Why it happens
Google dates a conversion by the click, not by the payment. A shopper clicks your ad on Monday and pays on Friday. Google Ads files that conversion under Monday. Shopify files the order under Friday. A report for one week in each tool covers different purchases, and the gap closes only when you compare a longer period that has had time to settle. Conversions can also keep arriving for days after a click, so the newest days of a Google Ads report are the least complete.
Google counts only purchases that followed a Google ad click. Shopify lists every paid order, whatever brought the shopper. Google Ads counts a purchase only when it can link it to a click on your ads inside the conversion window you set. Orders from e-mail, search results without an ad, social media and direct visits are in Shopify and not in Google Ads. A shopper who buys after the window has ended is also left out. So a lower Google Ads count is normal, and the real question is whether it is too low for the clicks you got. Enhanced conversions on Shopify add hashed customer data so Google can match more purchases to ad clicks.
The same purchase can be counted twice. A store may have a website conversion tag and a Google Analytics 4 import that both record the purchase. If both are set as Primary actions, Google Ads can count one order in two actions. This pushes Google Ads above your orders, the opposite of the usual gap. Value differs too when one action sends the order total and another sends the product total, or when taxes, shipping and discounts are treated differently.
A browser that blocks the Google tag, or a shopper who declines cookies, removes the purchase from Google Ads without removing it from Shopify.
Check it yourself
- 1Pick a period of at least two full weeks that ended a week or more ago. Use the same dates in both tools and set the same time zone. In Google Ads the time zone is part of the account settings. In Shopify it is in the store settings.
- 2In Shopify admin, open Orders, filter by the Online Store sales channel and by payment status Paid, and read the number of orders for the period. Leave out draft orders and subscription renewals.
- 3If your landing pages carry a Google click ID (gclid) in the address, count only the orders whose visit started that way. If you cannot tell, expect Google Ads to show fewer than Shopify.
- 4In Google Ads, open Goals, then Conversions, then Summary. Read the list of conversion actions for purchases. Note each action's source (website, Google Analytics 4 import or app) and whether it is Primary or Secondary. Only Primary actions count toward the Conversions column and toward bidding.
- 5If two Primary actions record the same purchase, set one of them to Secondary.
- 6Open Goals > Conversions > Summary, then the Diagnostics tab. Read any message about actions marked Misconfigured or Awaiting conversions, missing data or an action that has not recorded a conversion lately.
- 7Open your campaign report and check the Conversions and Conv. value columns, plus the conversion window in the action's settings. A short window drops late purchases.
- 8In GA4, open Reports, then Monetization, then Ecommerce purchases, and compare the purchases GA4 saw for the same period. A large difference between GA4 and Google Ads, when you import from GA4, points at attribution rather than at missing orders.
To see every sender that can reach Google Ads, start from Shopify conversion tracking.
FAQ
Should Google Ads match Shopify exactly?
No. Google Ads counts only purchases tied to its own ads, and it dates them by click. A close match is possible only by accident.
Why is my Google Ads value higher than my revenue?
Most often two actions count the same order, or an action sends a value that includes tax or shipping while Shopify's total differs. Check the actions listed under Goals and the value each sends.
How long should I wait before judging a week?
Give a week several days before you read it, because conversions are added back to the click date as they happen.
Does a lower count mean Google Ads is broken?
Not by itself. It is broken when the Diagnostics screen shows a problem or when the count falls to zero while your orders keep coming.