Short answer
Each platform counts a conversion inside its own window: Google Ads defaults to 30 days after a click and 1 day after a view, ChatGPT ads offer 7, 14 or 30-day click windows and a 0 or 1-day view window, and GA4 looks back 90 days for most key events. None of them covers a six-month B2B cycle. Set windows consistently, keep view-through separate, and judge pipeline in the CRM by account.
Windows by platform
| Platform | After a click | After a view | Model |
|---|---|---|---|
| Google Ads | Default 30 days; 1–30, 60 or 90 depending on source | Default 1 day (1–30); engaged views default 3 days | Set per conversion action |
| ChatGPT ads | 7, 14 or 30 days | Off or 1 day | Last touch; a click beats an impression |
| Set per conversion; the API lists 1, 7, 28, 30 and 90 days | Set separately per conversion | Per conversion settings | |
| GA4 | Lookback 90 days for most key events (or 30, 60); 30 days for first visits (or 7) | Shares credit across channels | |
Changing a window in Google Ads applies to conversions from that day on, not to history. More detail on ChatGPT ads in attribution windows in ChatGPT ads.
Why the numbers never agree
- Every platform claims its own window. A demo request after a LinkedIn view and a ChatGPT click can count in both.
- GA4 splits credit; ad platforms don't.
- Consent and modelling: some conversions are modelled, others lost to consent choices. Why Ads Manager and GA4 differ.
Settings that work for B2B
| Conversion | Click window | View window | Why |
|---|---|---|---|
| Demo or contact request | 30 days | 1 day, reported separately | Covers most research-to-form gaps |
| Trial sign-up | 14–30 days | 1 day | Shorter consideration |
| Content download | 7–14 days | Off | Low intent; avoid inflating it |
| Opportunity, deal | Not in the ad platform: in the CRM, by account | Cycles run past every window | |
Report the long cycle at account level
- Store first and last-touch UTMs on the contact and the company record. Build them with the UTM builder.
- Mark an opportunity as influenced if its account engaged with ads in the 90 days before it opened.
- Give AI assistants their own GA4 channel with the GA4 AI traffic regex, and add "AI assistant" to "How did you hear about us?".
- Test causality with a holdout group of accounts. How to run one.
Three rules
- Same window for the same conversion across platforms, or comparisons mean nothing.
- View-through in its own column, never added to click conversions.
- Decide budget on account-level pipeline, not on platform-reported conversions.
Questions
Why don't platform conversions match GA4?
Different windows, different attribution models and different counting. Each ad platform claims conversions inside its own window; GA4 shares credit across channels. Expect the totals to differ.
Should B2B use the longest click window?
Use a window that covers your lead cycle, usually 30 days for a form fill or demo request. The deal cycle belongs in the CRM, not in an ad platform window.
Should view-through conversions count?
Report them, but separately. They show reach to people who converted later, not proof the ad caused it.
Does changing a window change past data?
In Google Ads, a new window applies to conversions going forward, not retroactively.
Facts checked against the sources below on 19 October 2026. Ad platforms change quickly: if something here no longer matches what you see, tell us and we will update it.
