popstate event and a full page load.
Fix:
- Open your store in Chrome → DevTools → Network tab. Filter by
upstackor your pixel endpoint. - Navigate to the page where duplicates occur. Watch for two network requests firing for the same event.
- If you see two requests:
- Check if your theme uses AJAX cart functionality — some themes trigger a full page reload after adding to cart, which fires
PageViewagain. - Check if you have a custom Upstack initialization script in addition to the app embed — only one should be active.
- Check if your theme uses AJAX cart functionality — some themes trigger a full page reload after adding to cart, which fires
- Go to Online Store → Themes → Customize → App embeds and ensure only the official Upstackified embed is enabled. Remove any manual
<script>tags referencing Upstack from your theme’slayout.liquidortheme.liquidfiles. - If you’re using a headless or SPA Shopify theme, consult the Shopify integration guide — the pixel should track route changes via the History API, not full page reloads.
Other causes
If the steps above don’t find the duplicate, look for another source firing the same events:- Multiple tracking codes — more than one tracking code installed on your site or in your Shopify theme causes duplicate events. Make sure only one instance of each tracking code is installed.
- A tag firing more than once — if a tag fires multiple times on a page (for example, because it’s embedded in multiple elements), it creates duplicates. In Google Tag Manager, make sure each tag fires only once per page.
- Custom code or apps — custom code or third-party apps that inject scripts into your theme can interfere with the pixel. See Audit third-party app configurations.
Still stuck? Contact support@upstackdata.com with your Pixel ID and a description of the issue. We typically respond within a few hours.
Related guides
Duplicate purchases
Upstack-specific diagnosis, including
event_id deduplication and native-app overlap.Troubleshoot pixel issues
Find competing trackers and verify your pixel with Pixel Helper.