Attribution windows, explained

What is an attribution window?

An attribution window, also called a lookback window, is the maximum time allowed between an ad interaction and an install or in-app event for that interaction to receive credit. If the install happens inside the window, the touchpoint is eligible. If it happens one minute later, it is not.

Windows exist because influence fades. A tap on an ad an hour before the install very likely caused it. A tap three months earlier probably did not, and crediting it would make that campaign look better than it is.

Click windows and view windows

Most systems keep two separate windows.

• Click-through window: the time after someone taps or clicks an ad. These are longer because a click shows clear intent.
• View-through window: the time after someone sees an ad without tapping it. These are much shorter, often a single day, because a view is weaker evidence.

Some platforms add a third type for video. Google's engaged-view conversions require someone to watch at least 10 seconds of a skippable video ad, or the whole ad if it is shorter. TikTok's help centre describes an engaged view-through option too.

Which platform defaults are verified?

Only some defaults are published clearly on the platforms' own pages, and the table below includes only those. Where a default could not be confirmed from a live primary source, the table says so rather than repeating a commonly quoted figure.

TikTok figures come from search-engine extracts of its help centre, because the pages themselves could not be loaded directly. Treat them as reported rather than confirmed, and check them in your own TikTok account.

Why windows cause discrepancies

Two systems looking at the same install can disagree simply because their windows differ.

A worked example

A shopping app runs ads on Google. Ravi taps a Google ad on 1 March and installs on 20 March.

• Google Ads, with its 30-day default, counts the install as a conversion for that ad.
• An MMP with a 7-day click window does not credit Google, because 19 days have passed. If no other touchpoint qualifies, the install is organic.
• The result: Google shows one more install than the MMP for that campaign.

Now reverse it. If the MMP uses a 30-day window and the network uses 7 days, the MMP may credit installs the network ignores. Neither is wrong; they are answering different questions.

How to align them

1. List the click and view windows for each network and for your MMP.
2. Set the MMP window per network to match where your contract and goals allow.
3. When you compare numbers, filter both sides to the same window, the same time zone and the same date basis.
4. Remember that Google and TikTok report on the day of the ad interaction, while many MMPs report on the install day.

Re-attribution windows

A re-attribution window answers a different question: when an existing user reinstalls or returns, should that count as a new install from a new campaign?

Re-attribution is when an install from a person who has used the app before is credited to a new campaign, because enough time has passed since their last attributed install. Platforms treat this very differently:

• Google Ads counts Android reinstalls by people who had uninstalled as install conversions.
• Firebase counts reinstalls as installs by default.
• Many MMPs only count a reinstall as a new attributed install once a re-attribution window has passed. The length of that window varies by vendor and is usually configurable.
• On iOS, AdAttributionKit marks each postback as a download, redownload or reengagement, so reinstalls can be told apart.

If one tool shows far more installs than another, reinstalls are often the reason.

Re-engagement windows

Re-engagement campaigns target people who already have the app, usually with a deep link that opens a specific screen. A re-engagement window is the time after that click during which in-app events are credited to the re-engagement campaign rather than to the original install source.

Apple's AdAttributionKit supports re-engagement from iOS 18, with these rules:

• Re-engagement is click-only; there is no view-through re-engagement.
• There are no non-winning postbacks for re-engagement.
• The device has 2 days to send the first conversion update.
• Monthly per-app and yearly per-device limits apply.
• Apps can set cooldown periods of 0 to 720 hours for installs and for re-engagement.

On Meta, iOS 14 and later re-engagement campaigns that use Meta's own Aggregated Event Measurement report on a 1-day window. The chapter on deep linking and deferred deep linking covers how the links themselves work.

Choosing your own windows

There is no single correct window. Some general practice guidance:

• Keep view windows short. Long view windows credit ads that people barely noticed.
• Match click windows to your purchase cycle. An impulse game install and a loan app install behave differently.
• Keep windows stable. Changing them mid-quarter makes trends hard to read.
• Write your settings down, so the whole team compares like with like.

For the full chain of how an install reaches the window check, see how an install gets attributed, and for the network side, self-attributing networks.