Key Takeaways
- Vocabulary: Since March 2024, GA4 “conversions” have been called key events (key events). The term "conversion" is still used for Google Ads.
- Principle: A GA4 conversion is simply an existing event that you mark as important. No event, no conversion.
- Method: Choose 3 to 5 business-value actions, create or identify the event, flip the switch, and check in real time.
- Mistake No. 1: mark
page_viewor an event triggered on every visit: the conversion rate becomes unusable.
By default, Google Analytics 4 collects dozens of events: page views, scrolling, outbound clicks, downloads. But none of them tell the tool what is valuable to your company. It is the role of the conversion tracking, renamed key events in the interface. Until it is configured, your acquisition reports compare channels based on volume, never on results.
This guide replaces our three previous articles on the subject. It covers the definition, step-by-step setup, verification, and reading of reports.
Conversion, key event, goal: What are we talking about?
In GA4, everything is event : a page view, a click, a form submission, a purchase. A key event is an event that you have marked as important. Google renamed "conversions" to "key events" in March 2024 to avoid confusion with Google Ads conversions, which remain a separate entity that can be imported from GA4.
| Term | Where | What It Is |
|---|---|---|
| Event | GA4 | Any tracked interaction (page view, click, purchase, etc.) |
| Key Event (formerly "conversion") | GA4 | An event designated as a business objective |
| Conversion | Google Ads | Action used to optimize bids, often imported from a GA4 key event |
| Objective | Universal Analytics (discontinued) | Old system: Maximum of 20 targets per view, based on URLs |
Which conversions should you track? Strategy comes before technique
An SME website doesn't need twenty conversions. It needs three to five, aligned with the business model. A conversion should correspond to an action that you can link to revenue, even if only approximately.
| Site Type | Primary Conversion | Secondary conversions |
|---|---|---|
| E-commerce | purchase | add_to_cart, begin_checkout, newsletter sign-up |
| Service Website / B2B | Submitting the contact form or quote request | Click on the phone number, download a brochure, schedule an appointment |
| Local Business | Click "Directions" or call | View the schedule page, make a reservation |
| SaaS | Create an Account | Start the trial, request a demo |
Assign a monetary value to each conversion, even if it’s an estimate: a quote that results in a €2,000 contract one out of every five times is worth €400. GA4 can then calculate revenue by channel and compare it to your advertising costs.
Enable Conversion Tracking: 4 Steps
1. Check that the event exists
Open Administration > Data View > Events. If the action to be taken is already on the list (for example form_submit collected by the improved measurement method, or purchase (sent by your e-commerce platform), proceed to step 3.
2. Create the event if it doesn't exist
Two options. The first, without code: Create an event In GA4, based on a condition related to an existing event, for example page_view whose page contains “/thank-you.” The second, more reliable method: send a dedicated event via Google Tag Manager at the exact moment the action takes place (clicking the send button, confirming payment). Our guide GA4 and Google Tag Manager explains this process in detail.
3. Mark the event as a key event
Also in Events, turn on the "Mark as Key Event" switch on the relevant row. You can also enter its name directly in the tab Key Events if the event has not yet been received. It may take up to 24 hours for it to appear in the standard reports.
4. Check in real time
Perform the action yourself on the website, then open the report Real Time or the mode DebugView. The event should appear with the flag icon, which indicates a key event. Test it in incognito mode to ensure it isn't blocked by an internal traffic filter.
demande_devis, appel_telephone) and record them in a simple shared spreadsheet: name, trigger, page, creation date. This is the most useful document when a service provider changes.
Errors That Skew Conversion Tracking
- Mark an event that occurs too frequently.
page_view,scrollorsession_startWhen used as a key event, they yield a conversion rate close to 100%. Only track rare, intentional actions. - Count the acknowledgment page instead of the cover page. If the "thank you" page is accessed directly or reloaded, you'll overcount. Instead, use the event triggered by the form submission.
- Duplicate entries between GTM and the website code. If the same purchase is sent twice, it doubles your revenue in GA4. Check in DebugView to make sure that only one
purchaseper transaction. - Forget about consent. Without Compliant banner and Consent Mode v2, some conversions are never tracked, and your cross-channel comparisons are skewed.
- Do not link GA4 to Google Ads. Your key events can power automated bidding: see How to Connect GA4 to Google Ads.
View and Analyze Your Conversions
Once the key events are in place, three reports become useful:
- Traffic Acquisition (Reports > Lifecycle > Acquisition): number of key events and conversion rates by channel, source, and campaign. This is where you’ll discover that SEO drives 40% of traffic but 60% of quotes—or the other way around.
- Pages and Screens : Which pages were viewed during sessions that resulted in conversions. This is useful for identifying the content that influences the decision-making process.
- Funnel Explorations : the steps between arrival and conversion, along with the drop-off rate at each step. See Analyze a conversion funnel with GA4.
Always compare conversions to their cost. A Google Ads campaign that generates 30 quotes at €45 each and a Meta campaign that generates 50 quotes at €120 each are not equivalent, even if the second one “converts more.” The KPIs to Track in GA4 and the cost per acquisition help you make that decision.
Track off-site conversions: calls, social media, Google Business Profile
Not all conversions take place on your website. Clicks on a phone number can be tracked via an event click about the links tel:. Conversions from social media require proper UTM tagging, as explained in Track social media conversions with GA4. For your Google listing, add UTM parameters on Google Business Profile links in order to distinguish this traffic from traditional organic traffic.
How GreenRed Can Help You
Instead of juggling multiple tools, the GreenRed Traffic module brings these metrics together in a single dashboard, compares them over time, and shows you which actions to prioritize. You can try it for free—no credit card required—on the page Rates.
Frequently Asked Questions
Why aren't my conversions showing up in GA4?
There are three main reasons for most of these cases: the event hasn’t been marked as a key event yet (check the toggle under Administration > Events), the 24-hour processing period hasn’t elapsed, or the event was never sent (test in real time with DebugView). An internal traffic filter or a consent denial may also prevent you from participating in your own tests.
How many key events can you define in GA4?
A standard GA4 property supports up to 30 key events (50 for GA4 360). In practice, three to five are sufficient to manage an SME website; beyond that, the reports become unreadable and the conversion rate loses its meaning.
What is the difference between a GA4 conversion and a Google Ads conversion?
A Google Ads conversion is used to optimize bids and is tracked by the Google Ads tag or imported from GA4. A GA4 key event is used for analysis and does not affect campaigns until it is imported into Google Ads. The numbers often differ slightly because the attribution windows and models are not the same.
Should we assign a value to each conversion?
Yes, even an approximate figure. A value allows GA4 to calculate revenue by channel and compare your ad spend to the return on that investment. For a service-based website, estimate the value of a quote by multiplying the average order value by the conversion rate.