Custom Checkout is a convenient way for the Customize shopify Checkout Section to purchase section could be better and Custom Checkout helps with One-click Upsell feature to increase your conversion rates by offering an upsell offer during checkout. And provides custom buttons and more to your Shopify store's checkout page. The most important thing about any checkout process is its simplicity. This means that it should be easy for the customer to complete the purchase and go through all the steps in order to buy something.