Shopify is turning off the old checkout customization paths, and a lot of stores have tracking and logic sitting in exactly the places being removed. If that is you, things stop working silently rather than throwing an error, which is the dangerous part.
The two old homes for this code:
- The Additional Scripts field (Settings, checkout) where conversion pixels and post-purchase tracking got pasted.
- checkout.liquid customizations in the theme for anything custom on the checkout or thank-you page.
Both are being retired in favor of the Web Pixels API (for tracking) and Checkout Extensibility (for checkout customization). When the old fields turn off, anything still living there stops firing: conversion events, remarketing tags, custom checkout logic. Nothing errors, the numbers just quietly go wrong.
The move is to audit both places, list what is in them, and migrate each item to the new API before the date. Is anyone mid-migration on this, and what was still lurking in your Additional Scripts field when you looked?
Opened Additional Scripts. Found 3 pixels I'd forgotten, one from an ad platform I quit a year ago.
That field turns into a junk drawer.
GA4 and Meta moved to Web Pixels easily. The pain was a thank-you-page upsell buried in checkout.liquid, had to rebuild it as a checkout extension.