, so repeat clicks without a submission could count as leads.

We renamed the events, marked them as key events and moved the form tag to the actual submission. The full write-up is in what we found in four tracking audits.

If your numbers already look wrong, our GA4 audit checklist covers the property as a whole. For Google Ads itself, see Google Ads conversion tracking not working.

Frequently Asked Questions

How do you track conversions in Google Analytics 4?

You track conversions in Google Analytics 4 by marking the events that matter as key events. Send the action as an event, from GA4, a thank-you page rule or Google Tag Manager. Then click the star next to it in Admin, Data display, Events. Test it in DebugView before you rely on the reports.

How do you measure conversion rate in GA4?

GA4 measures conversion rate with two metrics. Session key event rate is the share of sessions in which a key event happened. User key event rate is the share of users who performed a key event. Both need at least one key event marked, so set that up first.

Sources (11)

All checked on 15 October 2026.

1. Analytics Help, Conversions vs. key events in Google Analytics
2. Analytics Help, About key events
3. Analytics Help, Mark events as key events
4. Analytics Help, Create or modify key events
5. Analytics Help, Change the counting method of key events
6. Analytics Help, Monitor events in DebugView
7. Analytics Help, Analytics dimensions and metrics
8. Google for Developers, Recommended events
9. Tag Manager Help, Set up Google Analytics events in Tag Manager
10. Google Ads Help, Create conversions from Google Analytics events in Google Ads
11. BlazeByte client audit report, named with permission: Killian’s HVAC, Conversion Tracking Audit and GTM Cleanup (25 July 2026).