What's the Attribution Window for Instacart Ads in 2026?

Instacart Ads use a 14-day attribution window in 2026: a purchase is credited to an ad if the shopper buys the product within 14 days of clicking it. This window applies consistently across Instacart's main ad formats, including Sponsored Product campaigns, Featured Product campaigns, and display ads.

Multi-Touch Attribution Is Now the Default Model

Alongside the 14-day window, Instacart now defaults to a linear multi-touch attribution model rather than a last-touch model. Linear multi-touch distributes credit for a sale across every ad a shopper interacted with in the lead-up to purchase, instead of giving 100% of the credit to the last ad clicked. Instacart still offers an improved last-touch model as an alternative for advertisers who prefer it, but multi-touch is what a new account sees by default, and switching between the two models changes which specific placement gets credited for a given sale even though the underlying 14-day window stays the same.

Why Multi-Touch Matters More on a Grocery Platform

Grocery shopping trips on Instacart routinely involve a shopper seeing and interacting with several sponsored placements in a single session — a Featured Product banner, then a Sponsored Product result further down the search page. A last-touch model would give full credit to whichever ad happened to be clicked last, understating the contribution of earlier touchpoints in the same basket-building session. Multi-touch attribution is Instacart's answer to that specific dynamic, and it changes how advertisers should read which placement is "working" versus just capturing credit late in the funnel.

How This Compares to Other Retail Media Attribution Windows

Instacart's 14-day window matches Walmart Connect's own 14-day default for Sponsored Products, which makes side-by-side ROAS comparisons between the two retail media networks reasonably consistent without extra adjustment. That consistency doesn't extend to every retailer, though — some retail media networks vary their default window by ad format, so a 14-day figure on one platform shouldn't automatically be assumed to match a same-named format on another without checking both the window length and the attribution model behind it.

What to Check Before Trusting a Cross-Platform ROAS Comparison

Two numbers labeled "14-day ROAS" from different platforms are only genuinely comparable if both the window length and the underlying attribution model match. A Walmart Connect report on last-touch attribution and an Instacart report on linear multi-touch attribution, even with identical 14-day windows, will distribute credit differently across a shopper's path — so matching the window alone isn't sufficient to call the two numbers equivalent.

Bottom Line

When comparing Instacart Ads performance against another retail media network, confirm both the attribution window length and the attribution model (multi-touch versus last-touch) — matching the window alone isn't enough if one platform is crediting the whole basket-building session and the other is crediting only the final click. That single check prevents the most common source of retail-media budget decisions being made on numbers that were never actually comparable in the first place.

Sources: Instacart Ads documentation (docs.instacart.com), "Linear attribution reporting" and "Measuring display ad performance"; Perpetua Help Center, "Instacart Ads Attribution Window."