# Attribution window

> How long after a click or view a conversion can still be credited to it.

Source: https://datacenter.so/glossary/attribution-window
Also called: lookback window, conversion window.

An attribution window, also called a lookback or conversion window, is the time limit on credit. A purchase eight days after a click does not count for that click if the window is seven days.

Defaults differ by tool, which is one reason their numbers differ:

- **Meta:** 7-day click and 1-day view for most website conversion campaigns, plus a 1-day engage-through window since 2026.
- **Google Ads:** 30 days for Search and Display unless you change it, with 1 to 90 days allowed ([Google](https://support.google.com/google-ads/answer/3123169)).
- **GA4:** 90 days for most key events and 30 days for first visits by default ([Google](https://support.google.com/analytics/answer/10597962)).

A longer window credits more sales to the channel, and some of those sales would have happened anyway. A shorter one undercounts channels with long buying cycles. Compare tools only after setting their windows to match, as far as each allows. See [why analytics numbers never match](https://datacenter.so/guides/why-analytics-numbers-dont-match).

## Related terms

- https://datacenter.so/glossary/attribution
- https://datacenter.so/glossary/view-through-conversion
- https://datacenter.so/glossary/last-touch-attribution