Why it happens
The Snap Pixel only sees what happens in the browser. The pixel runs in the shopper's browser and sends a PURCHASE event when the order is placed. Snap's own troubleshooting list asks you to test without an ad blocker, because a blocked script sends nothing. A shopper who pays and closes the page early may also never trigger the event. Snap recommends running its Conversions API next to the pixel for this reason: the server sends the purchase even when the browser did not.
The Shopify app only covers Shopify pages. The Snapchat Ads app for Shopify installs the pixel through Shopify's web pixel. Snap's help says the app captures events only on pages hosted within Shopify. A headless storefront, or a checkout step on another domain, can lose events. Snap also asks you to turn off any other Snapchat pixel, because two pixels on one store make the counts hard to read.
Pixel and server events do not share an ID. When both the pixel and the Conversions API send the same purchase, Snap merges them only when the pixel's client_dedup_id equals the server's event_id, inside 48 hours. For purchases there is a second pair: the pixel's transaction_id and the server's order_id. Without these, Snap may count one order twice. If one ID is reused for different orders, Snap collapses them and counts too few.
The report uses the day the ad was shown. Snap's default attribution window is 28 days after a click and 1 day after a view. Ads Manager reports by impression time by default, so a purchase today can be credited to the day the ad was shown, weeks ago. You can switch the report to conversion time. A purchase outside the window, or from a shopper who never saw a Snapchat ad, is not counted at all.
Check it yourself
- 1In Shopify admin > Orders, filter by sales channel and keep the online store. Count paid orders for the last 7 full days, without point of sale sales, draft orders and subscription renewals.
- 2In Snapchat Ads Manager, open Events Manager and choose your Pixel. Read the PURCHASE events received for the same days. This view shows what Snap received, not what it attributed to ads.
- 3Install Snap's Pixel Helper extension for Chrome, place a test order in a window without an ad blocker and check that PURCHASE fires on the order confirmation page. If you use the Shopify app, Snap says Pixel Helper shows the integration as "shopify-wpe".
- 4In Events Manager, use Test Events for a second check. Snap marks each test event as valid, valid with warnings or invalid.
- 5Look at the Event Quality Score for PURCHASE in Events Manager. Snap lists the parameters it received and what to add.
- 6If you also send purchases from a server, compare the IDs: the pixel's client_dedup_id must equal the server's event_id, and transaction_id must equal order_id.
- 7In Ads Manager, switch reporting from impression time to conversion time and compare the same week again. If the gap closes, the orders reached Snap and only the date differed.
- 8List every app and script that loads a Snapchat pixel on your store. Keep one.
How a paid order reaches each platform, and which tools send it, is in Shopify conversion tracking.
FAQ
Why does Events Manager show more purchases than Ads Manager?
Events Manager counts what Snap received. Ads Manager counts only purchases it can tie to a Snapchat ad inside the attribution window.
Can old orders still be sent to Snap?
Snap's Conversions API refuses events older than 7 days, so a missed order can only be sent within that time.
Does a server connection replace the pixel?
Snap recommends both together. The pixel adds browser details such as the _scid cookie and the ScCid click ID that help Snap match the buyer.
Should Snap's count equal my Shopify orders?
No. Shopify counts every paid order. Snap counts the ones it received and can tie to its ads.