What Is a Lookback Window? A Plain-English Guide
. By Ads Daddy.
# What Is a Lookback Window? A Plain-English Guide  A lookback window is the countdown timer on your ad credit. Someone clicks or views your ad, the clock starts, and if they buy inside the window, the ad gets the credit. Buy after it closes? Your reports act like the ad never happened. That's it. But that one setting can make a winning campaign look like a flop, or a dud look like a hero. So let's get it right. ## TL;DR - A lookback window (also called a conversion or attribution window) is the number of days after an ad click or view in which a sale or lead can be credited to that ad. - Google Ads defaults for new conversions: 30 days after a click, 3 days for an engaged view, 1 day for a view-through. - Too short and you under-count slow buyers. Too long and you take credit for sales the ad never earned. - Match the window to your real buying cycle, then keep it consistent when you compare channels. - Changing a window only affects future conversions. It does not rewrite history. ## Table of Contents - [What a lookback window actually is](#what-a-lookback-window-actually-is) - [Click-through vs view-through: two clocks, not one](#click-through-vs-view-through-two-clocks-not-one) - [Why use lookback windows at all?](#why-use-lookback-windows-at-all) - [How window length changes your results](#how-window-length-changes-your-results) - [How to choose the right window for your business](#how-to-choose-the-right-window-for-your-business) - [Common mistakes (and how to dodge them)](#common-mistakes-and-how-to-dodge-them) - [Lookback windows are only one piece of attribution](#lookback-windows-are-only-one-piece-of-attribution) - [Our perspective: set the window to match the customer, not the dashboard](#our-perspective-set-the-window-to-match-the-customer-not-the-dashboard) - [Want someone else to sweat the settings?](#want-someone-else-to-sweat-the-settings) - [FAQ](#faq) ## What a lookback window actually is Think of it like a dating app. You swipe right on someone (the ad interaction). They message you back three days later (the conversion). Did the swipe cause the chat? Probably. Would you still say so if they replied six months later? Now it's murky. A lookback window is the rule that answers that question for your ads. Google describes it as the period after an ad interaction, such as a click or a video view, during which a conversion is recorded in Google Ads. Set a 7-day window and a purchase on day 8 won't be recorded or show up in your reports. You'll hear a few names for the same idea: - Conversion window (Google Ads' own term) - Attribution window - Lookback attribution window Slightly different wording, same concept. Time limit. Credit. Done. ## Click-through vs view-through: two clocks, not one Most platforms run two separate clocks. **Click-through window.** Starts when someone clicks. Tracks what they do afterwards. Clicks are a strong signal, so these windows are longer. **View-through window.** Starts when someone sees your ad but doesn't click. Tracks what they do afterwards. Impressions are a weaker signal, so these windows are shorter, often as little as one day. Google Ads also has an engaged-view window for video, which covers people who watched a meaningful chunk of your video ad. Here's how the Google Ads defaults for new conversions look side by side: | Interaction | Default window | What it means | |---|---|---| | Click-through | 30 days | A click today can get credit for a sale up to 30 days later | | Engaged-view | 3 days | A real video watch gets credit for 3 days | | View-through | 1 day | A passive impression gets credit for 1 day | You can customise these. Other platforms, including Meta, have their own options, and some channels lock certain windows so you can't change them at all. Always check the settings of each platform instead of assuming they match. ## Why use lookback windows at all? Because without a time limit, attribution becomes fantasy. Imagine a bloke sees your ad in January and buys in November. Did the ad do that? Maybe. Can you prove it? No. A lookback window draws a sensible line so your numbers stay honest. Here's what a window gives you: 1. **A fair rule for credit.** Every conversion is judged by the same clock. 2. **Control over measurement.** Google says conversion window settings give you more control, especially when your buying cycle doesn't fit the default 30 days. 3. **Cleaner decisions.** You know which campaigns to feed and which to cut. 4. **Better early-funnel insight.** A longer window can help show which keywords sit early in the path to a conversion in Attribution reports. If it doesn't change where your money goes, it's trivia. This one changes where your money goes. ## How window length changes your results This is where people trip up. The same campaign, the same customers, the same sales. Different window, different story. Let's run a made-up example. A plumber runs ads for a bathroom renovation. Ten people click in a week. Their purchases happen like this: - 3 buy within 2 days - 3 buy within 10 days - 2 buy within 25 days - 2 buy after 45 days Here's what each window would report: | Window | Conversions credited | Out of 10 clicks | |---|---|---| | 1 day | 0 | 0% | | 7 days | 3 | 30% | | 14 days | 6 | 60% | | 30 days | 8 | 80% | | 60 days | 10 | 100% | This is an illustration, not real client data. The point: a 7-day window would tell this plumber the ads convert at a third of the rate the 30-day window shows. He might switch off a campaign that's actually working. **Too short** means you miss slow buyers and kill good ads. **Too long** means you claim sales that would have happened anyway, and your return looks better than it is. Neither is neutral. Both are choices.  ## How to choose the right window for your business Forget the default for a moment. Ask one question: how long does it take a real customer to go from first ad to money in the bank? ### Step 1: Find your buying cycle Look at your last 30 to 50 customers. Pull the date they first interacted with an ad and the date they bought. Find the typical gap, plus the slow tail. ### Step 2: Match the product A useful rule of thumb: fast-moving, low-cost products suit shorter windows, and considered purchases suit longer ones. Think of it like food. A coffee is an impulse. A catered wedding is a six-week decision. - **Impulse buys** (snacks, cheap accessories, flash sales): a short window, often 1 to 7 days. - **Considered buys** (furniture, software, electronics): think 14 to 30 days or more. - **High-ticket services and finance** (renovations, B2B contracts, loans): the longer, the more honest, often 30 days or beyond. ### Step 3: Match the offer Running a 48-hour discount? A long window will quietly credit sales that came from your email list or a mate's recommendation. Keep it short. Running always-on lead generation for a service business? Give it room. ### Step 4: Match the interaction Click windows are normally longer than view windows, because a click is intent and an impression is background noise. If a platform lets you, set them separately instead of lumping them together. ### Step 5: Write it down Seriously. Note the window you chose, when you chose it and why. Future you will thank present you. ## Common mistakes (and how to dodge them) **Mistake 1: Comparing channels with different windows.** Your Meta report says one thing. Your Google report says another. Part of that gap can simply be that the windows aren't the same. It's like comparing a 100 metre sprint to a 400 metre race and wondering why the times differ. Align the windows where you can, and note where you can't. **Mistake 2: Expecting a change to rewrite history.** Google Ads applies new window settings to conversions going forward. A conversion that wasn't counted under the old window won't be counted retroactively after you change it. So don't panic when you extend a window and last month's numbers stay put. **Mistake 3: Using one window for everything.** Google lets you set a different window for each conversion action. A newsletter sign-up and a $5,000 purchase don't share a timeline. Give them different clocks. **Mistake 4: Assuming broken tracking when it's just the window.** A sale that lands outside your window simply won't show up, even if your tracking works perfectly. Before you tear apart your pixels, check the window length and whether view-through is switched on. **Mistake 5: Trusting view-through blindly.** View-through credit can flatter your numbers. Someone who was going to buy anyway scrolled past your ad and now it's a "conversion". Treat it as a supporting actor, not the star. **Mistake 6: Ignoring fixed windows.** Some channels and campaign types set windows you can't edit. If you can't change it, you can at least know about it and read the report with that in mind. ## Lookback windows are only one piece of attribution The window tells you how long the clock runs. It doesn't tell you who gets credit when several ads touch the same customer. That's the job of your attribution model, and the two work as a pair. If you want the deeper dive, start with our guide on [how lookback windows impact ads](https://adsdaddy.com/au/blog/how-lookback-windows-impact-ads-2026-guide). For the bigger picture, read [what ad attribution is](https://adsdaddy.com/au/blog/what-is-ad-attribution-a-2026-guide-for-marketers) and how [click attribution](https://adsdaddy.com/au/blog/what-is-click-attribution) works step by step. And here's one that saves budgets: ads that start the journey often look useless in last-click reports. Read [why you should track assisted conversions](https://adsdaddy.com/au/blog/why-track-assisted-conversions) before you fire your best performers. If customers switch between phone and laptop before buying, [cross-device tracking](https://adsdaddy.com/au/blog/what-is-cross-device-tracking) matters too, because a lost device link can look like a lost sale. ## Our perspective: set the window to match the customer, not the dashboard We manage campaigns across Meta, Google, YouTube, LinkedIn and Microsoft. Here's what we see again and again. Business owners judge ads on whatever number the dashboard shows first. That number is shaped by a window someone else picked. The platform's default is a starting point, built for a typical advertiser who doesn't exist. So we do three things. 1. **We start with the customer's real timeline.** If a finance lead takes two weeks to turn into a signed deal, a 1-day window is a lie. 2. **We compare like with like.** Same windows across channels wherever the platforms allow it, and a clear note where they don't. 3. **We check the money, not just the report.** Platform numbers are a guide. Revenue and signed work are the truth. If the two disagree, we dig into the window, the tracking and the model before we touch the budget. The biggest wins rarely come from fancy tricks. They come from making sure you're measuring the right thing, so every dollar goes to what's actually working. You can read more on that in our piece on [using ad analytics to boost ROI](https://adsdaddy.com/au/blog/role-of-data-analytics-ads). > *— Adrian* ## Want someone else to sweat the settings? Here's the honest truth. Window settings, attribution models, tracking tags, policy rules. It's a lot, and every hour you spend in an ads dashboard is an hour you're not running your business. That's why we exist. We build, run and optimise campaigns across [Meta, Google, YouTube, LinkedIn and Microsoft Ads](https://adsdaddy.com/au), with the tracking set up properly from day one. You don't have to learn the platforms. If you need a steady flow of enquiries, our [lead generation service](https://adsdaddy.com/au/lead-generation) is built for it. For finance businesses, our [pay-per-lead options](https://adsdaddy.com/au/finance-brokers) start from A$70 per lead for consumer car finance and from A$170 per lead for commercial ABN finance. A custom-built lead gen system starts from A$17,500 per setup. **Ready to see what your ads are really doing? [Book a call with us](https://adsdaddy.com/au) and we'll look at your numbers with you.** ## FAQ ### What does lookback window mean? It's the time period after someone interacts with your ad during which a resulting conversion, like a purchase or a lead, is credited to that ad. If the action happens after the window closes, it isn't counted. Platforms also call it a conversion window or attribution window. ### What is the default lookback window in Google Ads? For new conversions, Google Ads uses 30 days for click-through, 3 days for engaged-view and 1 day for view-through. You can customise these for each conversion action. Changes apply from then on and don't alter past data. ### What is the best lookback window for my business? There's no universal best. Check how long your real customers take from first ad to purchase, then set the window to cover most of them. Quick, low-cost purchases suit shorter windows, and considered, higher-cost purchases suit longer ones. ### Why do my Meta and Google numbers never match? Different platforms use different windows, models and rules, and some windows are fixed so you can't change them. Each platform also counts its own touchpoints. Align windows where you can, and use your actual sales records as the final check. ### Does changing the window fix missing conversions? Only going forward. A longer window can capture slower buyers from now on, but it won't bring back conversions that went uncounted under the old setting. If numbers look off, also check your tracking tags and the view-through setting. ## Recommended - [How lookback windows impact ads: 2026 guide](https://adsdaddy.com/au/blog/how-lookback-windows-impact-ads-2026-guide) - [What Is Budget Pacing? A Plain-English Guide for Advertisers](https://adsdaddy.com/blog/what-is-budget-pacing)