GA4 Key Events vs Conversions: What Actually Changed

GA4 Key Events: The Rename That Broke Half the Setups I Audit

Last quarter a D2C skincare brand asked me to figure out why their Google Ads performance had cratered. CPA doubled over six weeks, ROAS fell below 1, and the media buyer was blaming creative fatigue. I opened GA4 and found the real problem in under five minutes: zero key events recorded for the past 45 days.

What happened was simple. Google had rolled out the conversions-to-key-events rename. The team's GA4 property updated. Their Google Ads link was intact, but the conversion actions in Google Ads showed "No recent conversions." Nobody noticed because the GA4 interface had reshuffled, the old Conversions report was gone, and the new report lived in a different place. Smart Bidding spent six weeks optimizing toward nothing.

This is not a rare scenario. In roughly half the GA4 properties I run a tracking audit on, the rename introduced at least one silent failure -- a broken import, a miscounted event, or a report that no longer shows what the team expects. The fix is always straightforward. The cost of not fixing it compounds every day bidding runs on bad data.

What Are Key Events in GA4

In March 2024, Google renamed "conversions" to "key events" inside GA4. The reason was specific: Google wanted to separate the analytics concept (an important event you want to track in GA4) from the advertising concept (a conversion action that feeds Google Ads bidding).

Before the rename, marking an event as a "conversion" in GA4 simultaneously made it visible in GA4 reports and available for import into Google Ads. The terminology implied these were the same thing. They are not. GA4 uses its own attribution model scoped across all traffic sources. Google Ads uses a separate model scoped to Google Ads clicks and impressions. Same event, different attribution, different numbers. I covered this gap in detail in GA4 vs Google Ads Conversions: Why They Don't Match.

The new terminology tries to make the distinction clearer:

Term	Where it lives	What it does
Key event	GA4	An event marked as important for GA4 reporting and analysis
Conversion	Google Ads	A conversion action used for bidding, reporting, and optimization in Google Ads

The underlying data pipeline did not change. Events still flow from your site to GA4, and flagged events can still be imported into Google Ads as conversion actions. What changed is the labeling and -- critically -- the UI location of the reports and settings.

Key Events vs Conversions in GA4: The Practical Differences

The rename was not purely cosmetic. Several things shifted that affect day-to-day work.

Reporting location

The old Conversions report under Life cycle is gone. Key events now appear in Reports > Life cycle > Engagement > Key events. If your team bookmarked the old report or built Looker Studio dashboards pointing to the "Conversions" metric, those references broke silently. The API metric name also changed -- conversions is now keyEvents in the Data API v1.

Counting in GA4 vs Google Ads

GA4 counts these actions on the date the event occurred. Google Ads counts conversions on the date of the ad click that led to the event. For a business with a seven-day consideration cycle, these dates will frequently disagree. This is not new behavior, but the rename makes the divergence more visible because the terms are now explicitly different.

Attribution settings

GA4 attribution settings apply only to flagged events in your property. When you import one into Google Ads, the platform applies its own data-driven attribution model, ignoring whatever you configured in GA4. This means your GA4 report and your Google Ads conversion report will almost never match, even when they reference the same underlying event. For a deeper explanation of how attribution models create these gaps, see Marketing Attribution Models Explained.

How to Set Key Events in GA4

Setting them up is mechanically simple. The mistakes happen in the details around counting, value assignment, and the Google Ads handoff.

Step 1: Identify the events that matter

Write down the two or three events that represent real business outcomes. For ecommerce: purchase. For lead gen: generate_lead or a custom event like demo_request. For SaaS: sign_up or trial_start.

Do not mark engagement signals like scroll, file_download, or newsletter_signup as key events unless they directly correlate with revenue. Every one you import into Google Ads becomes a signal Smart Bidding optimizes toward. Flag ten and the algorithm chases the cheapest one -- usually a scroll. Also keep in mind that GA4 enforces a hard limit of 30 key events per property. That ceiling sounds generous, but it fills up fast when multiple teams mark events without coordination -- so plan your designations deliberately.

Step 2: Mark the event as a key event

In GA4, navigate to Admin > Events. Find the event and toggle "Mark as key event." If the event does not exist yet, you need to create it first. I walk through event creation, naming conventions, and the parameter pitfalls in GA4 Events: Parameters, Custom Events & Common Mistakes.

Two counting options matter here:

Counting method	Use case
Once per session	Lead gen -- one form submission per session equals one marked event
Once per event	Ecommerce -- each purchase event counts separately, even within the same session

The default is "Once per event." For lead-gen forms, switch to "Once per session" to avoid inflating numbers when a user double-submits or refreshes the confirmation page.

Step 3: Add value and currency

Every flagged event should carry a value and currency parameter. For ecommerce, your data layer should already push these with the purchase event. For lead gen, assign a static value: average deal size multiplied by your close rate. A demo request worth EUR 12,000 at a 15 percent close rate is EUR 1,800 per conversion action.

Without value and currency, GA4 records the event but reports zero revenue. Worse, if you later enable value-based bidding in Google Ads, the imported conversion action has no value to optimize against.

Step 4: Import into Google Ads (if needed)

If you use Google Ads, go to Goals > Conversions > Summary in Google Ads and import the GA4 key event. It becomes a Google Ads conversion action with its own attribution window and counting method. Be careful not to create a duplicate -- if you already have a native Google Ads conversion tag firing on the same action, importing from GA4 will double-count. I see this in roughly one in three accounts. The GA4 import trap post covers the decision framework.

Step 5: Verify

Use Tag Assistant to walk through the conversion flow. Confirm the event fires once with the correct parameters. Check GA4 Real-Time reports to confirm the designation is active. If you imported into Google Ads, verify the conversion action shows "Recording conversions" within 24 hours.

Events vs Key Events in GA4: When to Mark and When Not To

Not every event deserves this designation. GA4 collects dozens of events automatically -- page_view, session_start, first_visit, scroll, and more. Enhanced measurement adds file_download, video_start, and outbound clicks. These are useful for analysis. They do not warrant the designation.

The rule I apply: if the event does not directly represent revenue or a step that reliably leads to revenue, it stays a regular event. The designation should be scarce. Two to four per property is typical for a clean setup. Mark too many and your reports become noise, your Google Ads imports become polluted, and your bidding becomes unfocused.

If you are unsure which events to track in the first place, start with the GA4 recommended events guide. Recommended events like purchase and generate_lead are designed to feed GA4's built-in reports. They are the natural candidates for this label.

The GA4 Key Events Report: Where to Find Your Data

After the rename, the report moved. Here is where to find it:

• Standard reports: Go to Reports > Life cycle > Engagement > Key events. This shows counts by event name with breakdowns by source/medium.
• Explorations: Use the keyEvents metric in Free Form or Funnel explorations. If you previously used conversions in saved explorations, update the metric reference.
• GA4 attribution settings: Under Admin > Attribution settings, choose your reporting attribution model (data-driven or last click) and the lookback window. These settings control how GA4 distributes credit across touchpoints in the report. They do not affect Google Ads.

One detail that catches teams off guard: the report shows data only from the date you marked the event. It does not backfill. If you marked purchase as a key event on June 1, reporting starts on June 1, even though purchase events existed before that date. The raw event data still lives in your property -- you can see it in Explorations or in the BigQuery export -- but the dedicated report itself has no history prior to the toggle date.

Common Failures After the Rename

I have audited dozens of GA4 properties since the rename. These are the failures that keep appearing.

Broken Looker Studio dashboards. Teams that built dashboards using the old "Conversions" metric found their charts empty after the rename. The fix is updating the metric reference to the new name in the GA4 connector.

Unmarked events. The rename reset some configurations. I have seen properties where previously marked conversions reverted to regular events. Always verify under Admin > Events that the toggle is active.

Duplicate counting in Google Ads. Teams that had both a GA4 imported conversion and a native Google Ads tag sometimes created a second import after the rename, thinking the old one was deprecated. Now they have three conversion actions for the same event. Check Goals > Conversions > Summary in Google Ads and deduplicate.

Consent gaps. If your consent banner blocks GA4 from loading for non-consented users, your tracked actions undercount. Consent Mode v2 with behavioral modeling can partially recover this signal, but only if implemented correctly. Without it, Safari users on a seven-day ITP cookie cap plus consent denial can vanish entirely from your data.

If any of this sounds familiar and you are not sure what your property is actually tracking, a structured audit is the fastest way to find out. I review event configuration, import integrity, consent implementation, and attribution settings in a single pass.

FAQ

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