Shopify & eCommerce
Checkout Extensibility (Shopify)
Quick definition
Shopify Plus's modern checkout customization model using web pixels, UI extensions, and Functions — replacing the deprecated checkout.liquid.
What it actually means
Shopify deprecated checkout.liquid customization for Plus stores in 2024. Checkout Extensibility is the replacement: a component-based, upgrade-safe model using checkout UI extensions (React-like components rendered in checkout), web pixels (event tracking), and Shopify Functions (custom backend logic for discounts, shipping, payments). The shift forces brands with heavy legacy checkout customization (custom fields, conditional shipping, payment logic) to rebuild during migration — a frequent reason for $25k-$150k migration costs.
Related terms
Shopify Plus
Shopify's enterprise tier for brands above ~$1M ARR. Adds checkout extensibility, B2B, multi-store, dedicated launch manager, higher API limits.
Shopify Functions
Server-side WebAssembly modules that run custom logic at checkout — discounts, shipping rules, payment customizations, validation.