Why do Meta Ads and Google Ads report different conversions?

The short answer

Meta Ads and Google Ads count conversions differently. They use different attribution windows, they count views as well as clicks in different ways, they date conversions differently, and both will happily take credit for the same sale. Neither is lying; they are answering different questions. Your own sales data is the tie-breaker.

Five reasons the numbers don't match

1. Different attribution windows

Meta's default attribution setting is 7-day click and 1-day view: a conversion counts if it happens within 7 days of someone clicking your ad, or 1 day of seeing it. Google Ads uses a 30-day click-through window by default for Search and Display conversion actions. Same customer, same purchase on day 12 after a click: Google counts it, Meta (on default settings) does not.

2. Views versus clicks

Meta can credit a conversion to someone who only saw your ad and bought within a day. Google's default view-through window is also 1 day, but Google reports view-through conversions in their own column, separate from the main Conversions column. So Meta's headline number often includes people Google's headline number never would.

3. Both platforms claim the same sale

A buyer clicks a Google search ad on Monday and a Meta ad on Wednesday, then buys on Thursday. Each platform only sees its own touchpoints, so each reports one conversion. Your shop recorded one order. Add the two dashboards together and you get two.

4. Different dates for the same conversion

Google Ads has always reported conversions by the date the ad was clicked, not the date the sale happened (it now also offers "by conversion time" columns). If you compare last week in Google with last week in your CRM, some sales will sit in a different week.

5. Tracking gaps and modelling

Browsers block some tracking, people decline cookies, and some sales happen on the phone or in person. Each platform fills gaps differently, with its own models and its own server-side connections. If one platform gets better data from your site than the other, it will report more.

How to get numbers you can trust

Step 1: Pick one source of truth. Usually that's your CRM, booking system or shop backend. Platforms are for optimising; your own system is for deciding budgets.

Step 2: Line up the windows. When comparing, set the same click window in both places, and compare click-only numbers first.

Step 3: Tag every link. Use consistent UTM parameters on every ad so your analytics and CRM can see where each lead came from.

Step 4: Send real outcomes back. Feed confirmed sales or qualified leads back to each platform, through server-side tracking such as the Meta Conversions API and Google's offline or enhanced conversions. Platforms optimise better on real customers than on form fills.

Step 5: Compare totals, not just platforms. Check total ad spend against total new customers in your own system each month. If both platforms say they grew but your sales didn't, the overlap is the answer.

Step 6: Test incrementality when budgets are big. Pause a channel in one region or for a set period and see what really changes in sales.

The goal isn't matching numbers

You will never get Meta, Google and your CRM to show the same figure, and you don't need to. You need to know which ads bring paying customers and roughly what each customer costs. That is what fixing your ad tracking is about.

Source

• Jon Loomer Digital, Meta Ads Attribution Setting: A Complete Guide (default 7-day click, 1-day view).
• Google Ads Help, About conversion windows (30-day click-through default, 1-day view-through default).
• Google Ads Help, Understand conversions by time with new columns (conversions reported by click date).