What Is an Attribution Window? — Free Tool
An attribution window is how long after a click or a view a conversion still counts for the ad. Learn how click and view windows differ, why widening one raises reported performance without changing anything real, and how to compare two reports honestly.
How long after seeing or clicking an ad a conversion still gets credited to it — for example a 7-day click, 1-day view window. Widen the window and reported performance rises without anything really changing.
What it is
An attribution window is the period after somebody clicks or sees an ad during which a conversion still gets credited to it. It is written as a pair, because clicking and merely seeing are different strengths of evidence: a 7-day click, 1-day view window credits a purchase made up to a week after a click, or up to a day after an impression with no click.
How it is measured
The platform records the interaction, then watches for a conversion inside each window and assigns credit accordingly. Which means the number in the report is the output of a rule you chose, not an observation. Two things follow. Widening the window raises reported conversions immediately, because sales that were previously outside it are now inside it. And two platforms each running their own window will each credit the same sale, so summing their reports overstates what happened.
Commonly misunderstood
People read a change in attributed conversions as a change in performance, and most of the time it is a change in the rule. A campaign whose reported ROAS improved the same week the window was widened has told you nothing about the campaign. The honest habit is to print the window on the report, and to refuse to compare two periods that were measured with different ones. The second misunderstanding is subtler: a view-through conversion is not evidence that the ad caused the sale, only that the ad was served to somebody who later bought.
When it matters
It matters whenever a number is being compared: this month to last month, one platform to another, or a paid channel against an organic one that has no attribution window at all. It matters most when somebody outside the team reads the report, because the window is exactly the assumption they will not know to ask about.
Related terms
Features
- Plain definition, with click windows and view windows separated
- Why a 7-day click, 1-day view window is the common default and what it assumes
- How widening the window inflates results without anything improving
- Why two platforms reporting the same campaign disagree
- What to check before comparing this month’s report to last month’s
Frequently asked questions
What does 7-day click, 1-day view mean?
A conversion counts if it happened within seven days of somebody clicking the ad, or within one day of somebody seeing it without clicking. They are two windows, and the view window is much shorter because seeing is much weaker evidence than clicking.
Does a longer window mean better performance?
No, it means more conversions get credited to the ad. The sales are the same sales. This is the single most common way a report improves without the advertising improving, and it is why the window belongs on the report itself.
Why do two platforms report different numbers for the same campaign?
Partly because their windows differ, and partly because each one credits itself. If two platforms both use a seven-day window and a buyer saw both ads, both will count that sale, so the totals add up to more than you sold.
Which window should I use?
One that matches how long your purchase decision actually takes, and then leave it alone. A considered purchase needs a longer window than an impulse one, but the value of a window comes from keeping it fixed so that periods stay comparable.
Does the window change the actual sales?
Never. It changes which sales are attributed to which ad. This is the distinction worth holding on to: attribution is a bookkeeping rule applied after the fact, not a measurement of what caused what.
