Measurement
Attribution Window
An attribution window is the period before a conversion in which a visit or an ad interaction can still receive credit for it. Google Analytics 4 calls it the key event lookback window, 90 days by default for most key events; Google Ads calls it the conversion window. A touch outside the window earns no credit.
- Industry term
By QueryRev ResearchPublished Updated6 min read
Why it matters.
In Google Analytics, the key event lookback window determines how far back in time a touchpoint is eligible for attribution credit. With a 30-day window, a key event on 30 January is credited to touchpoints from 1 to 30 January and to none before them. The window applies to all attribution models and all key event types[1].
The defaults differ by event. For acquisition key events, first_open and first_visit, the default is 30 days, and it can be switched to 7. For all other key events the default is 90 days, and 30 or 60 days can be chosen instead. A change applies going forward, and the window chosen also applies to session attribution[1].
Google Ads measures from the other side. A conversion window is the period after an ad interaction during which a conversion is recorded in Google Ads. For Search and Display campaigns the default is 30 days, and the window can be set from 1 to 90 days. A conversion that happens after the window is not recorded, and does not appear in the reports[2].
The two tools meet at the key event. When a key event becomes a conversion in Google Ads, it is shared between the two platforms[3]. Google Analytics says most conversion settings, the windows included, match by default across the two, and that it will also help identify and reconcile any discrepancies between the two[1]. One purchase can be credited under two windows if the settings drift apart.
Every window is a choice about what counts, and the choice belongs beside the figure. The ranking behind QueryRev’s study is built from rankings between 15 September and 14 October 2026. The study gives that window, with the day the list was created, so that anyone can see what the panel of sites rests on[4].
How it is measured.
Read the window in every tool that reports revenue: the key event lookback window in Google Analytics 4, the conversion window in Google Ads, and the rule in your store or CRM. Write each one beside its figures.
Compare the same orders under two windows. Take one quarter’s orders and count, for each window, the revenue of the orders that organic search touched without being the last touch. The orders are the same and the credited revenue is not. A longer window reaches further back from the sale, so the figure rises with the window.
Match the window to the buying cycle. Google Ads points to the time lag report in its attribution reports, which shows how the time between ad interactions and conversions varies, as a way to decide how long a window should be[2].
Measured by
- Window length in days
- Orders credited
- Revenue credited by window
A worked example.
Illustrative: an invented site, to show the method.
A coffee-equipment shop looks at one quarter’s 412 orders. Organic search took part in many of them without being the last touch: a buyer read a grinder guide in March and came back through a brand search in May. Under a 30-day window the shop credits $14.2k of those orders to organic search as influenced revenue. Under a 90-day window it credits $23.6k.
The orders did not change, and neither did the visits. The rule did. The shop reports each figure with its window written beside it and does not set a 30-day figure against a 90-day one. Both are influenced revenue. Neither is known revenue, and neither is added to the other.
What to do, step by step.
Read the window in each tool you report from and write it down: the key event lookback window in Google Analytics 4, the conversion window in Google Ads, and the rule in your store or CRM.
Measure your buying cycle, the days between a buyer’s earliest visit and the purchase. Google Ads’ time lag report shows it for ad interactions[2].
Set the window to cover most of the cycle, without reaching so far back that the credit is a guess.
Use one window for any comparison, between periods or between channels.
When you change a window, record the date. Google Analytics and Google Ads both apply a change going forward[1][2], so figures before and after are not like for like.
Write the window beside the figure in every report.
Mistakes to avoid.
Comparing figures from different windows. A 30-day figure and a 90-day figure are two answers to two questions. Compare like with like, or convert one to the other.
Assuming one default. Google Analytics uses 30 days for acquisition key events and 90 days for the rest[1], and Google Ads uses 30 days for Search and Display conversions unless it is customised[2]. A report that says “the default” without naming the tool says little.
Calling the jump after a change growth. A change to the window applies going forward[1]. A rise in credited revenue after a longer window is a change of rule, not a change in demand.
Choosing the window that flatters a channel. Pick the window from the buying cycle before you see the result, as you would pick any threshold. A window chosen for its answer is a way of choosing the answer.
Using a window shorter than the buying cycle. Google Ads notes that the setting suits businesses whose buying cycle does not fit the default 30-day window, and that a conversion after the window is not recorded[2]. Credit that arrives later is lost.
How QueryRev treats it.
In QueryRev every figure names its rule and its source and carries one of the four labels: known, influenced, modeled or incremental (the rules). A window is part of a rule, so write it beside the figure, as you would any other rule. It decides which revenue a page is credited with at the start of the loop, before a decision is drawn from it and an outcome is verified against it. See attribution model, assisted conversion, organic revenue attribution and the guide to SEO reporting in revenue.
Questions people ask.
What is the default attribution window in Google Analytics 4?
For most key events the key event lookback window is 90 days, and you can choose 30 or 60 days instead. For acquisition key events, first_open and first_visit, the default is 30 days and you can switch to 7. Changes apply from the day you make them.
What is the difference between an attribution window and an attribution model?
The window says which touches are eligible for credit: those inside the period before the conversion. The model says how the credit is shared among the eligible touches, for example all to the last one or spread across the path. You choose both, and both change the figures.
Does a longer attribution window mean more revenue?
It means more revenue credited to a channel, because older touches become eligible. The orders themselves do not change. A longer window moves credit around and can add to the influenced figure of a channel without adding a single sale.
Sources and citation.
Primary sources only: the search engines, the AI vendors, standards bodies and QueryRev’s own research. Each is cited in the text by its number.
Select attribution settingsGoogle Analytics Help ·
About conversion windowsGoogle Ads Help ·
Conversions vs. key events in Google AnalyticsGoogle Analytics Help ·
State of AI crawler access, October 2026QueryRev Research ·
Cite this definition
A suggested citation. Its link goes to the definition, whose anchor does not change.
QueryRev Research. “Attribution Window.” QueryRev AI glossary, 25 October 2026. https://queryrev.com/glossary/attribution-window#definition
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