Key takeaways
- A cookie window is how long after a click an affiliate still gets credit for a resulting conversion.
- Longer windows reward affiliates for slow-converting buyers; shorter windows favour fresh, direct intent.
- Match the window to your sales cycle — impulse buys need days, considered B2B purchases need weeks.
- Last-click attribution is standard, but it isn't the only option.
- Cookies are getting less reliable; server-side and first-party tracking are the future of attribution.
The cookie window is one of the most consequential — and least understood — settings in an affiliate program. It quietly decides who gets paid for a sale, and setting it wrong either underpays your partners or overpays for sales they didn't really cause. Here's how it works and how to choose yours.
What is an affiliate cookie window?
A cookie window (or attribution window) is the period after someone clicks an affiliate's link during which a resulting purchase is still credited to that affiliate. If you set a 30-day window and a buyer clicks today but purchases in three weeks, the affiliate earns the commission. After the window expires, the click no longer counts.
How does the cookie window affect attribution?
The window length changes who earns credit and how much you pay. A longer window credits affiliates for buyers who take time to decide, which partners love, but it can also pay for sales that other channels really closed. A shorter window ties credit closely to fresh intent but may under-reward affiliates who genuinely plant the seed.
- Longer window (60–90 days): generous to affiliates, good for considered purchases, risks over-attribution.
- Shorter window (1–7 days): conservative, best for impulse buys, risks under-rewarding influence.
- Medium window (30 days): the common default that balances both for most businesses.
The window is also a recruiting signal
Experienced affiliates check your cookie window before they join — a stingy window signals a program that under-credits partners. A reasonable window (30 days is a safe default for many businesses) tells serious affiliates you'll pay fairly for the demand they create.
How long should your cookie window be?
Match the window to how long your buyers actually take to decide. Look at the typical gap between first touch and purchase, then set the window to comfortably cover it without stretching so far that you pay for influence that wasn't really yours.
- Impulse / low-price products: a few days is enough.
- Mid-consideration consumer purchases: 30 days is a sensible default.
- Considered B2B or high-ticket SaaS: 45–90 days reflects a longer evaluation.
What about last-click vs. other attribution models?
Most affiliate programs use last-click within the cookie window — the last affiliate clicked before purchase gets the credit. It's simple and widely understood, but you can also consider first-click (rewarding discovery) or splitting credit. Whatever you choose, state it in your terms so partners know exactly how they're credited.
What does cookieless tracking mean for the future?
Third-party cookies are increasingly blocked or short-lived, so attribution is shifting to server-side and first-party methods. Modern platforms record clicks server-side and tie conversions to first-party identifiers rather than relying solely on a browser cookie, which keeps attribution accurate even as browsers tighten privacy. When evaluating tracking, ask how it copes in a cookieless world.
The cookie window isn't a technical detail — it's a promise to your partners about how fairly you'll credit the demand they create.
What is a typical affiliate cookie window length?
Thirty days is the most common default, balancing fair credit to affiliates against over-attribution. Impulse-purchase products use shorter windows of a few days, while considered B2B or high-ticket purchases often use 45–90 days to match a longer decision cycle.
Does a longer cookie window mean I pay more?
It can. A longer window credits affiliates for buyers who take longer to convert, which increases attributed sales — including some that other channels may have closed. Match the window to your real sales cycle so you reward genuine influence without over-paying.
Will affiliate tracking still work without third-party cookies?
Yes, with modern tracking. As browsers restrict third-party cookies, attribution is moving to server-side click recording and first-party identifiers, which keep crediting affiliates accurately even when browser cookies are blocked or expire early.