Conversion tracking in GA4 is the difference between knowing that 4,000 people visited your site and knowing that 137 of them asked for a quote. If you have ever opened Google Analytics 4 and wondered why your “conversions” report is empty, or why your form submissions show up hours later (or never), this guide walks you through the whole process from zero: creating the event, marking it as a key event, and proving it works with DebugView before you trust a single number.
We wrote this for beginners, but with the real examples agencies get asked about every week: contact form submissions, button clicks, and phone number taps on mobile. At the end you will also find a list of the tracking mistakes that silently eat your data.
First, the vocabulary change nobody told you about
If you are following an older tutorial and cannot find the “Mark as conversion” toggle, you are not going crazy. Google renamed things:
| Old name (Universal Analytics / early GA4) | Current name in GA4 | What it actually is |
|---|---|---|
| Goal | Key event | An event you flagged as important |
| Conversion (in GA4 reports) | Key event | Same thing, new label |
| Conversion (in Google Ads) | Conversion | Still called a conversion, used for bidding |
In plain English: in GA4 you now create key events. When you import a key event into Google Ads, it becomes a conversion there. Everything else in the workflow is unchanged.
Step 1: Decide what actually counts as a conversion
Before touching any settings, write down 3 to 6 actions that matter for your business. Tracking 25 things is how reports become unusable.
- Lead generation site: contact form sent, quote request sent, phone tap, WhatsApp click, brochure download
- E-commerce: purchase, add to cart, begin checkout, newsletter signup
- SaaS: trial signup, demo booked, pricing page view with scroll, account created
Rule of thumb: if you would not change your ad budget because of it, it is not a key event. It can stay a normal event.
Step 2: Check what GA4 already tracks for free
GA4 collects a set of events automatically through Enhanced measurement. Turn it on before building anything custom.
- Go to Admin (bottom left gear icon)
- Under the Data collection and modification column, click Data streams
- Click your web stream
- Find Enhanced measurement and click the gear icon
Here is what you get without writing a line of code:
| Event name | Fires when | Useful for conversions? |
|---|---|---|
| page_view | Any page loads | Yes, for thank-you pages |
| click | An outbound link is clicked | Sometimes |
| file_download | PDF, DOC, XLS, ZIP etc. is downloaded | Yes |
| form_start / form_submit | User interacts with / submits an HTML form | Yes, but verify it, see warnings below |
| video_start / video_complete | Embedded YouTube video is played | Rarely |
| scroll | User reaches 90% of the page | No |
Important: form_submit only works on standard HTML forms. Most WordPress plugins, HubSpot forms, React apps and multi-step forms submit via AJAX and will not trigger it reliably. Never assume it works. Test it (Step 5).
Step 3: Create the event
You have three routes. Pick the one that matches your situation.
Route A: Create an event inside GA4 (no code, no GTM)
This works when an existing event already contains the information you need, typically a thank-you page view. This is the fastest method for beginners.
- Go to Admin > Events (under Data display)
- Click Create event, then Create
- Custom event name:
generate_lead(use lowercase with underscores, no spaces) - Matching conditions:
event_nameequalspage_viewpage_locationcontains/thank-you
- Leave Copy parameters from the source event checked
- Click Create
From now on, every time someone lands on a URL containing /thank-you, GA4 also records a generate_lead event.
Real example: phone taps on mobile
Phone links use the tel: protocol and GA4 does not count them as outbound clicks by default. With Google Tag Manager you can fire a custom event; without GTM, the cleanest workaround is a small gtag snippet on the link:
<a href='tel:+15551234567' onclick="gtag('event','phone_call_click',{'link_url':'tel:+15551234567'});">Call us</a>
Route B: Google Tag Manager (recommended for buttons and AJAX forms)
GTM gives you real control over button clicks, AJAX form submissions and elements that do not change the URL.
- In GTM, go to Variables > Configure and enable all Clicks and Forms built-in variables
- Turn on Preview mode and click the element you want to track
- Note a unique identifier in the data layer: Click ID, Click Classes, Click Text or Form ID
- Create a trigger: Click – All Elements, fires on Some clicks, condition
Click Classes contains cta-quote - Create a tag: Google Analytics: GA4 Event, choose your GA4 configuration/measurement ID, event name
quote_button_click - Add parameters if useful:
button_text,page_location - Attach the trigger, save, then Submit the container
Route C: Developer-pushed events (best accuracy)
For checkouts, logged-in areas and multi-step funnels, ask a developer to push a data layer event only on genuine success, after the server confirms it:
window.dataLayer = window.dataLayer || []; dataLayer.push({'event':'lead_form_success','form_name':'quote_request'}); This article covers the same ground in more depth.
Then create a Custom Event trigger in GTM listening for lead_form_success. This is the only method that guarantees you are not counting failed submissions.
Step 4: Mark the event as a key event
Creating the event is not enough. GA4 will collect it, but it will not appear in the conversion columns until you flag it.
- Go to Admin > Events
- Find your event in the list (it appears only after it has been received at least once, which can take up to 24 hours)
- Toggle Mark as key event on
Alternative if the event has not shown up yet: go to Admin > Key events, click New key event, and type the event name manually, exactly as it is sent (case sensitive). This is the trick that saves you a day of waiting.
Assigning a value to your key events
If you know a lead is worth roughly 80 EUR, send a value and currency parameter with the event. GA4 will then report revenue against your channels, and Google Ads can bid toward value instead of raw volume.
Counting method: once per event vs once per session
In Admin > Key events, click the three dots next to a key event to set the counting method:
- Once per event: every occurrence counts (default, good for purchases)
- Once per session: only the first occurrence in a session counts (good for phone taps and click-happy users)
Step 5: Verify with DebugView before you trust anything
DebugView is the single most useful screen in GA4 and most beginners never open it. It shows events in near real time, for your device only.
How to switch debug mode on
- Easiest way: install the Google Analytics Debugger Chrome extension and toggle it on
- With GTM: simply open GTM Preview mode, debug mode is enabled automatically
- With code: add
debug_mode: trueto your GA4 config parameters
How to read it
- Go to Admin > DebugView (also available under Reports in some layouts)
- Check the Debug device selector at the top right and pick your device
- Perform the action on your site: submit the form, tap the phone link, click the button
- Within a few seconds the event appears in the timeline
- Click the event bubble to expand its parameters and confirm values such as
page_location,form_id,value - A small star or flag next to the event name confirms it is registered as a key event
The verification checklist
| Check | What good looks like |
|---|---|
| Event name | Exactly as planned, lowercase, no typos |
| Fires once | One bubble per action, not three |
| Fires only on success | Nothing when the form is submitted with an error |
| Parameters present | Value, currency, page path populated |
| Key event flag | Visible in the event details panel |
After DebugView, wait 24 to 48 hours and confirm the data in Reports > Engagement > Events and Reports > Engagement > Conversions/Key events. Realtime reports are useful but incomplete.
Where to see your conversion rate in GA4
GA4 does not put conversion rate front and center, so build it yourself:
- Go to Explore and open a Free form exploration
- Dimension: Session primary channel group or Landing page
- Metrics: Sessions, Key events, Session key event rate, User key event rate
- Add a filter on Event name if you want the rate for one specific key event
You can also customize a standard report: open Reports > Acquisition > Traffic acquisition, click the pencil icon, and add the key event rate metric.
Sending GA4 key events to Google Ads
Once your key event is verified, you can import it:
- In Google Ads, go to Goals > Conversions > Summary > New conversion action
- Choose Import, then Google Analytics 4 properties and Web
- Select your key event and import it
- Decide whether it counts as Primary (used for bidding) or Secondary (observation only)
Our honest recommendation: for bidding accuracy, a native Google Ads conversion tag (via GTM, ideally with Enhanced Conversions) is usually more reliable and faster than an imported GA4 key event, because it is not subject to GA4 attribution modeling and processing delays. Use GA4 key events for analysis and channel comparison, use native Ads conversions for bidding. Just never count the same action twice as a primary conversion. It is argued more carefully on analyticsmania.com.
Common conversion tracking errors that cause missing data
1. The thank-you page is not a real page
Many form plugins show a success message without changing the URL. Your page_view based key event will never fire. Fix: use a data layer event or a GTM trigger on the success message element.
2. The event fires on click, not on success
Tracking the Submit button click counts every failed attempt: wrong email format, missing captcha, network error. Your GA4 numbers will be 20 to 40% higher than the leads in your inbox. Fix: fire on confirmed submission.
3. Duplicate tags
A GA4 tag hardcoded in the theme and a GA4 tag in GTM means every event is counted twice. Check with the Google Tag Assistant.
4. Consent mode blocking everything
If your cookie banner blocks analytics until consent, and your tag fires before consent is granted, the event is dropped. Configure Consent Mode v2 properly and check DebugView after accepting and after declining.
5. Cross-domain traffic breaking sessions
Sending users to a booking or payment subdomain without cross-domain measurement configured turns your own site into a referral source and detaches the conversion from its real channel. Configure it in Admin > Data streams > Configure tag settings > Configure your domains.
6. Filters and internal traffic
Your own team testing forms 40 times inflates results. Define internal traffic by IP and activate the Internal Traffic data filter in Admin. Set it to Active, not just Testing, once you are confident.
7. Event name typos and casing
GA4 treats Generate_Lead, generate_lead and generatelead as three separate events. Stick to lowercase snake_case and document your naming convention.
8. Hitting the key event limit
A GA4 standard property allows up to 30 key events. If you mark everything, you will run out and dilute your reporting. Keep the list short.
9. Forgetting the 24 to 48 hour delay
DebugView is instant. Standard reports are not. Do not declare the setup broken after two hours.
A recommended event naming table
| Action | Suggested event name | Best method |
|---|---|---|
| Contact form sent | generate_lead | Data layer push or thank-you page |
| Newsletter signup | sign_up | GTM click or data layer |
| Phone number tapped | phone_call_click | GTM click trigger on tel: links |
| Email link clicked | email_click | GTM click trigger on mailto: links |
| CTA button clicked | cta_click | GTM with Click Classes |
| Purchase | purchase | E-commerce data layer |
| Demo booked | book_demo | Data layer on confirmation |
Your 15 minute implementation plan
- Enable Enhanced measurement and confirm the GA4 tag fires on every page
- List your 3 to 6 real business actions
- Create the events (GA4 interface for URL based, GTM for clicks and AJAX)
- Mark them as key events in Admin > Key events
- Assign values and counting methods
- Verify each one in DebugView, once on desktop and once on mobile
- Wait 48 hours, cross-check against your CRM or inbox
- Import to Google Ads only when the numbers match reality
FAQ
When should I use conversion tracking?
From day one of any site that has a goal: selling, capturing leads, generating calls or signups. Without it, you cannot tell which channel, campaign or landing page actually produces business, and every marketing decision becomes guesswork.
How do I set up conversion tracking in GA4?
Create the event (automatically via Enhanced measurement, in the GA4 interface with Create event, or through Google Tag Manager), then go to Admin > Events or Admin > Key events and mark it as a key event. Finally, verify it in DebugView before relying on the data.
Where can I see the conversion rate in GA4?
Use the metrics Session key event rate and User key event rate. They are available in the Explore section and can be added to standard reports like Traffic acquisition by clicking the pencil edit icon. ga4.com goes into the numbers.
How do I check that conversion tracking works?
Enable debug mode (Google Analytics Debugger extension or GTM Preview), open Admin > DebugView, perform the action yourself and watch the event appear with its parameters. Then confirm 24 to 48 hours later in Reports > Engagement > Key events, and compare with the real leads or orders you received.
Why do my GA4 key events and Google Ads conversions show different numbers?
They use different attribution models, different lookback windows and different date logic. Google Ads credits the conversion to the day of the click, GA4 to the day of the conversion. A gap of 10 to 20% is normal. A gap of 80% means something is broken.
Are key events and conversions the same thing?
Inside GA4, yes: what used to be called conversions are now key events. The word conversion is reserved for Google Ads, where an imported key event becomes a conversion action used for bidding.
How many key events can I have?
Up to 30 per standard GA4 property. In practice, 3 to 8 well-chosen key events give you far more clarity than 30 noisy ones.
Final word
Good conversion tracking in GA4 is not about knowing every menu by heart. It is about a short list of meaningful actions, clean event names, events that fire only on genuine success, and a habit of opening DebugView before believing any report. Do that, and your GA4 property stops being a dashboard you ignore and becomes the reason you know where to spend your next budget.