Google Ads, Google Analytics and Shopify count conversions differently: on different dates, with different attribution and different counting rules, and sometimes twice. Here's why the numbers differ, and which one to steer by.
Open Google Ads, Google Analytics and your Shopify admin for the same month, and you'll often get three different numbers of sales. Google Ads can show one and a half or two times as many as Shopify.
That's not necessarily an error. The three tools answer different questions. But a gap that size matters, because Google's bidding steers by what Google Ads counts. If it counts sales that never happened, it bids for more of them.
The short version
- Shopify counts orders. Google Analytics counts what happened on your site. Google Ads counts conversions it can link to an ad, and credits them to the day of the ad.
- Some of the gap is normal: different dates, attribution, conversion windows and modeled conversions.
- A big gap often means the same sale is counted twice, for example by a Shopify app tag and a Google Analytics import that are both set as primary.
- Steer by one trusted purchase action as primary, and set the rest to secondary.
The normal reasons for a gap
Different dates. Google Ads reports a conversion on the date of the ad that led to it. Analytics and Shopify use the date of the sale. A click on the 30th and a purchase on the 2nd land in different months. See Google's data discrepancies page.
Different credit. Google Ads uses data-driven attribution for most conversion actions. It can give a share of one sale to several ad clicks, and it only looks at Google Ads. Analytics weighs all your channels, so an email or a Meta ad can take the credit there.
Different windows. A Google Ads conversion window can be from 1 to 90 days. A sale that comes after the window is missing in Google Ads, but not in Shopify.
Modeled conversions. When visitors decline cookies, Google can estimate the conversions it couldn't observe. They show in the normal Conversions column. Shopify never sees them, because they're estimates, not orders.
Every or one. A conversion action can count every conversion after a click, or only one. For purchases, "every" is right. For leads, "one" usually is.
The reason that makes the gap big
The most common cause of Google Ads counting far more than Shopify is double counting: two conversion actions that both record the same purchase, and both set as primary.
It usually happens like this. The Google & YouTube app on Shopify creates its own purchase action. Later, someone imports the purchase event from Google Analytics, or adds a tag through Google Tag Manager. Now every order is counted twice, and Google's bidding sees twice the sales it should.
Other causes are a "purchase" action that fires on the thank-you page every time it's reloaded, and page views or add-to-basket steps set as primary conversions.
How to check your own account
- In Google Ads, go to Goals and open the conversions summary. Look at which actions are primary.
- If more than one primary action records purchases, you're probably counting twice.
- Compare one week of the Conversions column with Shopify's orders for the same week. Use the "Conversions (by conv. time)" column, which uses the date of the sale, so the dates match.
- A gap of a few percent is normal. A gap of 50% or more needs fixing.
Which number to steer by
Keep one trusted purchase action as primary and set the others to secondary. A secondary action is still recorded, but it usually no longer steers bidding. See Primary vs. secondary conversions for how to set it up.
For your own decisions, such as whether a campaign pays off, compare Google Ads with your real orders now and then. Google Ads is what the bidding sees. Shopify is what you got paid for.
How Bavian handles it
Every day, Bavian checks whether your conversion tracking can be trusted. It looks for problems such as one sale counted twice or a page view set as a primary conversion, and holds back bidding changes that depend on the tracking until it's fixed.
