--- title: "Attribution Window: Why the Same Period Shows Different Numbers" description: "Attribution windows produce conflicting data for identical timeframes. Learn why conversion paths, cookie lifespans, and model logic create these discrepancies." canonical: https://adsbeast.pro/blog/en/attribution-window-why-the-same-period-shows-different-numbers language: en published: 2026-09-06T06:42:53.092Z updated: 2026-09-16T11:06:51.238Z author: "ADS Beast editorial team" translations: - ar: https://adsbeast.pro/blog/ar/attribution-window-why-the-same-period-shows-different-numbers - es: https://adsbeast.pro/blog/es/ventanas-de-atribucion-por-que-las-cifras-no-cuadran - he: https://adsbeast.pro/blog/he/attribution-window-why-the-same-period-shows-different-numbers - ru: https://adsbeast.pro/blog/ru/okno-atributsii-pochemu-tsifry-v-statistike-raznye - sk: https://adsbeast.pro/blog/sk/okno-atribucie-preco-rovnake-obdobie-ukazuje-rozdielne-cisla - uk: https://adsbeast.pro/blog/uk/vikno-atributsiyi-chomu-toy-samiy-period-daye-rizni-tsifri --- # Attribution Window: Why the Same Period Shows Different Numbers An attribution window is the fixed period after a click or impression during which a conversion is credited to that ad interaction. Two reports covering the same calendar week can show wildly different conversion counts because each platform and analytics tool applies its own attribution window, and that window changes which touchpoints are even eligible for credit. The numbers are not wrong; they are answers to different questions about the same customer journey. ## In brief - An attribution window defines how long after a click or view a conversion can be credited to that ad. - Different windows (7-day click, 30-day click, 1-day view) include different subsets of conversions. - Cookie lifespans and cross-device tracking gaps make the same window behave differently across browsers. - Last-click versus data-driven models change which touchpoint receives credit, shifting numbers even within the same window. - Comparing platforms requires aligning windows and understanding what each platform counts as a conversion. ## What exactly is an attribution window An attribution window is the time span after a user interacts with an ad during which a subsequent conversion is assigned to that interaction. The interaction is usually a click or an impression (view). If the conversion happens outside that window, the platform does not credit the ad for it. Standard windows in paid social and search include 7-day click, 14-day click, 30-day click, and 1-day view. A 7-day click window means a purchase made eight days after clicking the ad gets no credit from that ad. The same purchase might appear in a 30-day click report. That alone explains why the same campaign shows different conversion totals depending on which window the report uses. The window is not a universal setting. Each ad platform has default windows, and each analytics tool has its own. Google Ads defaults to 30 days for most conversions. Meta defaults to 7 days after a click and 1 day after a view, though you can adjust it. If you export data from both platforms for the same week, you are comparing apples to oranges unless you manually align the windows. ## Why the same week produces different numbers across platforms Platforms do not share the same conversion path data. Meta sees a user who clicked a Facebook ad and converted two days later. Google Ads sees the same user who clicked a search ad five days before that purchase. Both platforms credit the conversion, but each uses its own window and its own attribution model to decide how much credit to assign. The same calendar week will show different numbers for three structural reasons. First, the windows differ by default, so each platform looks at a different slice of user behavior. Second, the platforms use different identity resolution. Meta relies on its pixel and login data; Google relies on cookies and its own signals. A user who clears cookies mid-journey disappears from one platform but not the other. Third, the attribution models differ. Last-click gives all credit to the final touchpoint. Data-driven models distribute credit across multiple touchpoints based on predicted influence. A conversion that happened 20 days after the first click might be excluded by a 7-day window but included by a 30-day window, and within that 30-day window, the credit might go entirely to the last click or be split across three ads. ## How click-based and view-based windows diverge Click-based windows start counting when a user clicks the ad. View-based windows start counting when a user merely sees the ad, without clicking. View-through conversions usually have shorter windows, often 1 day, because a view is a weaker signal than a click. Consider a user who sees a display ad, does not click, then searches for the brand two days later and buys. A 1-day view window excludes this conversion. A 7-day view window includes it. If your report uses view-through conversions and the platform's default view window is shorter than the time between impression and purchase, you will undercount the display campaign's contribution. View-through attribution also depends on whether the platform can tie the impression to the conversion. If the user is logged out or on a different device, the platform cannot connect the view to the purchase. This is why view-through numbers are often lower on platforms with weaker identity graphs. ## Where cookie lifespans interfere with the window An attribution window only works if the tracking mechanism survives from the interaction to the conversion. Browser cookie lifespans are shorter than most attribution windows. Safari's Intelligent Tracking Prevention caps cookie duration at 24 hours for many third-party trackers, and Firefox blocks third-party cookies by default. A 30-day click window is meaningless if the cookie expires in 24 hours. The platform sees a click, then loses the user. If that user converts on day five, the platform never connects the conversion to the click. The conversion appears in your server-side analytics but not in the ad platform's report. This is one reason server-side conversion tracking matters. When you send conversion data from your server directly to the ad platform, the platform does not rely on a browser cookie to connect the event to the click. Server-side tracking preserves the link between click and conversion even when cookies fail. The practical effect is that your reported conversions increase, not because more people buy, but because more purchases are correctly attributed to ads that caused them. ## Attribution model logic changes the numbers, not just the window The window determines which conversions are eligible. The attribution model determines how much credit each touchpoint gets. You can keep the window fixed and still see different numbers if you change the model. Last-click attribution assigns 100 percent of the credit to the last ad clicked before conversion. This is simple and common, but it ignores every earlier touchpoint. A user who first saw your ad on Facebook, then clicked a Google search ad, then clicked a retargeting ad and bought will give all credit to the retargeting ad under last-click. A data-driven model might give 30 percent to Facebook, 40 percent to Google, and 30 percent to retargeting. The total conversion count stays the same, but the per-campaign numbers change. When you compare a report using last-click with one using a data-driven model, campaigns that served as early touchpoints will look weaker in the last-click report. Position-based models give 40 percent credit to the first and last touchpoints and split the remaining 20 percent across middle interactions. Time-decay models give more credit to touchpoints closer to the conversion. Each model answers a different question about campaign effectiveness, and none of them is objectively correct. ## How to compare numbers across platforms reliably You cannot compare raw conversion counts across platforms without aligning three things: the attribution window, the attribution model, and the conversion definition. Here is the sequence to follow. 1. Set the same conversion window in each platform. If you use 30 days in Google Ads, set 30 days in Meta, TikTok, and your analytics tool. 2. Choose the same attribution model. If you use data-driven where available, use last-click everywhere else and document the difference. 3. Define the conversion event identically. A purchase on your site should fire the same event tag to every platform. 4. Export data for the same time period and compare only after the full window has elapsed. A report generated on day one of a 30-day window is incomplete. 5. Check your server-side tracking setup to ensure cookie loss is not silently dropping conversions from certain browsers. Even after alignment, expect small differences. Platforms use different identity graphs and different fraud detection filters. A gap of 5 to 10 percent is normal. A gap of 40 percent usually means one platform is missing conversions due to tracking failures or using a different window than you think. ## What window should you use for your campaigns The optimal window depends on your sales cycle and your reporting cadence. A 7-day click window suits impulse purchases and low-cost products where users decide quickly. A 30-day window fits B2B software, high-ticket items, and any product with a research phase. The risk of a long window is that it credits ads for conversions they did not meaningfully influence. A user who clicked an ad 29 days ago and then bought after seeing a completely different campaign still gets credited to the first ad under last-click. The risk of a short window is that you undercount the campaigns that plant the seed for later conversions. You should also consider view-through conversions. If your product has a short research cycle, view-through data can be noisy. If your product takes weeks to evaluate, view-based windows capture real influence that click-based windows miss. Test both and compare the incremental lift, not just the total number. ## Next step: audit your current attribution settings Check what window and model each of your ad platforms and your analytics tool currently use. Write them down. If they do not match, you are making budget decisions on incomparable data. The fastest fix is to align the windows first, then decide on the model. Before you adjust anything, run a 30 minute ad account audit to see where your tracking and attribution settings stand. That audit will show you which platforms are underreporting due to cookie loss and which campaigns look weak only because of a mismatched window. ## FAQ ### What is a standard attribution window in advertising A standard attribution window is the period after a click or impression during which a conversion is credited to that ad. Common windows are 7 days, 14 days, and 30 days for clicks, and 1 day for views. Platforms set different defaults, so always check the setting before comparing reports. ### Why do Google Ads and Meta show different conversion numbers for the same period Google Ads and Meta use different default attribution windows, different tracking methods, and different attribution models. Google defaults to 30 days for click conversions; Meta defaults to 7 days after click and 1 day after view. Cookie loss also affects each platform differently, so some conversions never get recorded. ### Does a longer attribution window mean more conversions Yes, a longer window usually captures more conversions because it includes users who convert days or weeks after the ad interaction. But those conversions may not be caused by the ad. Longer windows increase the risk of crediting ads for purchases that would have happened anyway. ### What is the difference between click and view attribution windows A click window starts when the user clicks the ad. A view window starts when the user sees the ad without clicking. Click windows are typically longer because a click signals higher intent. View windows are usually 1 day because impressions are weaker signals. ### How does cookie blocking affect attribution windows Cookie blocking shortens the effective tracking period. If a browser deletes a cookie after 24 hours, a 30-day attribution window cannot function for that user. Server-side tracking solves this by sending conversion data directly to the platform, bypassing browser cookies entirely. > Ready for the next step? [advertising operations for agencies](/). ## Related reading - [Server-side conversion tracking: how to enable without double-counting](/blog/en/server-side-conversion-tracking-how-to-enable-without-double-counting) - [When you have enough data to switch an ad off](/blog/en/when-you-have-enough-data-to-switch-an-ad-off) See how this works in ADS Beast: [attribution window](/features/en/tracking). ## Questions and answers ### Why does the same conversion period show different numbers in Google Ads and GA4? Google Ads counts clicks that lead to a conversion within its own attribution window, usually 30 days. GA4 uses a different default window of 30 days but bases it on the last non-direct touch, and it filters out direct sessions. That's why a click from a paid ad may count in one tool but not the other. ### What is the default attribution window in Google Ads? Google Ads uses a 30-day click-based window and a 1-day view-through window by default. You can change the click window to 7, 14, or 90 days depending on your campaign goals. Shortening it to 7 days will reduce the number of conversions reported, while extending it to 90 days will capture more delayed actions. ### How does changing the attribution window affect reported conversions? A shorter window, like 7 days, will only count conversions that happen within a week of the ad click, which lowers the total count. A longer window, like 90 days, will include more conversions but may also attribute sales to ads that only helped early in the journey. The same user action can appear or disappear simply by switching the window setting. ### Which attribution window should I use for a B2B product with a long sales cycle? For B2B, where decisions often take weeks, use a 90-day click window. A 7-day window will miss most leads that convert after nurturing. If you use a 30-day window, you may see about 20-30% fewer conversions than with a 90-day window, so match the window to your actual time-to-purchase. ### Where can I find the current attribution window settings in my analytics platform? In Google Ads, go to Conversions, select the conversion action, and open 'Attribution model' to see the click and view-through windows. In GA4, navigate to Admin, then Attribution Settings, where you can set the lookback window to 7, 30, or 90 days. Each platform stores this setting separately, so they often don't match unless you align them manually.