Close this search box.

Google Ads vs Google Analytics 4 Conversions: Which to Use?

Last Modified on May 20, 2024

Google has an arsenal of tools that digital marketers can use depending on what we are trying to achieve.

Chances are that if you’re working in online marketing, you have come across content about Google Ads (GAds) and Google Analytics 4 (GA4) if not used them.

GA4 For Beginners

Master the basics with our FREE GA4 Course for Beginners

While Google Ads lets you manage your ad campaigns on Google and its partner channels, GA4 helps you get the complete picture of what’s happening on your website.

Both platforms have their versions of conversions as you set up, but which one should you use and why? This is what we will cover in this post along with the following topics:

Let’s get started!

Conversion Tracking in Google Ads vs Google Analytics 4

Conversion tracking means tracking the key actions you want the users to take on your website/app, which can vary for different businesses and industries.

For eCommerce, these could be purchases, and for SaaS businesses, these could be subscriptions, demo requests, etc.

Conversions don’t necessarily have to be something that is only the end goal.

Sometimes actions leading to the main conversion event can also be considered a secondary or micro-conversion – add to carts, filling in shipping and/or payment info, and so on.

So, if you’re not measuring these actions, you won’t be able to measure the performance of your website and any marketing campaigns.

There are two ways you can track conversions in GAds:

  1. Directly by generating conversion label and ID
  2. Indirectly by import conversions from GA4
Conversion tracking method in Google Ads

For the first method, you have to add the code snippets to your website either directly or with a tool like Google Tag Manager using the Conversion ID and label:

Conversion tracking setup in Google Ads

If you select the second method to import conversions from GA4, you will have to link it to your GAds account first.

Importing GA4 conversions

But it can be confusing if you want to track the same conversion actions via different platforms, i.e., GAds and GA4, especially when the numbers are different.

So, why can there be these differences between these two platforms that are owned by the same company?

Differences Between Google Ads vs Google Analytics 4 Conversion Tracking

There could be several reasons why there’s a difference between the conversion data on both platforms, but let’s have a look at the major ones:

  • Attribution models – Currently, both GA4 and GAds have only Last Click and Data-Driven Attribution (DDA) models available. So, if you’re using different models in both, your conversion numbers will be different.

    For instance, if a user sees your ad, visits the site, abandons it, and comes back through organic search, then as per last-click attribution Organic Search will get the credit. But, if the user comes directly, then Paid Search will get the credit.
  • Key event window – Aka, the lookback window. This is how far a touch point is given credit for a conversion (renamed to key events in GA4). By default, it is 30 days in GAds and 30 days for acquisition key events (first_visit and first_open) in GA4, but 90 days for other key events. If you’re using different lookback windows, the numbers won’t match.

🚨Note: Conversions have been renamed in GA4 as Key events, but will still be referred to as conversions when shared/exported to GAds.

  • Different Conversion Dates – GAds give credit to conversions based on the date the ad was clicked, where whereas GA4 gives credit on the date the conversion happened. So, if a user saw an ad on 21st March and filled a form on 25th March, then GAds will record it under 21st. GA4, on the other hand, will record it under 25th. This difference in attribution dates can cause discrepancies.
  • Processing Times – In GAds, conversions are reflected quicker than GA4 which can take 24-48 hours (sometimes even 72 hours) to reflect, causing discrepancies until it’s processed.
  • Counting Method – Depending upon how you’ve selected the counting method, i.e., count every conversion or only one conversion in the same session, it can affect the data you see on both platforms. For instance, if you use count every conversion in GA4 for the event, but use count only once in GAds, the data will be quite different.
  • Refunds – If you’ve set up tracking for refunds on one platform but not another, the numbers would be different due to refunded transactions.
  • Length of Event Name – If the length of the GA4’s event name is more than 40 characters, Google won’t be able to append it with “_c” to mark it as conversion, so it won’t be counted. But, GAds would still count it.
  • Cross-device Tracking – While GAds tracking mechanism allows for cross-device tracking, GA4 can only do that if Google Signals are enabled.
  • Conversions Not Tracked in GA4 – Conversions coming from phone calls, and view-through sources are available in GAds. GA4 can only track conversions that happen on the website/app. So, these won’t be accounted for.
  • User Consent and Ad-Blockers – If a user doesn’t consent to be tracked on the website or uses ad-blocking extensions, then GA4 won’t be able to place the tracking cookie and won’t be able to record user interactions let alone conversion events. GAds can circumvent this issue as its tracking code is only fired when the conversion event happens.
  • Reporting Freshness – This isn’t the same as the processing times. It refers to how soon GAds conversion numbers are reflected in the reports (normally 3 hours). On the other hand, conversions imported from GA4 in the GAds account can take up to 9 hours to show up. This is why it’s not recommended to make any decisions on recent data.
  • Conversion Exclusions – GAds can exclude conversion data if it detects the ad clicks to be malicious, but they will still show in GA4. Moreover, if there are any test conversions by devs, CROs, etc. on the main website, they can inflate the numbers in GA4 but not GAds. Therefore, it’s recommended to have a test property to send any test data.

There could be other reasons as well, like the GA4 config tag not working, conversion tracking set up wrongly, data sampling in GA4, and the specific business situations that can cause these discrepancies.

Why Use the Google Ads Conversion Tracking?

There are a few reasons to use GAds conversion tracking that could be derived from some of the reasons that lead to data discrepancies between both platforms as discussed above. 

Here are some major reasons for you to use it:

  • Unlike GA4, GAds tracking doesn’t rely on client-side tracking, so it cannot be affected if visitors use privacy tools or any ad blockers that can stop the GA4 config tag from firing.
  • It provides rich data for modeling, so the predictions are better if you want to use automated bidding strategies.
  • Certain conversion types have their data available only in GAds, like phone calls and view-through which you won’t get with GA4.
  • You can see conversion data quicker with Google Ads vs Google Analytics 4  conversion tracking.
  • GAds tracking accounts for cross-device conversions as well, which might not work for GA4 if Google Signals is not enabled.
  • The length of the event name isn’t affected by the limit of 40 characters, as GA4 appends “_c” to mark an event as a conversion. If it can’t, then it won’t be counted (generally not a big issue if events are named properly).
  • Importing your GA4 conversions to GAds might also save you the pain of going back and forth between the two tools, as you can see it all in GAds.
  • Other limitations like the config tag not working and data sampling in GA4 don’t affect GAds conversion tracking.
  • In certain internet circles, it is also said that the GA4 conversion data undercounts conversions compared to GAds, which provides a more accurate picture.

These are some solid reasons why we should be leaning towards GAds conversions but what’s the case for GA4 conversions? We look into it in the next section.

Why Use the Google Analytics 4 Conversion Method?

Importing conversions into your Google Ads account can have some positive impacts as well. Let’s see how that can happen:

  • Using GA4 conversions can be quick and easy without doing any additional tracking setup for GAds conversions.
  • GA4 tracking provides a more holistic view of traffic sources’ performance and doesn’t look at only GAds (google/CPC) as the source.
  • GAds can use the data provided by GA4 to optimize for smart bidding.
  • You can look at conversions that are not entirely related to GAds, yet provide an overview of different engagement actions on the site or app.

When you import GA4 conversions into Google Ads, they are marked as “secondary conversions” and not used for bidding optimization, etc. So, you should mark them as “primary,” if that’s what you want to do.

This brings us to the million-dollar question (or more depending on your ad budget) – which one to use?

Choosing Between Google Ads vs Google Analytics 4 Conversions

We can get the best of both worlds by using Google Ads conversion tracking for a more accurate picture of what’s happening with the ads, as well as use that data for bidding strategies and campaign optimization.

Google Analytics 4 conversions can be imported and used as “secondary” where they are observed in the reports, but not used for campaign optimization.

This setup can take a little extra effort with the initial tracking setup; but in the end, you get data from two sources. That isn’t necessarily a bad thing as they are still separate.

The important thing is to be aware of the nuances and why there could be data differences between both Google products when it comes to making decisions about your campaigns.

You can have more flexibility whereas if one source breaks, you still have data from another (no absolute gaps) and you can see GAds data in GA4 reports and vice versa.

Now, unless you only run GAds and don’t have any conversions set up in GA4 (which isn’t recommended), then you can only use GAds conversions. However, it would be better to include web analytics as part of your digital marketing strategy.


In this post, we discussed what conversion tracking in GAds is and how GA4 conversions can be imported into Google Ads, which led us to learn some major reasons for data discrepancy between both platforms.

We then looked at how using GAds conversions can be helpful and what GA4 conversions bring to the table considering they have different purposes to serve.

Finally, we explored which option of conversion tracking would work best and landed on the recommendation to use both of them to have more data, accuracy, and flexibility.

So, if you’re looking to set up GAds conversion tracking, check out our post on Google Ads Conversion Tracking with Google Tag Manager.

What conversions do you use in your Google Ads account? How does it affect your data? Let us and our readers know in the comments!



Master Data & Analytics with MeasureMasters

Exclusive Courses & Workshops | Ongoing Troubleshooting | Support Resources, Tools & much more