Quick answer: An attribution window is the set period after someone clicks or views your ad during which a resulting conversion is credited back to that ad. Google Ads defaults to 30 days after a click; Meta defaults to 7 days.
An attribution window (also called a conversion window or lookback window) is a setting inside your ad platform, not a fact about your customers. It draws a line in time: a conversion that lands inside the window is counted as ad-driven, and one that lands a day outside it is counted as organic, direct or nothing at all. On a Google Ads conversion action with the default 30-day click window, a click on 1 September and a purchase on 25 September are credited to that ad. The same purchase on 5 October is not (Google Ads Help).
Most platforms run two windows side by side. The click-through window starts when someone clicks your ad. The view-through window starts when someone only sees it. They are almost always set to different lengths, because a click is a much stronger signal of influence than an impression.
Why the attribution window matters
The window decides which campaigns look like they are working, which means it decides where your next rupee goes. Widening an attribution window increases your reported conversions and ROAS without changing a single rupee of actual revenue. Narrowing it does the reverse. The sales in your bank account do not move either way.
The bigger problem is cross-platform comparison, because no two platforms use the same default. Google Ads defaults to a 30-day click-through window and a 1-day view-through window (Google Ads Help). Meta defaults to 7-day click plus 1-day view, and in January 2026 removed the 7-day-view and 28-day-view options entirely, so 1 day is now the longest view window it offers. In March 2026 Meta also redefined click-through to mean link clicks only, moving likes, shares, saves and engaged video views into a separate 1-day engage-through bucket (Jon Loomer, 2026). LinkedIn defaults to 30-day click and 7-day view (LinkedIn Help).
Put those three side by side in one report and you are not comparing performance, you are comparing measurement rules. This is a large part of why Meta, Google Ads and GA4 never agree on the same month’s numbers, and why the three of them added together usually exceed the sales your CRM recorded.
The window is also not just a reporting setting. Smart Bidding on Google and the delivery system on Meta optimise toward whatever the window counts, so changing it changes what the algorithm chases, not only what you see. And the change is never retroactive on any platform: historical data keeps the rules it was recorded under, so your before-and-after comparison is broken until you rebuild a baseline.
Click-through vs view-through vs engage-through windows
| Attribute | Click-through window | View-through window | Engage-through window (Meta) |
|---|---|---|---|
| What starts the clock | User clicks the ad link | Ad impression, no click | Non-link interaction (like, share, save, comment) or engaged video view |
| Google Ads default | 30 days | 1 day | Not offered (engaged-view applies to video) |
| Meta default | 7 days | 1 day | 1 day |
| LinkedIn default | 30 days | 7 days | Not offered |
| Strength of signal | Strongest, the user acted | Weakest, an impression is not intent | Middle, real interaction but no click |
| Use it for | All performance reporting | Awareness and video, reported separately | Meta social campaigns, checked before trusting |
Never merge click-through and view-through conversions into one headline number. A view-through conversion says only that an ad was served and a sale later happened, which is also true of every ad the person scrolled past that week.
How to set your attribution window
- Measure your actual time lag first. In Google Ads, use the attribution time lag report to see how many days pass between click and conversion. In Meta, use Compare Attribution Settings in Ads Manager to see how your conversions split across windows without touching live settings. In GA4, check the journey and path reports.
- Pick the shortest window that captures the bulk of conversions. If 90% of your sales happen within 6 days of the click, a 7-day window is honest and a 30-day window is mostly borrowing credit from other channels.
- Set it per conversion action, not per account. A newsletter signup and a ₹80,000 purchase have completely different decision cycles and should not share a window.
- Align windows across platforms as far as each one allows. You cannot match Google’s 30-day click on Meta, since Meta caps at 7 days. So compare Google at 7-day click when you are judging the two against each other, and keep the 30-day view for Google-only decisions.
- Write down the date you changed it. Changes apply going forward only. Any trend line that crosses that date is comparing two different measurement systems.
Here is what the choice actually does to a report. Take a Mumbai D2C skincare brand spending ₹2,00,000 a month on Meta with an average order value of ₹6,000 (illustrative numbers, but the pattern is one we see constantly):
- Reported on 7-day click + 1-day view: 148 purchases, ₹8,88,000 revenue, 4.44x ROAS
- Reported on 1-day click only: 92 purchases, ₹5,52,000 revenue, 2.76x ROAS
Same month, same spend, same customers, same sales. Now bring in margin: at a 30% gross margin the break-even ROAS is 1 / 0.30 = 3.33x. Under the first setting the campaign is comfortably profitable. Under the second it is losing money on every order. Neither number is a lie, and neither is the whole truth, which is exactly why the window has to be a deliberate decision recorded in writing rather than whatever the platform shipped with. See our ROAS glossary entry for the break-even maths.
Common mistakes
- Comparing platforms on their own default windows. Meta at 7-day click and Google at 30-day click are not measuring the same thing. Before you move budget between them, normalise the windows or at least state the difference on the report.
- Choosing the longest window available. A 90-day click window on Google will make almost every campaign look profitable, because three months is long enough for a customer to buy for reasons that had nothing to do with your ad. Longer windows flatter the platform, not your P&L.
- Changing the window mid-flight and reading the drop as a performance problem. Tightening from 7-day click to 1-day click can cut reported conversions sharply overnight. On Meta, a big enough drop in counted conversions can also push an ad set back into the learning phase.
- Forgetting the window feeds the bidding algorithm. Target CPA and Target ROAS optimise toward the conversions your window counts. Set a window shorter than your real sales cycle and you are training the algorithm on an incomplete picture of who actually buys.
- Reporting view-through conversions without labelling them. A campaign at 4x ROAS that turns out to be 60% view-through is not a 4x campaign. Break the number out so the client can see how much of it rests on impressions.
Frequently asked questions
What is an attribution window in digital marketing?
An attribution window is the number of days after an ad click or impression during which a conversion is credited to that ad. It is set per conversion action inside the ad platform. Conversions that happen after the window closes still happen, they just are not attributed to the ad.
What is the default attribution window in Google Ads?
New Google Ads conversion actions default to a 30-day click-through window and a 1-day view-through window. The click-through window can be set from 1 day up to 90 days depending on the conversion source, and each conversion action carries its own setting.
What is Meta’s attribution window in 2026?
Meta’s default for website conversion campaigns is 7-day click, 1-day engage-through and 1-day view. The 28-day click, 7-day view and 28-day view options are no longer available, and since January 2026 the longest view-through window Meta offers is one day.
Does changing the attribution window affect past data?
No. Attribution window changes on Google Ads, Meta, LinkedIn and GA4 apply going forward only, and historical data is not reprocessed. Record the date of any change and treat the periods either side of it as separate baselines rather than a continuous trend.
Should I use a 1-day or 7-day click attribution window?
Use 1-day click when the purchase is impulse-led, low-priced or time-limited, because it gives you a cleaner read on ads that genuinely caused the sale. Use 7-day click for considered purchases and lead generation where buyers compare options before acting. Check your actual click-to-conversion lag before deciding, rather than copying a benchmark.
How Uginix helps
Uginix sets attribution windows per conversion action based on your real click-to-purchase lag, then reports platform numbers next to your actual revenue so you can see the gap instead of arguing about it. Our analytics and attribution work covers GA4 lookback settings, server-side tracking and cross-platform reconciliation, and we document every window change with a date so your trend lines stay honest. If your Google and Meta numbers do not add up to what your accounts show, our free growth audit is built to find exactly that.
Related terms
- Attribution model: the rule that splits credit between touchpoints inside the window (last click, data-driven, and so on). The window decides who is eligible; the model decides who gets paid.
- View-through conversion: a conversion credited to an ad that was seen but never clicked, counted inside the view-through window.
- Lookback window: the analytics-side equivalent, in GA4 it defaults to 90 days for most key events and 30 days for acquisition events.
- ROAS (Return on Ad Spend): revenue divided by ad spend, and the metric most distorted by an over-generous attribution window.
- MER (Marketing Efficiency Ratio): total revenue divided by total marketing spend, a window-proof sanity check on platform-reported numbers.
For how these settings interact with automated campaign types, see our breakdown of Google Ads in 2026.
Sources: Google Ads Help, About conversion windows, Google Ads Help, View-through conversion window, Google Analytics Help, Key event lookback window, LinkedIn Marketing Solutions Help, Conversion window, Jon Loomer Digital, How Meta Ads attribution works in 2026.