Shopify glossaryGlossary4 min read
What Is an Attribution Window? Meta, Google Ads and GA4 Explained
An attribution window is how long after a click or view a sale can still be credited to an ad. Here are the defaults on Meta, Google Ads and GA4, and why your platforms report more sales than Shopify.
Key takeaways
- An attribution window is the number of days after an ad click or view during which a purchase can still be credited to that ad.
- Google Ads defaults to a 30-day click-through window and a 1-day view-through window on Search and Display. GA4 defaults to 90 days for most key events.
- Meta's API documents 7-day click and 1-day view as the default when reading results.
- Because each platform uses its own window, the same Shopify order can be claimed by more than one, which inflates combined ROAS.
- Who it is for
- Stores comparing ad reports with Shopify
- Time needed
- 4 minutes to read
- What you need
- Access to your ad and GA4 settings
An attribution window is the period after someone clicks or views an ad during which a purchase can still be credited to that ad. With a 7-day click window, an order placed 5 days after a click counts toward the ad, and an order placed 9 days later doesn't.
Google Ads calls it a conversion window, GA4 calls it a lookback window, and Meta calls it an attribution setting or window. The idea is the same. The length decides how many sales each platform claims, which shapes every ROAS and CPA you read. I don't run ad accounts, but I see the confusion this causes when store owners compare ad dashboards with their Shopify sales. Settings were checked on Google, Meta and Shopify's documentation on 7 November 2026.
How an attribution window works
- Click-through window: the days after a click during which a purchase is credited.
- View-through window: the days after someone saw the ad without clicking.
- Engaged-view window: for video, the days after someone watched a meaningful part of the ad.
Conversions that happen after the window closes aren't recorded against the ad. A longer window credits more sales to ads. A shorter one credits fewer. Neither changes how many orders you actually got.
Default windows by platform
| Platform | Default | Options |
|---|---|---|
| Google Ads | 30-day click, 1-day view | 1 to 90 days by source |
| Meta | 7-day click, 1-day view | 1, 7 or 28 days |
| GA4 | 90 days for most key events | 30, 60 or 90 days |
| Shopify reports | Last non-direct click model | 5 attribution models |
Google's engaged-view window defaults to 3 days. In GA4, acquisition key events such as first visit default to 30 days, with 7 days as the alternative. Meta's API also lists a 1-day engaged-view window. Shopify's marketing reports don't publish a window. They assign credit by model: last non-direct click by default, with last click, first click, any click and linear available.
A worked example
This example is illustrative. A shopper clicks a Meta ad on day 1, clicks a Google Shopping ad on day 4, and buys a $80 order on day 6.
- Meta: the purchase is within 7 days of the click, so Meta reports one $80 purchase.
- Google Ads: the purchase is within 30 days of the click, so Google also reports one $80 conversion.
- Shopify: under last non-direct click, the order is credited to Google only.
One real order, $160 of reported revenue across the two ad platforms. Add a few hundred orders like this and the platform dashboards can promise far more than your bank account shows.
Where to check or change the window
- Google Ads: each conversion action has its own click-through, engaged-view and view-through window in its settings.
- GA4: the attribution settings in Admin hold the lookback windows, which also apply to session attribution.
- Meta: the attribution setting is chosen per ad set, and reports can be read with different windows.
- Shopify: in
Analytics > Reports > Performance by marketing channel, use the Attribution menu to compare models side by side.
Common misconceptions
- Adding up platform conversions. Overlapping windows mean the sum is almost always higher than your real orders.
- Changing windows to fix results. A longer window makes a campaign look better without selling anything extra.
- Comparing reports with different windows. A 7-day click ROAS and a 30-day click ROAS are different measurements.
- Treating view-through sales as proof. Some of those buyers would have ordered anyway.
Related terms
- MER: total revenue ÷ total marketing spend, which ignores attribution windows entirely.
- CPA: cost per conversion, which changes with the window you use.
- Attribution model, conversion window and lookback window.
What to do next
- Write down the window each platform uses so you compare like with like. My guide to tracking ad performance in GA4 helps you build one view.
- Improve the data you send. Setting up the Meta Conversions API on Shopify makes Meta's numbers more complete.
- Make each visit count. My Shopify CRO service starts from $500, and it begins with a free store review.
Free tools
Check your own store
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Frequently asked questions
What is an attribution window?
It is the number of days after someone clicks or views an ad during which a purchase can still be credited to that ad. Purchases after the window closes aren't counted for the ad.
What is the default Meta attribution window?
Meta's Marketing API documentation lists 7-day click and 1-day view as the default when reading results. Advertisers can choose other windows, such as 1-day click, in the ad set's attribution setting.
What is the default conversion window in Google Ads?
For Search and Display, Google Ads defaults to 30 days for click-through conversions, 3 days for engaged-view and 1 day for view-through. You can change the window for each conversion action.
What is the GA4 lookback window?
GA4 defaults to 90 days for most key events, with 30 or 60 days as alternatives. Acquisition key events such as first visit default to 30 days, with 7 days as the alternative.
Why do Meta and Google report more sales than Shopify?
Each platform credits any purchase that falls inside its own window after an ad interaction, so one order can be claimed by both. Shopify counts the order once and assigns it with a single attribution model.
Sources
- About conversion windows, Google Ads Help
- Select attribution settings, Google Analytics Help
- Ad Account, Insights, Meta for Developers
- Marketing reports, Shopify Help Center
Related services and work
I'm a Shopify developer and CRO specialist. I have built and improved Shopify stores since 2018, completed more than 1,000 projects, and hold a 4.96 average rating across 719 client reviews.
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