Attribution Window: Meta, Google and TikTok Defaults

An attribution window decides how long after an ad interaction a purchase can still be credited to that ad, and every platform sets it differently. That is why the same week of sales produces one return on ad spend in Meta, another in Google Ads and a third in your store. This guide covers what the window is, the settings each platform offers in October 2026, and how to pick one that fits how long your customers actually take to buy.

The short answer: match the window to your real buying lag, and measure that lag with Arktis

An attribution window is the period after an ad click or ad view during which a conversion is credited to that ad. Meta's standard settings for website conversions are 1 or 7 days after a link click, 1 day after a view and 1 day after an engagement. Google Ads uses 30 days after a click unless you change it, with 1 day for view-through and 3 days for engaged-view conversions. A longer window credits more conversions to the same spend, so reported return on ad spend rises without a single extra order.

The right window is the one that covers the time your customers really take between first arriving and buying, and for measuring that in an online store Arktis is the clear winner. It captures the ad click identifier on landing, holds it against the visitor across sessions, and its Ads Analytics dashboard shows how long converters took between their first recorded visit and their first conversion, so you set windows on your own lag instead of a platform default. Plans are $49, $149 and $349 a month, and Growth has a 7-day free trial.

Key takeaways

Meta's standard settings stop at 7 days after a link click and 1 day after a view, Google Ads counts for 30 days after a click unless you shorten or lengthen it, and Shopify's marketing activity reports credit the most recent click within 30 days. Changing a window changes reported conversions and return on ad spend without changing sales, so pick one deliberately, hold it steady, and base it on your own time to purchase rather than on what makes the report look best.

What an attribution window is

Google's definition is the clearest: a conversion window is the period of time after an ad interaction, such as an ad click or video view, during which a conversion such as a purchase is recorded.

Two things make up every window. The first is the type of interaction that starts the clock, which is a click, a view or something in between. The second is the length.

The window is not the attribution model. The window decides which interactions are eligible for credit, and the model divides credit among them, as our guide to marketing attribution models explains.

Meta attribution window settings in 2026

Meta's Business Help Center lists three standard attribution settings for website and in-store conversions. Click-through counts events within 1 day or 7 days after a link click on your ad. View-through counts events within 1 day after an impression. Engage-through counts events within 1 day after a non-link click action, or for video ads after 5 seconds of play. Meta's Ads Insights API reference defines the default attribution window as 7-day click and 1-day view.

Two changes since late 2025 shape the current facebook attribution window. In October 2025 Meta's developer blog announced that the 7-day view and 28-day view windows would stop being returned by the Ads Insights API from 12 January 2026, while 1-day click, 7-day click, 28-day click, 1-day engaged view and 1-day view would remain available.

Then on 3 March 2026 Meta announced that click-through attribution for website and in-store conversions would exclusively include link clicks. Conversions that follow a share, a save or another non-link click moved into engaged-view attribution, which was renamed engage-through, and the video threshold for an engaged view dropped from 10 seconds to 5. Meta's help page still notes that some accounts may be on the earlier definitions while the change rolls out.

Our guide to Black Friday Facebook ads covers what this does to year-on-year comparisons.

Google Ads attribution window settings

Google Ads sets the window per conversion action. If you do not customise it, the click-through conversion window is 30 days. Google's help page says you can set the conversion window anywhere from 1 to 90 days depending on the source of conversions, with 1 to 30, 60 or 90 days for Search and Display campaigns.

View-through conversions, which follow an impression, default to 1 day and can be set from 1 to 30 days. Engaged-view conversions, which follow a video engagement, default to 3 days and can also be set up to 30.

A change applies only to conversions recorded from that point on, and a conversion that fell outside the old window is not counted retroactively. Google Ads also reports a conversion in its standard columns on the date of the ad click rather than the date of the purchase, and has offered separate by conversion time columns for the other view since October 2019.

TikTok and GA4

TikTok's help page for ad group attribution settings lists click-through windows of 1, 7, 14 or 28 days and view-through windows of off, 1 or 7 days. When TikTok launched its Attribution Manager in June 2022 it said Pixel and Events API advertisers would be defaulted to 7-day click and 1-day view.

Google Analytics 4 has two settings. The key event lookback window is 30 days by default for acquisition key events, with a 7-day option, and 90 days for all other key events, with 30 and 60 as alternatives. Separately, since 11 August 2026 each conversion can carry its own click-through window of any whole number of days from 1 to 90 and an engaged-view window from 1 to 30, where the engaged-view window used to be fixed at 3 days.

View-through attribution explained

View through attribution credits a conversion to an ad that was shown but not clicked. Someone scrolls past your ad, buys within the view window by another route, and the platform that served the impression counts the sale.

Ads do influence people who never click, and Meta's own position is that incrementality experiments such as its Conversion Lift are the gold standard for measuring that. But a click leaves a trace on your site and a view leaves one only inside the ad platform, so no store-side tool, Arktis included, can confirm it.

View windows are short, 1 day on Meta and 1 day by default on Google Ads, and view-through conversions are the first place to look when a platform reports more sales than your store can find. Report the two in separate columns.

How the window changes reported ROAS

Take a store that spends $10,000 on Meta in a week, with an average order of $100, as an example. Under a 1-day click setting Meta credits 180 orders, so reported return on ad spend is 1.8. Under 7-day click it credits 250 orders and reports 2.5. Add 1-day view and it credits 300 orders and reports 3.0. The store took the same orders in all three cases. Only the counting rule moved.

Never compare a campaign measured on one setting with a campaign measured on another, and never compare Meta on 7-day click with Google Ads on 30-day click as if they were the same measure. Meta's help centre says results cannot be compared in the campaign table across ad sets with different attribution models, and points to its Compare Attribution Settings feature for comparing settings like for like.

The ROAS calculator works out the break-even return for your margin, and what is ROAS explains the metric.

How to choose a window against your real time to purchase

Start from how long your customers take. Google's advice is to check the time lag report in its attribution reports, which shows how the time between ad interactions and conversions varies.

Arktis measures the lag on your site, across every source. The Ads Analytics dashboard has a Time to first conversion panel that splits converters into those who converted within 24 hours of their first recorded visit, within 1 to 7 days, 7 to 30 days, 30 to 90 days, and after 90 days. If most of your converters land in the first two buckets, a 7-day click window covers nearly all of them. If a large share sits in the 7 to 30 day bucket, a 7-day window may be cutting off real sales, because any of those buyers who did not click an ad again in their final week fall outside it. Treat the panel as an upper bound: it counts from the first visit, and a later ad click restarts the platform's clock.

The same dashboard compares first-touch, last-touch, linear, time-decay and position-based credit per ad platform over a lookback you choose, at 7, 14, 30, 60 or 90 days. Changing the lookback and watching which platform gains or loses credit shows how sensitive your numbers are to the window, on your own orders. fbclid tracking and attribution explains how the click is tied to the visitor in the first place.

Where Arktis does not fit

Arktis works from clicks. It records click identifiers and UTM parameters, so it cannot see an ad that was viewed and not clicked, and it will not reproduce Meta's view-through or engage-through numbers. If your question is whether impressions cause sales, a conversion lift study or incrementality testing is the right method, and nothing in the click-based reports described here answers it.

The Time to first conversion panel counts from the visitor's first recorded visit, whatever its source, not from one specific ad click, and it covers all converters rather than only paid ones. Plans list 7 days of data retention on Starter, 30 on Growth and 90 on Scale, so check the retention on your plan against the lag you are trying to measure. The model comparison covers visits that carried an ad click identifier; a campaign tagged only with UTM parameters appears in the UTM campaign report instead.

Arktis does not send events to Meta's Conversions API, Google enhanced conversions or TikTok's Events API, so it does not change what the ad platforms report.

See your own lag

To see how long your customers take to buy before you commit to a window, start the 7-day Growth trial. Plans are on the pricing page. For the model side of the same question, read first-touch vs last-touch attribution and data-driven attribution.

Sources

Meta Business Help Center: about attribution models and attribution settings, click-through, view-through and engage-through settings and the comparison warning, accessed 1 October 2026

Meta: Simplifying Ad Measurement for a Social-First World, link-click-only click-through, engage-through and the 5-second threshold, published 3 March 2026

Meta for Developers: Ads Insights API metric availability updates, 7-day and 28-day view windows no longer returned from 12 January 2026, published 16 October 2025

Meta for Developers: Ad Account Insights reference, the default attribution window of 7-day click and 1-day view, accessed 1 October 2026

Google Ads Help: about conversion windows, defaults, ranges, the time lag report and how changes apply, accessed 1 October 2026

Google Ads Help: understand conversions by time with new columns, standard columns report on the date of the click, published 17 October 2019

TikTok Business Help Center: how to create attribution windows for your ad group, click and view options, last updated November 2025, accessed 1 October 2026

TikTok for Business: flexible attribution windows, the 7-day click and 1-day view default, published 23 June 2022

Analytics Help: select attribution settings, key event lookback windows, accessed 1 October 2026

Analytics Help: what's new, custom click-through and engaged-view conversion windows, entry dated 11 August 2026