How Checkout Extensibility affects Shopify Plus checkout customizations

How Checkout Extensibility affects Shopify Plus checkout customizations

Chris Rausch
February 22, 2023

Checkout is by far one of the most important parts of your website - and the checkout experience plays a massive role in whether a visitor converts to a customer. 

Did you know that approximately 70% of carts are abandoned? Of them, a high percentage - over 60% of users polled - attributed various aspects of the checkout process as the primary cause for not turning into a sale.

Whether it’s unprofessional design, a complex checkout procedure, or few payment methods available, a poor checkout experience can cost you greatly.

Fortunately, Shopify works hard to help you provide the best experience possible for your customers.

With the upcoming deprecation of Shopify’s checkout.liquid, Shopify checkout extensibility is the next step in their pursuit of the optimal checkout process for Shopify Plus brands.

checkout.liquid code

What is checkout.liquid?

If you’re not a developer, chances are that you don’t know what checkout.liquid is - and for a good reason.

Checkout.liquid is a theme file that’s part of your Shopify store, which is customized using code within Shopify platform. It impacts the checkout screen, “thank you” page, and “order status” page by modifying the data that is captured or displayed so that you can tailor the experience for your customers’ benefit (and to improve conversions).

If you have custom functionality or additional tools implemented at checkout, your developer or choice of apps is editing the code within the checkout.liquid Shopify file to make sure those added features are visible while maintaining the checkout’s function.

Without the ability to make changes to the code, you would be stuck with your theme’s basic checkout experience, which means that you couldn’t implement important checkout customization like a Shopify upsell at checkout to increase your average order value (AOV).

Shopify’s checkout.liquid is set to be deprecated starting August 13, 2024, for in-checkout pages but will continue to work for “thank you” and “order status” pages until a later date when checkout extensibility is expanded to support them.

What Is Shopify Plus Checkout Extensibility?

shopify checkout extensibility

Shopify checkout extensibility is an upgrade to Shopify’s existing checkout system specifically for Shopify Plus brands that aims to make it easier to implement and maintain checkout customizations without coding experience.

It takes the time-intensive, code-based checkout.liquid theme file and turns it into an app-based and user-friendly experience that can be customized with a wide range of apps to meet your brand’s specific needs.

Checkout extensibility is intended to act as a direct replacement for checkout.liquid, with future plans to expand the functionality to additional pages that are part of the checkout process to allow for a uniformly-branded user experience.

Checkout Extensibility’s benefits vs checkout.liquid

Checkout Extensibility has a number of benefits when compared to its predecessor.

Code-free visual builder interface

Whether you manage your own site or have a team working on checkout, easier customization is a major benefit of checkout extensibility.

Instead of requiring coding knowledge to make changes to your checkout experience with checkout.liquid, checkout extensibility allows you to use a visual builder where drag-n-drop functionality lets anyone build a custom checkout process.

Plus, your customizations will adopt branding settings inherently so that it’s even quicker to make changes that improve the user experience.


The customizations that go into your checkout experience are likely precise and involve many working parts.

With checkout.liquid, the code that went into these customizations could be put at risk when an upgrade was made to Shopify Checkout that impacted the file’s contents.

You don’t have to worry about updates breaking your checkout page with checkout extensibility - and you’ll be able to automatically receive new features as they’re released so that you can continue to provide the best experience possible.

Extendable functionality with Shopify Functions and apps

The more control you have over your checkout, the more you can impact conversion rates.

Checkout extensibility improves upon the code-dependent nature of checkout.liquid by allowing you to extend functionality and add customization through simpler interfaces.

This includes Shopify Functions, which lets you craft your own logic to deploy on Shopify’s backend without tinkering with the theme file and risking an error. This could be something as simple as adding a sale banner to checkout, creating custom discount logic, or even customizing shipping or payment methods for a truly tailored experience. 

There’s also a vast collection of different apps you can choose from to add features like upsells or post-purchase offers to help increase your AOV - all integrated seamlessly.

Seamless integration with Shop Pay

On top of working with the in-checkout process, checkout extensibility can also be used to customize the streamlined checkout made available by Shop Pay for consistent branding and customization throughout all flows. Shop Pay integration lets you take advantage of the 4x faster speeds and 70+% conversion rate increase Shop Pay offers so that you can maximize your sales.

Pixel tracking

Checkout extensibility makes it easy for you to track important information about user behavior to help tailor your checkout process for more conversions. You can do so by using the new Web Pixel extension for checkout extensibility that allows your apps to access customer events through the Pixels API.

shopify checkout extensibility upgrade

How to upgrade from checkout.liquid to Checkout Extensibility

With checkout.liquid’s deprecation, brands will be forced to upgrade to checkout extensibility on August 13, 2024 - but you don’t have to wait. Shopify Plus brands can upgrade to the improved checkout customizer today.

Before creating a new checkout with checkout extensibility, be sure to review your customizations or work with your developer so that you can note any changes that need to be made so that checkout extensibility’s checkout matches checkout.liquid.

You can do this by going to your theme, selecting “actions”, and clicking on “edit code” to access the file for your checkout. Once you’ve made a note of colors, elements, flow, and everything else that makes your checkout process effective, you can create a new checkout.

To create a new checkout:

  1. Go to settings > checkout and accounts.
  2. Under “checkout customization”, choose “create a draft checkout”.
  3. Create the checkout with or without additional apps and branding.
  4. Publish your draft and replace the current checkout.liquid customization

If you can’t make all the customizations that you need to, consider adding checkout extension apps or creating custom logic using Shopify Functions.

You may also need a developer’s help to create the right app for your needs if nothing else is available, but most checkout.liquid customizations should be replicable to allow you to achieve the same experience as previously.

You can also choose to revert back to checkout.liquid by visiting settings > checkout customization > checkout.liquid and clicking “revert” if your new checkout isn’t working for you.

Your checkout customizations will save as a draft to be used later, but you’ll lose out on functionality that’s exclusive to checkout extensibility.

UpsellPlus: versatile Shopify upsell at checkout for checkout.liquid and Checkout Extensibility

No matter what checkout you plan to use, UpsellPlus and Checkout Extensions can help you make the most of your checkout flow. 

For years UpsellPlus has integrated with checkout.liquid to help brands of all sizes to improve their profitability and increase average order values - and that doesn’t change with the upgrade to checkout extensibility! 

UpsellPlus is an official launch partner for checkout extensibility, making it easy for you to customize your checkout with upsell or cross-sell opportunities that help to increase your sales without negatively impacting your conversion rates. 

Fast, responsive, and effective upsells are as simple as installing the UpsellPlus app to your checkout.liquid or checkout extensibility checkout flow - so get started today!

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