What it means
The Cookie Window is the period during which a conversion is still attributed to the affiliate's click — commonly 24 hours to 90 days. A longer window gives the affiliate more chances to be credited if the customer buys later, making it a key metric when comparing programs.
The cookie window is a timer set when a visitor first clicks an affiliate link. During that period any qualifying purchase is credited to the affiliate, even if the buyer leaves and returns later through a different route. Windows commonly range from 24 hours to 90 days, though some programs offer 7-day, 120-day, or even lifetime attribution depending on how competitive they want their terms to be.
Mechanically, the window is enforced by a timestamp stored in a cookie or in the network's server-side record. When a conversion fires, the platform checks whether the elapsed time since the last qualifying click falls inside the window; if it does, the commission is attributed, and if not, the sale is treated as non-affiliate. Because most programs use last-click logic, a fresh click from another affiliate can reset or reassign the window before the original one expires.
Longer windows matter most for products with slow consideration cycles, such as software, travel, or high-ticket goods, where buyers rarely purchase on the first visit. Advertisers weigh generous windows against the risk of paying commissions on sales they might have won anyway, so a long window is partly a recruiting incentive and partly a cost decision. Affiliates should read the window alongside the attribution model, since a 90-day window under first-click behaves very differently from 90 days under last-click.
The practical value of cookie windows has eroded as browsers cap or delete third-party and even first-party cookies. Safari's Intelligent Tracking Prevention shortens client-side cookie lifetimes to as little as 24 hours or 7 days regardless of the stated window, which is a major reason networks have shifted toward server-side and postback tracking that does not depend on the browser honoring the full duration.
Key points
- Timer starts on the click, not on the impression
- Typical durations span 24 hours to 90 days, sometimes lifetime
- Longer windows suit slow, high-consideration purchases
- Browser cookie limits can cut the effective window short
- Must be read together with the attribution model
Example
A program offers a 30-day cookie window under last-click. A user clicks an affiliate's link on day 1 but buys on day 20 after returning directly; the affiliate still earns credit because the purchase falls inside the 30 days. Had the user clicked a rival affiliate's link on day 18, that later click would reset attribution and the second affiliate would be paid instead.