Why is my Meta pixel missing sales?

How the pixel normally reports a purchase

The Meta pixel is a piece of JavaScript that runs in your buyer's browser. When the thank-you page loads, it sends a Purchase event to Meta with the order value. Meta then tries to match that event to a person who saw or clicked one of your ads.

That means two things have to go right: the script has to run in the buyer's browser, and Meta has to recognise who the buyer is. Both go wrong more often than you'd think.

Five reasons the purchase never arrives

• Ad blockers and privacy browsers block the pixel script or its network requests completely.
• iOS and Safari limit cookies and tracking, so the link between the ad click and the purchase is lost, especially when buyers come back days later.
• Cookie banners: when a buyer doesn't accept marketing cookies, the pixel may not fire at all.
• In-app browsers (Instagram, Facebook, TikTok) are short-lived. Buyers switch to Safari or Chrome to pay and the click is gone.
• The thank-you page never loads: the buyer closes the tab after paying, the page is slow, or the payment happens on another page or device.

Why it costs you more than a wrong number

Missing purchases don't just make your ROAS look worse. Meta's algorithm learns from the purchases it receives. If it only sees part of your sales, it optimises towards the wrong people and stops spending on ads that actually work.

That's how a profitable ad gets switched off because it 'breaks even' in Ads Manager.

The fix: send purchases from a server as well

Meta's Conversions API (CAPI) lets you send the same Purchase event from a server, straight from your store's order data. No browser, no ad blocker, no thank-you page needed.

To work well, the server event needs the right details: the original ad click (fbclid / fbc), the browser id (fbp), hashed email and phone, and the same event id as the browser pixel — so Meta counts the sale once, not twice.

Doing this yourself means building and maintaining that matching, for every ad platform you use. Tools like Settl do it for you: the ad click is saved when the visitor lands and kept for 90 days, and every paid order is sent to Meta, TikTok, Google (GA4 and Google Ads), Snapchat, Pinterest, X, Microsoft Ads and Reddit from our server. An hourly health check e-mails you if a platform starts failing, a token expires or orders stop arriving.

How to check how much you're missing

Pick a few days. Count the paid orders in your store that came from Meta ads (or all orders, as a rough upper limit) and compare with the purchases in Ads Manager for the same days and attribution window. The difference is your tracking gap.

You can also put your numbers in our ROAS calculator to see what that gap does to the ROAS you're judging your ads on.

Common questions