Attribution Window
An attribution window is the set period of time after a user clicks or views an ad during which a resulting conversion is credited back to that ad or channel. It is also called a conversion window or lookback window. If the conversion happens inside the window, the channel gets the credit. If it happens after the window closes, the conversion goes uncredited or is assigned elsewhere.
Why the Attribution Window Matters
The attribution window decides which conversions your channels are allowed to claim. A 1-day window credits only conversions that happen within 24 hours of the click. A 30-day window credits conversions up to a month later. The same campaign can look like it drove 50 conversions or 200, depending solely on the window length.
This directly affects budget decisions. A short window undercounts channels with long consideration cycles, like B2B or high-ticket purchases, making them look unprofitable. A long window can over-credit channels and double-count conversions across platforms that each claim the same sale. Choosing the wrong window distorts return on ad spend before any other analysis begins.
Attribution Window vs Attribution Model
The attribution window and the attribution model answer different questions. The window sets the timeframe. The model sets the credit split.
- Attribution window: How long after a touch can a conversion still count? (time)
- Attribution model: How is the credit divided among the touches that qualify? (logic)
A conversion must first fall inside the attribution window to be eligible. Only then does the attribution model decide whether the first touch, last touch, or several touches share the credit. The window filters; the model allocates.
Types of Attribution Windows
Most platforms split the window into two parts based on how the user interacted with the ad.
- Click-through window: Credits a conversion when the user clicked the ad, then converted within the window. This is the stronger signal and usually has a longer default.
- View-through window: Credits a conversion when the user saw the ad but did not click, then converted within the window. This is a weaker signal and usually has a shorter default.
For example, a “7-day click, 1-day view” setting credits conversions up to 7 days after a click, but only up to 1 day after an impression with no click. View-through windows are common in display and social advertising where impressions outnumber clicks.
Platform Default Attribution Windows
Each ad platform sets its own defaults and configurable ranges. These defaults shifted after Apple’s iOS 14 App Tracking Transparency rollout in 2021, which shortened many windows.
| Platform | Default click window | Default view window | Configurable range |
|---|---|---|---|
| Google Ads | 30 days | n/a (engaged-view for video) | 1 to 90 days |
| Meta (Facebook/Instagram) | 7 days | 1 day | 1-day click, 7-day click, plus view options |
| TikTok Ads | 7 days | 1 day | up to 28-day click |
| GA4 | 90 days (acquisition: 30 days) | n/a | 30, 60, or 90 days |
Meta reduced its default from 28-day click to 7-day click after iOS 14, which is why historical Facebook reports often show more conversions than current ones for identical spend.
How to Set or Check Your Attribution Window
Each platform exposes the setting in its conversion or measurement settings.
- Google Ads: Go to Goals > Conversions, select a conversion action, and edit the Conversion window (1 to 90 days).
- Meta Ads Manager: Open a campaign, find the Attribution setting at the ad-set level, and choose the click and view window.
- GA4: Go to Admin > Attribution settings and set the Conversion lookback window to 30, 60, or 90 days.
Keep windows consistent across platforms when comparing channels, or each will count the same conversion under different rules. Accurate windows also depend on accurate source data, which starts with consistent UTM tags so every click is captured before the window even applies.
Frequently Asked Questions
What is an attribution window in simple terms?
An attribution window is the deadline for a conversion to count toward an ad. If someone clicks your ad and buys within the window, the ad gets credit. If they buy after the window closes, it does not. It is the timeframe that decides which sales a channel can claim.
What is a conversion lookback window?
A conversion lookback window is another name for an attribution window. The terms are used interchangeably across Google, Meta, and GA4. “Lookback” describes how the platform looks back in time from the conversion to find a qualifying click or view.
What is the difference between a click-through and view-through window?
A click-through window credits conversions after a user clicks the ad. A view-through window credits conversions after a user sees the ad without clicking. Click windows are usually longer because a click is a stronger intent signal than an impression.
What is the default attribution window in Google Ads?
The default click-through conversion window in Google Ads is 30 days. You can set it anywhere from 1 to 90 days per conversion action. Shorter windows suit impulse purchases; longer windows suit considered purchases with longer research cycles.
To make sure every click feeds your attribution window cleanly, tag your campaign links with the free UTM builder at linkutm.