The attribution window is the period after someone interacts with your ad during which Meta will credit a conversion to that ad. With 7-day click, any purchase made within a week of a link click counts. With 1-day click, only purchases within 24 hours count. The second setting reports fewer conversions and a lower ROAS than the first, from exactly the same real sales.
What changed in March 2026: Meta now counts only link clicks as click-through. Conversions after a like, share, save or other non-link click, and after an engaged video view (5 seconds or more), moved to a separate bucket called engage-through (Meta announcement, 3 March 2026). If your click-through numbers dipped in spring 2026 without a change in sales, this is usually why.
It is not a metric: it is a crediting rule. That is why comparing two periods, two accounts or two agencies without checking the window first means comparing different things.
The windows available and what each one counts
| Setting | What it counts | How it behaves |
|---|---|---|
| 1-day click-through | Conversions within 24 hours of a click on an ad link | Strictest. Closest to a last-click view |
| 7-day click-through | Conversions up to 7 days after a link click | Higher, especially with a longer buying cycle |
| 1-day engage-through | Website and in-store conversions within 24 hours of a non-link interaction (like, share, save) or a video view of 5 seconds or more | Added on top of click. Replaced "engaged-view" in March 2026 |
| 1-day view-through | Conversions within 24 hours of seeing the ad, with no interaction | The most debated. Normally combined with a click window, not used on its own |
| 7-day click + 1-day engage + 1-day view | All of the above together | Highest totals. The default for website conversion campaigns |
Treat engage-through and view-through the same way: informative, not proof. Moving from the default to "1-day click" lowers reported ROAS, and the longer your buying cycle, the bigger the drop. Sales that have already happened do not change at all; what can change is future delivery, as the next sections explain.
A worked example: same sales, three ROAS figures
An online store spends €10,000 on Meta in a month. The real purchases behind the ads are fixed. Only the window changes:
| Window | Attributed revenue | Reported ROAS |
|---|---|---|
| 1-day click | €24,000 | 2.4 |
| 7-day click | €31,000 | 3.1 |
| 7-day click + 1-day engage + 1-day view | €38,000 | 3.8 |
The figures are illustrative, but the pattern holds in any account: one budget, one set of customers, three answers to "is Meta working?". If your break-even ROAS is 3, the same month looks like a loss, a narrow win or a clear win depending on a dropdown. That is why the window has to be fixed before anyone reads the number, and why you need a check outside the platform such as MER.
Why the window matters for your decisions
- Historical comparisons break. If ad sets were rebuilt or duplicated with a different window four months ago, or someone switched the reporting view, the before-and-after you are looking at means nothing. It is the first thing we check when auditing a drop in performance.
- The algorithm optimises towards what you count. The window is not just reporting: it decides which conversions feed delivery. With 1-day click, delivery leans towards impulse buyers; with 7-day click, towards people who take their time.
- Channels stop adding up. Long and view-through windows create the most overlap with Google Ads, email and organic. The more generous the window, the further Ads Manager ROAS drifts from what the business sees.
Which window to use for your business
- Low ticket, impulse purchase (fashion, accessories, consumables): 1-day click is close to reality and avoids inflating results. At most, 7-day click without view.
- Mid to high ticket, considered purchase (electronics, furniture, courses): 7-day click. With 1-day click you cut off real conversions and the algorithm learns from far fewer signals.
- B2B or a buying cycle of weeks: no Meta window captures the cycle. Decide with the real CAC from your CRM, and use Ads Manager only to rank creatives against each other.
- View-through: use it to read, not to decide. It is useful as a secondary column to understand the effect of video and reach campaigns; making it your main metric means taking credit for sales you did not cause.
Our rule of thumb: one window, chosen deliberately and used for every new ad set for at least a quarter. Consistency is worth more than the perfect setting, because what you need is to benchmark against your own history.
How to check which window you are looking at
In Ads Manager there are two different things that are easy to confuse:
- The ad set attribution setting is the one delivery optimises for. You will find it in each ad set, under Conversion > "Attribution setting". Once an ad set is published it usually cannot be changed there, so a new window means a new or duplicated ad set.
- The reporting view only changes how the data is shown to you. "Compare attribution settings" in the columns menu puts several windows side by side for the same ads, including 28-day click, which no longer exists as an optimisation setting but is still available for reporting. Changing the view does not affect delivery, but it changes everything you report.
If ad sets with different windows live in the same account, their cost-per-result columns are not comparable. It is one of the points we review in a Meta Ads account before touching anything else, because any conclusion drawn before that check rests on sand.
Frequently asked questions
What changed in Meta attribution in March 2026?
Meta announced on 3 March 2026 that click-through attribution for website and in-store conversions would only include link clicks. Conversions after shares, saves, likes and other non-link clicks, plus engaged video views (now 5 seconds instead of 10), are reported as engage-through attribution. Billing did not change, but click-through conversions in older reports are not directly comparable with the new ones.
What is the default attribution window in Meta Ads?
For website conversion campaigns, 7-day click-through, 1-day engage-through and 1-day view-through. It is also the setting that produces the highest numbers, so check whether it is the one you are using before comparing your results with any outside benchmark.
Does changing the attribution window affect real performance?
It affects two different things. Reporting, immediately: switch the reporting view and the same past days are recalculated, so ROAS changes. And future delivery, because the algorithm optimises towards the conversions that fall inside the window. What does not change are the sales that already happened.
Is 1-day click or 7-day click better?
It depends on how long your customer takes to decide. For low-ticket impulse purchases, 1-day click is closer to reality. For considered purchases, 1-day click throws away legitimate conversions and starves the algorithm of signal, so 7-day click is the better choice.
Should I include view-through attribution?
Not as your main metric: it credits sales to people who only scrolled past the ad and who, in many cases, would have bought anyway. As a secondary column it is useful, especially for video and reach campaigns where a click is not the expected behaviour.
Why don't my Meta sales match my store's sales?
Several things add up: the attribution window, overlap with other channels, modelled conversions and differences in time zone and date logic (Meta reports conversions on the day of the ad interaction, your store on the day of the order). The way out is not to make the two dashboards match, but to guide spend using a business-level metric such as MER and use Ads Manager only to compare campaigns with each other.
Is there still a 28-day attribution window?
Not as an optimisation setting: since Apple's iOS 14 privacy changes the longest click window you can optimise for is 7 days. You can still see 28-day click conversions for reporting through Compare attribution settings. For buying cycles longer than that, measure outside the platform, with your CRM or your store's own data.
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