{"id":5896,"date":"2026-10-20T08:51:57","date_gmt":"2026-10-20T08:51:57","guid":{"rendered":"https:\/\/www.liquidwebdevelopers.com\/blog\/?p=5896"},"modified":"2026-10-20T09:03:43","modified_gmt":"2026-10-20T09:03:43","slug":"customizing-the-shopify-plus-checkout-with-ui-extensions","status":"publish","type":"post","link":"https:\/\/www.liquidwebdevelopers.com\/blog\/customizing-the-shopify-plus-checkout-with-ui-extensions\/","title":{"rendered":"Customizing the Shopify Plus Checkout With UI Extensions"},"content":{"rendered":"

The checkout is one of the most critical, conversion-sensitive parts of an online store. Merchants often want to customise it by adding useful elements, adjusting the experience, and tailoring it to their customers’ needs. For a long time, deep checkout customisation on Shopify Plus meant editing `checkout.liquid`. However, Shopify has moved towards a new model: checkout extensibility, with checkout UI extensions providing a modern, supported way to customise the checkout.<\/p>\n

Checkout UI extensions let developers add custom UI<\/a> and functionality at defined extension points in Shopify’s checkout. This approach replaces direct template editing for supported use cases and helps businesses build custom experiences without taking responsibility for maintaining the underlying checkout. Because checkout changes can directly affect customer confidence and conversion, understanding how these extensions work is essential.<\/p>\n

This article covers what checkout UI extensions are, how they differ from `checkout.liquid`, what they let you do, how they work, and how to use them effectively.<\/p>\n

<\/span>What checkout UI extensions are (and the shift from checkout.liquid)<\/span><\/h3>\n

Let’s understand checkout UI extensions and the shift to them. The old way: `checkout.liquid` \u2014 historically, deep checkout customisation on Shopify Plus meant editing a Liquid template to add custom code directly to the checkout. Although this offered flexibility, it also made customisations harder to maintain and potentially vulnerable to changes in Shopify’s checkout. The new way: checkout extensibility and UI extensions \u2014 Shopify’s modern approach allows developers to add custom UI and functionality at defined extension points instead of editing the checkout template directly. Shopify’s approach provides a more structured way to build supported checkout customisations.<\/p>\n

What they are \u2014 checkout UI extensions are components built using Shopify’s extension framework that add custom UI and functionality at specific, Shopify-defined locations in the checkout. These extension points determine where an extension can display content or provide supported functionality. Safe and upgrade-friendly \u2014 because extensions work within Shopify’s supported framework, they reduce reliance on arbitrary template changes and help make checkout customisations easier to maintain. Plus and evolving availability \u2014 advanced checkout customisation capabilities vary by feature and plan, so businesses should verify the current requirements before implementation. You can explore the relevant options through our Shopify Plus services<\/a>. For the latest technical requirements, refer to Shopify’s official checkout UI extensions documentation<\/a>.<\/p>\n

Checkout UI extensions are therefore a modern, supported way to customise checkout through defined extension points. They offer a structured alternative to the older template-editing approach for supported use cases, although the available customisation options depend on Shopify’s APIs, extension points, and plan requirements.<\/p>\n

<\/span>What checkout UI extensions let you do<\/span><\/h3>\n

Checkout UI extensions let you customise the checkout in several ways, depending on the available extension points and feature permissions. Add custom content and messaging \u2014 display trust messages, delivery information, custom notices, and other useful details at supported locations in the checkout. These additions can help answer customer questions and provide reassurance at the point of purchase.<\/p>\n

Add custom fields \u2014 capture additional information, such as delivery instructions, gift messages, or custom order attributes, where the relevant extension capabilities permit it. Before planning a custom field, confirm that the required data can be collected and made available to the relevant parts of your order workflow.<\/p>\n

Add functionality \u2014 provide supported functionality such as relevant offers or other checkout enhancements, depending on the extension point and API capabilities available. Custom UI elements \u2014 add banners, informational components, and other tailored elements within supported areas of the checkout. Branding and experience \u2014 use Shopify’s checkout branding settings alongside extensions to create a more consistent brand experience within the styling options Shopify allows.<\/p>\n

Conversion and AOV elements \u2014 introduce appropriate trust signals and other features designed to support conversion or increase average order value. For upselling, consider whether a checkout offer or a post-purchase offer is the better fit for the customer journey. Any offer should remain relevant and avoid distracting customers from completing their purchases.<\/p>\n

Within defined extension points \u2014 these customisations must use Shopify’s supported extension points, so they do not provide unlimited control over every part of the checkout. This differs from making arbitrary changes to the checkout template, but the available capabilities can cover many common customisation needs. Businesses that need a broader storefront implementation can explore our Shopify store development services<\/a>.<\/p>\n

Checkout UI extensions can add useful content, fields, and functionality while keeping customisation within Shopify’s supported framework. The key is to choose features that solve a genuine customer or business problem rather than adding elements simply because they are available.<\/p>\n

\"Four
Checkout is the one page where a mistake costs money the same day.<\/figcaption><\/figure>\n

<\/span>How they work<\/span><\/h3>\n

A bit on how checkout UI extensions work at a practical level. Built by developers \u2014 checkout UI extensions are developed using Shopify’s extension framework and APIs, so implementation requires the appropriate development skills. Developers create the extension using the supported tools, configure its behaviour, and test it before making it available to customers.<\/p>\n

Deployed to the checkout \u2014 extensions are configured and deployed through Shopify’s app and extension development workflow, then appear at supported extension points. At extension points \u2014 each extension runs at a specific location in the checkout where Shopify permits custom content or functionality. The available locations and capabilities depend on the extension type and current platform requirements.<\/p>\n

Within Shopify’s checkout \u2014 the underlying checkout remains Shopify’s, while extensions add supported customisations rather than replacing the checkout itself. Configuration and logic \u2014 extensions can use configuration and supported APIs to tailor what they display or how they behave, such as presenting relevant information based on available cart or checkout data. The implementation must respect the data and operations permitted by Shopify’s framework.<\/p>\n

Tested and reliable \u2014 checkout customisations must be tested carefully because errors, confusing content, or unnecessary friction can directly affect sales. Developers should verify functionality, compatibility, data handling, and the customer experience before releasing changes. Plus and developer capability \u2014 plan eligibility depends on the particular checkout feature, and building extensions requires appropriate development knowledge and access. Businesses that need custom integrations or extension functionality can explore our Shopify app development services<\/a>.<\/p>\n

In practice, the model is Shopify’s checkout plus custom functionality delivered through supported extensions, rather than direct editing of the underlying checkout template. A successful implementation combines technical compliance with a clear understanding of the customer journey.<\/p>\n

<\/span>How to use them well<\/span><\/h3>\n

Using checkout UI extensions well involves customising thoughtfully, safely, and with conversion in mind. Customise purposefully \u2014 add elements that serve a clear purpose, such as providing useful information, capturing necessary details, or reassuring customers, rather than customising simply because the option exists.<\/p>\n

Prioritise conversion and simplicity \u2014 the checkout’s job is to help customers complete purchases<\/a>, so additions should support that goal without introducing friction. Don’t clutter or complicate \u2014 too many added elements, distractions, or unnecessary steps can make checkout harder to complete, so keep the experience clean and focused.<\/p>\n

Tasteful upsells \u2014 if you introduce upsells, keep them relevant and unobtrusive. Aggressive offers can distract customers or contribute to abandonment, while post-purchase offers may be worth considering when you want to avoid interrupting the original checkout. Use trust and reassurance \u2014 provide helpful information about delivery, returns, or guarantees where appropriate, giving customers confidence at this important stage.<\/p>\n

Test rigorously \u2014 test the functionality and customer experience thoroughly before launch. Where traffic and testing tools allow, use A\/B testing to determine whether a customisation actually improves conversion rather than assuming it will. Measure meaningful outcomes, such as checkout completion, average order value, and customer interactions, while ensuring the test does not introduce unnecessary friction.<\/p>\n

Leverage the supported framework \u2014 use Shopify’s supported extension points and APIs, and review current platform requirements to reduce maintenance risks. Use skilled development \u2014 ensure that the implementation is handled by developers who understand the checkout’s technical constraints and business importance. An extension may work correctly from a technical perspective yet still create a poor customer experience if its content, placement, or behaviour is not carefully considered.<\/p>\n

The key is to customise purposefully, preserve a smooth purchasing experience, test carefully, and use the supported framework to add value without creating unnecessary friction.<\/p>\n

<\/span>A worked example: enhancing a checkout without hurting it<\/span><\/h3>\n

Picture a Shopify Plus brand that wants to improve its checkout. Instead of relying on customisations to `checkout.liquid`, it uses checkout UI extensions to add supported enhancements. At an appropriate extension point, it displays a short reassurance message about delivery or returns to help address customer concerns. It also adds a custom field for delivery instructions if the available extension capabilities support that requirement.<\/p>\n

For additional order value, the brand considers a relevant post-purchase offer rather than interrupting the customer during payment. It uses Shopify’s available checkout branding settings to maintain a consistent brand experience. These changes are implemented within the supported extension framework, leaving Shopify responsible for maintaining the underlying checkout.<\/p>\n

Because checkout is business-critical, the brand tests every change carefully. Developers verify that the extension behaves correctly, that the information is captured as intended, and that the checkout remains usable across relevant devices and scenarios. They also check that the added content does not obscure important information or introduce unnecessary steps.<\/p>\n

If the brand has sufficient traffic and suitable testing tools, it can run an experiment to evaluate whether the changes improve conversion or order value without introducing friction. The result is a more informative and tailored checkout experience that remains within Shopify’s supported framework. The example illustrates the purpose of checkout UI extensions: enhancing the customer journey through supported customisations while keeping usability, reliability, and conversion at the centre of the implementation.<\/p>\n

<\/span>The bottom line<\/span><\/h3>\n

The checkout is one of the most critical, conversion-sensitive parts of an online store, and merchants often want to customise it. Shopify has moved away from the older approach of directly editing `checkout.liquid` towards checkout extensibility, with checkout UI extensions providing a supported way to add custom UI and functionality at defined extension points.<\/p>\n

These extensions can support custom content<\/a>, additional fields, and other enhancements, subject to Shopify’s available APIs, extension points, and plan requirements. They do not provide unlimited control over every part of checkout, so businesses should confirm that the required functionality is supported before planning an implementation.<\/p>\n

Developers build and deploy extensions using Shopify’s framework, while Shopify continues to maintain the underlying checkout. To use extensions effectively, focus on changes that provide genuine value, keep the purchasing experience simple, test functionality thoroughly, and evaluate conversion impact where possible. With the right planning and development, checkout UI extensions can help businesses tailor their checkout while respecting the technical constraints and commercial importance of this part of the customer journey.<\/p>\n

<\/span>Frequently asked questions<\/span><\/h3>\n

What are checkout UI extensions?<\/strong><\/p>\n

Checkout UI extensions are components developed using Shopify’s extension framework to add custom UI and functionality at specific, Shopify-defined checkout locations. They provide a supported approach to checkout customisation, replacing the older template-editing approach for supported use cases. Their capabilities and availability depend on the extension point, API, and applicable Shopify plan requirements.<\/p>\n

What can I do with checkout UI extensions?<\/strong><\/p>\n

Depending on the available extension points and APIs, you can add custom content and messaging, capture additional information, display supported UI components, and introduce relevant checkout enhancements. You can also use Shopify’s checkout branding settings to customise aspects of the checkout’s appearance. However, extensions operate within Shopify’s supported framework and do not allow unrestricted modification of every checkout element.<\/p>\n

Why did Shopify move away from checkout.liquid?<\/strong><\/p>\n

Directly editing `checkout.liquid` could make checkout customisations harder to maintain and more vulnerable to changes in Shopify’s checkout. Checkout extensibility provides a structured approach in which custom functionality is added through supported extension points. Shopify has been migrating merchants away from legacy checkout customisation methods, so businesses should check Shopify’s current documentation for applicable deadlines and requirements.<\/p>\n

How should I customise my checkout with extensions?<\/strong><\/p>\n

Customise with a clear purpose, prioritising conversion, usability, and customer confidence. Add useful information or functionality without cluttering the checkout or introducing unnecessary friction. Use supported extension points, confirm plan eligibility, and test the implementation thoroughly before launch. Where practical, measure the effect of customisations on conversion and customer experience instead of assuming that every addition will improve results.<\/p>\n","protected":false},"excerpt":{"rendered":"

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