What is a Lookback Window?

A Lookback Window is the period of time during which a conversion (like an install or purchase) can be attributed to a previous interaction, such as a click or ad view.

For example, if a user clicks an ad on July 1st and installs the app on July 4th, the conversion will be attributed only if the lookback window is at least 3 days.

It defines how far back attribution tools are allowed to “look” to assign credit.

How does it work?

Lookback windows are defined by the attribution platform (MMP or ad network), and vary depending on:

• Type of engagement
  
  

  • Click-to-install (usually 7–30 days)
    
    

  • View-through (usually 24 hours)
    
    

• Channel or partner (e.g., Meta, Google, TikTok)
  
  

• Attribution method (deterministic, probabilistic, SKAN)
  
  

When a conversion happens, the system checks if there's an eligible click or impression within the window. If found, credit is assigned; if not, it may be marked as organic.

For SKAdNetwork, lookback behavior is baked into Apple’s postback windows and isn’t customizable.

Why it matters

Lookback windows impact how you measure campaign performance and allocate budget.

A window that’s too short might miss conversions that took longer to happen. A window that’s too long might over-credit campaigns that had minimal impact.

Understanding your attribution window helps you:

• Interpret ROAS, CPA, and install counts accurately
  
  

• Align internal and external reporting

• Make better decisions about frequency, timing, and spend

  
  

The lookback window defines the “memory” of your attribution logic — and sets the rules for who gets credit.