What is Attribution Window?
An attribution window (or conversion window) is the period after an ad interaction during which a resulting conversion is credited to that ad. If a user clicks an ad and converts 20 days later, a 30-day click window credits the ad; a 7-day window does not. The window you choose materially changes which channels appear to drive results.
What to know in practice
- Default windows (often 7-day click) under-credit channels with long sales cycles — a B2B SaaS with a 45-day cycle will systematically undervalue its top-of-funnel ads under a 7-day window.
- Match the window to your real decision time: short for DTC e-commerce, long (28-90 day) for B2B, high-ticket services, or considered purchases.
- Google Ads and GA4 maintain separate attribution settings — a mismatch between them is a common reason platform-reported conversions don't reconcile.
- Shortening a window mid-campaign makes performance look worse without anything actually changing; always note window changes when comparing periods.
Common misconception
A shorter attribution window doesn't make your ads less effective — it just credits fewer of the conversions they actually influenced. Teams that shrink windows to 'be conservative' often cut their best top-of-funnel campaigns based on artificially low numbers.
Related terms
- Offline Conversions → Paid Media
- GCLID (Google Click Identifier) → Paid Media
- Smart Bidding → Paid Media