Why it happens
Google files a conversion under the day of the click. Google's help says the main conversion columns are calculated by the time of the ad click, not the time of the conversion. A shopper who clicks on Monday and pays on Wednesday adds a conversion to Monday. Shopify puts the order on Wednesday. The newest days in Google Ads are always waiting for buyers who have clicked and not paid.
Conversion lag makes recent days look weak. Google calls this conversion lag, or conversion delay. Its help says that because conversions are reported by query date, the latest numbers can make the cost per acquisition "look inflated and ROAS to look deflated". Spend is reported in full at once, while some of the conversions it paid for come later. Google says conversions can be reported up to 90 days after the click.
Conversions are processed before they appear. Google's page on data freshness says clicks, impressions and cost refresh about every hour. Google's page lists last click conversions with the hourly metrics in one table and gives about 3 hours in another, so count on a few hours; with other attribution models, about 15 hours. Conversions imported from Google Analytics take about 12 hours with last click and 24 hours with other models.
Conversions sent from a server wait for the click to age. Some tools send the purchase from a server instead of a browser tag. Google's help on conversion imports lists the error Click too recent: the click "occurred less than 6 hours ago, retry after 6 hours have passed". For uploaded conversions Google says processing "typically takes less than 12 hours", and up to 72 hours for conversions keyed by GBRAID or WBRAID instead of the usual click ID.
Shopify counts orders at once. Shopify lists each paid order when it is paid, from any channel. Google Ads only counts the ones it can tie to a Google ad click. The two lines meet only after the lag has passed, and even then they are not equal.
Check it yourself
- 1In Google Ads, open Campaigns and add the columns Conversions (by conv. time) and Conv. value (by conv. time). Google says these report conversions by when they happened, which helps when you compare with Shopify.
- 2Hover over a campaign in the Conversions column. Google shows conversion lag information there, and annotations on the page when the date range is affected by lag.
- 3Add the segment Conversions > Days to conversion and look at a month you trust. It shows how many days your buyers usually take after the click. That tells you how long to wait before you judge a day.
- 4Open Goals > Conversions > Summary and look at your Primary purchase action. Note its source and its attribution model. A Website action from a tag fills in faster than one imported from Google Analytics.
- 5Compare whole days that are at least two full days old. Take Shopify's paid online orders for that day and the Google Ads conversions by conv. time for the same day.
- 6If a tool sends your conversions from a server, read that tool's log for each order. For uploads, Google's offline data diagnostics page lists the errors. Click too recent on a fresh click is expected.
A delay turns into a fault when two full days later the by conv. time numbers are still far below the orders that came from Google ads, or when the action's status says it records nothing. For a status problem, read Google Ads purchase conversion inactive. For a gap that stays after the lag, read Google Ads purchases vs Shopify orders. Meta and GA4 have their own delays, covered in purchases show up days later in Meta Ads Manager or GA4.
FAQ
How long should I wait before judging a day?
One to two days for the processing to finish, longer for the lag. Your Days to conversion segment shows how long your buyers take. On a sales weekend, judge Friday on Sunday.
Should I cut bids because the last hours look bad?
Not on the lag alone. Google's own help warns that recent cost per acquisition looks inflated because some conversions have not come in. Use the lag information and the by conv. time columns before you change anything.
Why does a sale show on an earlier day in Google Ads?
Because Google Ads files it under the day of the ad click. Shopify files it under the day of payment.
Does the 6-hour wait mean the conversion is gone?
No. Google refuses a conversion for a click younger than 6 hours and takes it after that. A tool that sends from a server waits for that point on purpose, or retries.
Does switching to last click make conversions show faster?
Google lists shorter processing for last click. The attribution model also changes which clicks get credit, so do not change it only for faster reports.