# Checkout UI Extensions

> Customize Shopify checkout safely

**Category:** Shopify  
**Pricing:** open-source  
**URL:** https://shopify.dev/docs/api/checkout-ui-extensions  
**Added:** 2026-08-18

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## The Hook

Checkout Extensions are the only supported way to customize Shopify checkout.

## What's Good

Extension points cover key checkout moments: cart, shipping, payment, and order status. The component library ensures visual consistency. The API handles state without direct DOM manipulation.

## The Catch

The sandboxed environment limits what is possible. Some desired customizations are not supported by extension points.

## Verdict

The only way to customize checkout—work within the limits.