Google Ads conversion tracking: GA4 import or the Google Ads tag — which to choose

Google Ads spends your budget based on the conversions your website reports. The path those conversions take into Google Ads determines which numbers you see and how quickly the bidding algorithm reacts. There are two paths: import an event from Google Analytics 4, or install a separate Google Ads conversion tag. Both work, but not in the same way.

We write from practice: we recently sorted out tracking for a WordPress website with a booking plugin and card payments.

Path 1: importing a GA4 event

GA4 already counts purchases — that is the purchase event. You mark it as a key event, link GA4 to your Google Ads account, and import it in the Google Ads conversions section.

Pros:

• one source of truth — the purchase is defined once, in GA4;
• you fix mistakes in one place;
• no extra code on the website.

Cons:

• GA4 data can lag by 24–48 hours, so Google Ads receives it later too;
• GA4 attributes the purchase with its own model across all channels, so Google Ads may see fewer conversions than its own tag would count.

The import does not work without the GA4–Google Ads link. If you cannot see GA4 events in the conversions section, check the link in GA4 admin settings first.

Path 2: a separate Google Ads conversion tag

In Google Ads you create a conversion action and get a tag with an ID (starting with AW-) and a label. It fires at the same moment as the GA4 purchase:

gtag('event', 'conversion', {
  send_to: 'AW-XXXXXXXXX/label',
  value: 45.00,
  currency: 'EUR',
  transaction_id: 'U-000123'
});

Pros:

• Google Ads gets conversions faster and counts them against its own ad clicks;
• enhanced conversions are supported directly (more on them below).

The downside is one more tag to maintain, and one more place where a purchase can fire too early or twice.

Which one to choose

• Google Ads is one of several channels, the budget is modest, GA4 is in good shape. Import the GA4 event. It is the simplest option with the fewest places to go wrong.
• Google Ads is your main paid channel. Go with the Google Ads tag plus enhanced conversions: faster, more precise data for the bidding strategy.

If in doubt, start with the GA4 import — you can add the Google Ads tag later.

You can have both, but for the same purchase only one conversion action should be Primary and the other Secondary. The bidding strategy uses primary actions. If both are primary, Google Ads sees one purchase as two and optimizes for a doubled number.

If the main action on your site is an enquiry rather than a purchase, the conversion counts only once the form has been submitted successfully, not when the button is clicked. What should happen to the enquiry next is covered in our article on website lead form automation.

Enhanced conversions

Enhanced conversions send the visitor's email or phone number along with the conversion, hashed with SHA-256. Google matches them against its signed-in users and can tie the conversion to a click even when there is no cookie. You switch the feature on in the Google Ads conversion settings; the Google tag can hash the data itself, or you can send it already hashed.

Two conditions: the data is sent only with the visitor's consent, and your privacy policy has to describe it.

transaction_id: protection against duplicates

A reloaded thank-you page, the Back button, a second tab — and the same purchase fires again. To stop it from counting twice, pass a unique order number as transaction_id in both the GA4 purchase event and the Google Ads conversion. Both systems recognize a repeat purchase with the same number as a duplicate.

And most importantly, the purchase fires only after the payment is confirmed. Booking systems often create the booking before payment, so "booking created" does not mean "paid".

gclid, gbraid, wbraid: keeping the click

When auto-tagging is on in your Google Ads account, a click identifier is added to the ad link: gclid, or in some cases on Apple devices gbraid or wbraid. The Google tag stores it in a cookie, and the conversion is later matched to the click.

The link breaks when:

• a redirect (say, from the non-www address to the www one) drops the URL parameters;
• booking or payment happens on another domain and the conversion is counted there, not after returning to your site;
• the visitor declined advertising cookies — then the identifier is not stored in a cookie.

A simple check: add ?gclid=test to your website address by hand and see whether the parameter is still in the address bar after all redirects.

Why you see nothing while testing

Logged-in admins are not counted. Google Site Kit disables Google Analytics for logged-in WordPress administrators — you will see ga-disable-… in the page source. So if you test while logged in, you will not see yourself in the GA4 real-time report. Test logged out or in an incognito window.

GA4 currency. A GA4 property's reporting currency may default to USD. Change it to EUR in the property settings; the change applies only going forward and does not recalculate past data.

The lag. Imported GA4 conversions do not show up in Google Ads immediately — the data can take 24–48 hours. An empty conversions column on day one does not mean something is broken.

One source. If both a plugin and hand-pasted code add the Google tag to your site, every purchase is sent twice. In the page source, the config line with your Measurement ID (starting with G-) must appear once.

Tracking is worth planning together with the website, not after launch — we broke down what drives a website's price in How much does a website cost. Our website service has its own page.

What to do tomorrow

1. In your Google Ads conversion list, check which actions are marked primary and whether the same purchase is counted by two actions.
2. In GA4 settings, check the currency and the link to Google Ads.
3. Logged out of WordPress, make a test purchase and check that transaction_id is being passed.

Frequently asked questions

How long does it take for conversions to appear in Google Ads?

Imported from GA4 — 24–48 hours. With the Google Ads tag it is usually faster. Do not draw conclusions in the first few days after a change.

Should GA4 and Google Ads numbers match?

No. GA4 attributes purchases across all channels and can look back up to 90 days, while the Google Ads tag counts only clicks and views of its own ads within its own conversion window. The difference is normal. Treat the paid orders in your own system as the only truth.

Do I need Google Tag Manager?

No. GTM is handy when you have many tags, but the rule is the same: each tag is added to the site by one tool. If GA4 is already installed through Site Kit, do not add it again through GTM.