GA4 Conversion Tracking: How to Set It Up Right

GA4 conversion tracking comes down to three moves: send the action you care about to GA4 as an event, mark that event as a key event, then test that it fires once and only once. Google now calls what used to be a GA4 conversion a key event, so if you can't find a 'conversions' toggle, that's why. This guide walks through each move in plain language, for business owners who want to know which leads are coming from their website and which ones aren't.

We're a marketing agency in London, Ontario, and we work with businesses across multiple industries, not one niche. The most common GA4 problem we see is not a missing tool. It's a site that tracks 40 things, trusts none of them and can't say how many real enquiries came in last month.

TL;DR

• A key event is any GA4 event you mark as important to your business, such as a quote request, a booked call or a purchase.
• Track few actions, and only ones you'd care about if they rose by 20%. Page scrolls and button clicks rarely qualify.
• Mark an existing event with the star in Admin > Data display > Events, or create a new one from a confirmation page URL without touching code.
• Never run the same event through both enhanced measurement and Google Tag Manager: you'll double count.
• Test in Realtime, DebugView and Tag Assistant before you trust a single number.

Table of Contents

• What a key event is (and why 'conversion' changed meaning)
• Decide what to track before you touch GA4
• Set up a key event in GA4, step by step
• Enhanced measurement, Google Tag Manager or custom events?
• Track forms, phone clicks and purchases accurately
• Test before you trust the numbers
• Where to read your results
• Privacy and consent for Canadian sites
• Our perspective
• Want it done for you?
• FAQ
• Sources

What a key event is (and why 'conversion' changed meaning)

Google defines a key event as an event that measures an action particularly important to the success of your business. Any event you collect can become one. Once you mark it, GA4 shows you how many users performed the action and which channels led them there.

The word 'conversion' now has a narrower job. Per Google, a conversion is an important action used to measure ad campaigns and optimize bidding, while a key event measures what matters to the business. The practical rule:

• If an action matters to your business, mark it as a key event in GA4.
• If it also matters for optimizing ads, create a conversion in Google Ads from that GA4 key event.

When key events are shared with Google Ads, they count as conversions there. That link is why clean tracking matters before you spend on ads. If you're running or planning Google Ads, our Google Ads management service leans on exactly this data.

Decide what to track before you touch GA4

This is where most setups go wrong. Owners mark everything, the numbers look impressive, and none of it connects to revenue. We'd rather you track three things well than thirty badly.

A simple test: if this number went up 20% next month, would you care? If not, it probably isn't a key event.

Here's how we sort actions for a typical service business:

For a contractor in Kitchener or Brantford, that might be three key events: contact form submitted, phone number tapped on mobile, and estimate booked. For an online shop it's mostly purchase. For a professional services firm in Toronto it might be consultation request and phone click.

Write the list down with one line each: what the action is, where it happens on the site, and what it's worth to you. If you can't say what a lead is worth, start there. Our piece on ROAS vs ROI helps you put a number on it.

Track calls, not just clicks

For many local businesses, the phone is the real conversion. A tap on a phone number is a useful signal in GA4, but it doesn't tell you whether the call was answered, booked or lost. Reviewing call insights and reporting alongside your GA4 numbers gives you a fuller picture of which calls turn into work.

Set up a key event in GA4, step by step

You have two routes, depending on whether GA4 already collects the event.

Route 1: the event already exists

1. In GA4, go to Admin > Data display > Events.
2. Find the event in the Recent events tab.
3. Click the star icon next to it.

Per Google's instructions for marking key events, you need Editor access or above on the property for this route.

Route 2: create a new event from a thank-you page

This is the no-code route, and it suits most small business sites that send people to a confirmation page after a form. Google's key event tutorial uses this exact pattern:

1. Go to Admin > Data display > Events and click Create event.
2. Name it, for example generate_lead.
3. Toggle Mark as key event.
4. Choose Create without code.
5. Set the trigger event to page_view.
6. Enter the URL of your confirmation page as the condition.
7. Click Create.

Then open the Realtime report, submit a test enquiry yourself, and look for generate_lead in the Key events by Event name card. Creating a new key event needs Marketer access or above, per the same Google documentation.

Google also explains that you can create or modify events in GA4 without changing your website, for example to measure someone landing on a confirmation page.

Two things to know up front:

• It isn't retroactive. Marking an event as a key event affects reports from that point on and doesn't change historic data.
• Reports lag. Allow up to 24 hours for standard reports, while Realtime updates within minutes.

The route depends on one thing: a real confirmation page. If your form just shows a message in place and the URL never changes, the page_view approach won't work, and you'll need Google Tag Manager.

Enhanced measurement, Google Tag Manager or custom events?

Google's documentation splits events into four kinds: automatically collected, enhanced measurement, recommended and custom events. Automatically collected and enhanced measurement events need no setup beyond enabling them in the GA4 interface. Recommended events (like purchase or sign_up) and custom events need gtag.js or Google Tag Manager.

Here's how we'd choose:

• Enhanced measurement is fine for low-stakes basics like outbound clicks and file downloads. It requires no code changes, though you're responsible for making sure no personally identifiable information is collected.
• Google Tag Manager is the right tool for anything that feeds your conversion reporting: form submissions, phone taps, purchases, booking widgets.
• Custom events fill the gaps when no standard event fits your business.

Treat enhanced measurement as a starting point, not a tracking plan. And remember the golden rule of the next section: one mechanism per event.

Track forms, phone clicks and purchases accurately

Form submissions

Enhanced measurement's form detection works best on traditional HTML forms that reload the page. Many modern sites use forms built with plugins or page builders that submit in the background, so automatic detection often never fires. If your form shows a 'thanks' message without changing the URL, use Google Tag Manager.

Google's Tag Manager help describes the custom event trigger as the tool for interactions that standard methods don't handle, with form submissions where the default submit event has been overridden as the most common use.

The pattern in Tag Manager:

1. Set up a GA4 Event tag that sends the event name you want, such as generate_lead.
2. Attach a trigger that fires only on a successful submission, not on the button click.
3. Mark that event as a key event in GA4.

That last point on triggers matters. A click fires whether or not the form validated. If someone hits submit with a missing field, you've logged a lead that doesn't exist.

Google's developer documentation describes the same flow: send the event with a GA4 Event tag, then mark it as a key event.

Phone and email clicks

Use a click trigger limited to links that begin with tel: or mailto:, and send a distinct event name for each. Mark the phone one as a key event if calls are how you win work. Keep in mind it counts taps, mostly on mobile, not completed calls.

Purchases

For an online store, use the recommended purchase event with a unique transaction ID. Most e-commerce platforms can send it for you. The unique ID matters: it's what lets GA4 recognize a repeat of the same order rather than counting it twice.

Test before you trust the numbers

A tag that 'looks right' in the editor can still fail on the live site. Run these checks in order:

1. Tag Assistant and Tag Manager preview mode. Confirm the container loads, the trigger conditions are met and the tag fires on the right action.
2. GA4 DebugView. Confirm the event actually reaches the property, with the parameters you expect.
3. Realtime report. Look for your event under Key events by Event name.
4. Standard reports the next day. Allow up to 24 hours before you judge them.

Think of it as a chain: trigger, tag, request, GA4, parameters, report. When something's missing, one link is broken, and finding which link is faster than rebuilding everything.

Duplicate events: the silent problem

Duplicates inflate your conversion count and GA4 won't warn you. The usual suspects:

• GA4 installed twice, once hardcoded on the page and once through Tag Manager.
• Enhanced measurement and Tag Manager both tracking the same interaction, which can double conversion counts without any warning.
• Overlapping triggers, or a form event firing on both the click and the successful submit.

A quick check for double installation: open Chrome DevTools, go to the Network tab, filter by collect, reload your confirmation page and count the requests to google-analytics.com. Two requests within milliseconds means two GA4 instances are running. The fix is to remove the hardcoded snippet so Tag Manager is the only thing deploying the tag.

The decision rule that keeps you out of trouble:

• If Tag Manager tracks an event, turn off enhanced measurement for that event type.
• If you have no Tag Manager tracking, leave enhanced measurement on as a baseline.
• If you need more detail than enhanced measurement gives, switch it off for that event and build it in Tag Manager.

Where to read your results

Once key events are flowing, you'll see a Key events column in many standard reports, including Landing pages and User acquisition. Per Google's documentation on key events, Explorations can use key events and session key event rate, and attribution reports show credit across touchpoints.

How we read them:

• Start with the landing page report. Which pages bring people who go on to enquire? That tells you where to invest.
• Compare channels by key events, not visits. A channel with a third of the traffic and twice the enquiries is your better channel.
• Watch the trend, not a single day. Small local sites have small numbers, and a week of data can swing wildly.
• Cross-check against reality. Compare GA4's lead count with the enquiries in your inbox and phone log. If they're far apart, the setup has a problem.

Privacy and consent for Canadian sites

Analytics is not exempt from privacy rules. Keep your privacy policy current: say that you use Google Analytics, what it collects, why, and how visitors can opt out. Don't send names, emails or phone numbers into GA4 event parameters. Google itself requires that enhanced measurement not collect personally identifiable information.

Rules also vary by province, and Quebec is generally stricter than the rest of Canada. If you target Quebec visitors, or you run advertising features and retargeting, get advice from a privacy lawyer before you finalize your consent banner. We're marketers, not your legal counsel, and this is a spot where a professional opinion is worth the fee.

Our perspective

We've seen the same pattern across industries: a business pays for a website, pays for ads, and then can't answer one question. Which of those dollars produced a phone call?

That's why we treat tracking as part of the build, not an afterthought. A site that looks good but never reports a lead is a site that never rings the phone, and you wouldn't know. Before we spend a client's ad budget, we want the key events defined, tested and tied to what a lead is worth to that business.

Our advice is simple. Track fewer things. Name them clearly. Test them on the live site. And when your ads, your SEO and your website all feed the same handful of key events, you finally get to compare them honestly. That is how you decide where the next dollar goes.

Launch & Found

Want it done for you?

If you'd rather spend your week running your business than debugging tags, we can help. Launch & Found is a marketing agency in London, Ontario. We cover advertising, website design, SEO and media production, and we work with businesses across multiple industries, not only one type. We also serve businesses in the surrounding Ontario service areas, from Kitchener-Waterloo to Sarnia and Hamilton.

Pricing is by custom quote after we assess fit, because scope depends on your site, your goals and what you already have in place. Contact us for a quote and we'll tell you honestly whether we're the right fit. You can also look at how we approach website design and build and SEO, both of which depend on solid conversion data.

FAQ

Did GA4 conversions get renamed?

Yes. In GA4, the actions you mark as important are now called key events. The term 'conversion' is used for actions in Google Ads that measure campaign performance and bidding. You can create a Google Ads conversion from a GA4 key event when an action matters for your ads.

How long until a key event shows up in my reports?

Realtime reports update a few minutes after someone triggers the event. Standard reports can take up to 24 hours. Marking an event as a key event only affects data from that moment forward, so earlier activity isn't backfilled.

Do I need Google Tag Manager to track conversions?

Not always. If your form sends people to a confirmation page, you can create a key event in GA4 from that page's URL with no code. If your form submits in the background, or you want to track phone taps and buttons accurately, Tag Manager is the better route.

Why are my conversion numbers double what I expect?

The usual cause is two things tracking the same action: GA4 installed both on the page and through Tag Manager, or enhanced measurement overlapping a Tag Manager tag. Check the Network tab for two requests on your confirmation page, and turn off enhanced measurement for any event Tag Manager already covers.

What should a small local business track first?

Start with the action that makes you money: a submitted quote request, a booked appointment or a purchase. Add phone taps if calls are a big part of your leads. Leave scrolls, video plays and generic clicks until the core events are tested and trusted.

Sources

• About key events, Analytics Help
• Conversions vs. key events in Google Analytics
• Mark events as key events, Analytics Help
• Tutorial: Set up a key event, Analytics Help
• Create or modify key events, Analytics Help
• Set up events, Google for Developers
• Enhanced measurement events, Analytics Help
• Measure conversions and key events, Tag Platform
• Custom event trigger, Tag Manager Help
• How to Track Form Submissions in GA4
• GA4 Enhanced Measurement: What to Disable
• About key events (reports and explorations)
• Call insights and reporting

Recommended

• ROAS vs ROI: What Each Tells You and Which to Track
• What a lead is actually worth to your business
• Real Estate Retargeting Ads: What They Are and How They Work
• Lead Generation Landing Pages: What Actually Works