Rates and discounts do different jobs
Shopify controls your shipping profiles, rates, and delivery options. Free Shipping A/B creates and synchronizes free-shipping discounts and storefront messages for published offers. It does not replace your shipping-rate configuration.
Check the whole cart
Before publishing, test an eligible destination and cart below, at, and above the threshold. Check discount combinations, shipping profiles, and the delivery option offered at checkout. Other shipping promotions can make a comparison less meaningful.
Choose the tool for the task
Use Shopify shipping settings or a shipping-rate tool to configure delivery prices and services. Use Free Shipping A/B to compare free-shipping offers and read their measured business results. A threshold calculator helps you screen a scenario before running that comparison.
Check your theme
Enable the app embed in your active theme, select a storefront placement, and verify it on desktop and mobile. Custom cart drawers may need closer inspection. Work through a missing-bar check if the message does not appear.
Start with one working offer
Create your first offer, then verify checkout before you start an experiment. For market-specific behavior, read the Markets guide.