Shopify Checkout Extensibility

Shopify Scripts stopped working on June 30, 2026, and any checkout discount logic, shipping rules, or custom checkout fields set up on them stopped with them. Shopify Plus stores with custom checkout logic now need it recreated in Checkout Extensibility. Shero audits what was lost or patched in a hurry and recreates it properly.

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16+

Years in business

500+

Projects Delivered

65+

Team Members

98%

Client Retention

Shopify Scripts

Switched off on June 30, 2026

Shopify switched off Scripts on June 30, 2026. We list what each old Script did, from tiered discounts to hidden shipping rates, and rebuild that logic as Shopify Functions.

Cart Transform

Shopify Functions in production

For Regal Cinemas we created a Cart Transform Function that sets line prices from credits and discounts before checkout, with the credit logic in a custom Shopify app.

Checkout UI extensions

Based on Shopify's hosted checkout

Checkout UI extensions add blocks like delivery notes or gift messages at set spots in checkout, and Shopify hosts them. Shopify can update its checkout without breaking them, which was a constant problem with edited checkout.liquid files.

Shopify Functions

Discount, shipping and payment rules rebuilt

Functions replace Scripts for custom discounts, hiding or renaming shipping and payment options, and cart validation. We write them inside a custom app installed only on your store, so the logic stays under your control.

Since partnering with Shero Commerce, our eCommerce revenue has grown by 200%. Their support and solutions have been game changers for our business.

James McKenna, Senior Commerce and CX Manager, STX

What Shopify Checkout Extensibility covers

Checkout Extensibility is Shopify Plus's framework for customizing checkout without modifying checkout.liquid. It has four components: UI Extensions for adding custom content, Functions for customizing discount and shipping logic, the Branding API for visual customization, and Post-Purchase Extensions for upsell pages after order completion. Shero delivers Checkout Extensibility migrations and new implementations for Plus stores. Migrations cover auditing the old Scripts logic, rebuilding it as Shopify Functions, and testing it before it goes live. New implementations cover checkout upsells, trust signals, custom form fields, and post-purchase pages.

Scripts replacement: rebuild the checkout logic Scripts handled until June 30, 2026 as Shopify Functions
UI Extensions: trust badges, progress bars, custom content within checkout
Checkout upsells: product recommendations within the checkout flow
Custom form fields: order notes, gift messages, delivery instructions
Post-purchase pages: upsell offers right after the order is placed
Branding API: full checkout visual customization matching brand identity

Compared on	Shopify checkout development agency	A checkout app from the App Store	A freelance developer	An in-house developer
Credits and custom discounts	Regal Cinemas: credit and discount logic developed as a custom app	Common discount types covered	Possible, with Functions experience	Needs time to learn Functions
Fields and upsells at checkout	Checkout UI extensions for fields, upsells and messages	Prebuilt blocks, set up in minutes	Made to your brief	Developed once they learn the extension API
Tracking pixels	Analytics moved to Shopify customer events	Some apps add their own pixel	May be new to the pixel sandbox	Needs time to learn customer events
Thank you and order status pages	Thank you and order status pages rebuilt with extensions	Order status widgets available	Rebuilt page by page	Rebuilt as time allows
How you pay	Paid discovery, then an accurate estimate.	A monthly app fee	Hourly	Salary

Shopify checkout development agency

Credits and custom discounts Regal Cinemas: credit and discount logic developed as a custom app

Fields and upsells at checkout Checkout UI extensions for fields, upsells and messages

Tracking pixels Analytics moved to Shopify customer events

Thank you and order status pages Thank you and order status pages rebuilt with extensions

How you pay Paid discovery, then an accurate estimate.

Compared with

A checkout app from the App Store

Credits and custom discounts Common discount types covered

Fields and upsells at checkout Prebuilt blocks, set up in minutes

Tracking pixels Some apps add their own pixel

Thank you and order status pages Order status widgets available

How you pay A monthly app fee

A freelance developer

Credits and custom discounts Possible, with Functions experience

Fields and upsells at checkout Made to your brief

Tracking pixels May be new to the pixel sandbox

Thank you and order status pages Rebuilt page by page

How you pay Hourly

An in-house developer

Credits and custom discounts Needs time to learn Functions

Fields and upsells at checkout Developed once they learn the extension API

Tracking pixels Needs time to learn customer events

Thank you and order status pages Rebuilt as time allows

How you pay Salary

01

Every Shopify Scripts customization has to be rebuilt after the June 30, 2026 shutdown

Shopify Scripts stopped working on June 30, 2026. Discount logic, shipping rules, loyalty points applied at checkout, and custom line item properties based on Scripts all stopped at the same time. Shero audits every old Scripts dependency, maps each to its Shopify Functions equivalent, and recreates the checkout logic.

02

Checkout UI Extensions add trust signals inside the checkout itself

Checkout UI Extensions allow trust badges, security seals, and guarantee messages to be added within the checkout flow itself, where purchase commitment is highest. Shero implements trust signal extensions targeted at the specific checkout stage where your store's heatmap shows the highest hesitation.

03

Post-purchase upsells reach buyers right after they commit

Post-Purchase Extensions put an offer in front of the customer right after they commit to the order, without interrupting checkout. Shero designs and implements post-purchase upsell pages for Plus stores as part of every Checkout Extensibility engagement. The thank you page optimization page covers the full post-purchase optimization workstream.

04

Extensibility customizations are hosted on Shopify infrastructure

Legacy checkout customizations used checkout.liquid and third-party scripts that could slow checkout load times and break under Shopify platform updates. Checkout Extensibility is hosted on Shopify's own infrastructure. Functions execute server-side. UI Extensions render without injecting external JavaScript. The result is faster checkout, upgrade-safe customizations, and Shop Pay compatibility that checkout.liquid never offered.

05

The Branding API enables full checkout visual customization matching brand identity

The Checkout Extensibility Branding API gives Plus stores full control over checkout visual design: fonts, colors, button styles, form element appearance, and layout. This level of customization was previously impossible in checkout.liquid without extensive hacks that broke on platform updates. Shero implements Branding API configurations that maintain brand consistency through the full purchase flow.

06

Checkout extensibility is required for A/B testing checkout elements on Shopify Plus

Testing checkout elements beyond basic settings requires Checkout Extensibility on Plus. Custom UI components, trust signal placement, and post-purchase page variants can all be A/B tested through Extensibility. Shero sets up structured checkout A/B tests as part of every engagement. The Shopify A/B testing page covers the testing methodology.

Digital products

Ordergroovedigital memberships with free trials and plan changes, connected through custom middleware

Stripesubscriptions and saved cards moved off Stripe at go-live

Shift WorshipShopify

Entertainment

Custom appcredit based checkout rebuilt in a custom Shopify app

+40%faster page loads than legacy Magento

Regal CinemasShopify

Read the case study

Backup camera systems

+32%Google clicks in the 12 weeks after the move from Magento

+65%Google impressions, same 12 weeks vs the 12 before

Camera SourceShopify

Read the case study

Golf Putters and Gear

Swag Golf

Swag Golf is known for its limited-edition, bold golf gear and lifestyle products with a devoted following. Looking to align their online store with their unapologetic brand identity, the brand partnered with Shero to overhaul their Shopify theme, develop a dedicated evergreen product strategy, and drive stronger conversions. The redesign led to a +28% increase in mobile conversion rate and tripled load speed.

Swag Golf

Premium Knives

Benchmade

For more than three decades, Benchmade has been known for producing high-quality knives for everyday carry, hunting, rescue, and outdoor use. Launched on Magento Commerce Cloud in 2018, the brand partnered with Shero to expand online amid rising outdoor consumer demand. Since then, they have seen: +100% revenue growth, +68% transaction growth after relaunch, and a +20% increase in average order value.

Benchmade

Canned Wine

Archer Roose

Archer Roose is a wine company known for producing high-quality, sustainably sourced wines in eco-friendly formats like cans and kegs. Their commitment to small, organic, and biodynamic vineyards has helped them stand out in a competitive market. They saw an increase of +18% in email marketing ROAS and 35% improvement in mobile browsing session duration.

Archer Roose

Musical Instruments

Alto Music

Alto Music, a longtime music retailer with loyal customers, collaborated with Shero to switch from Magento 2 to Shopify. They successfully maintained their popular Altobucks loyalty program while moving to a more user-friendly and cost-efficient platform. The transition ensured all loyalty benefits remained intact, and they achieved a 40% reduction in ongoing maintenance expenses.

Alto Music

Built to load fast and stay fast

Every build goes live with the speed and code standards that keep the store fast after launch.

Core Web Vitals
Templates built and tested to pass on mobile.
Fewer apps
Features built into the theme when an app would slow the store.
Clean code
Online Store 2.0 sections your team can edit without a developer.
QA
Every release tested on desktop, mobile and checkout.

Moving to Checkout Extensibility? Tell us which customizations you have.

Get a quote

01

Discovery and logic audit
In recorded workshops we use Shopify's Scripts customizations report and review old checkout.liquid edits to list every discount, shipping and payment rule, and write the acceptance criteria.
02

Mapping and plan
We decide for each rule whether a Shopify Function, a public app or a checkout UI extension replaces it, and you sign off the mapping.
03

Functions and UI development
We rebuild discount, shipping and payment logic as Shopify Functions and match results against your old rules. Custom fields, banners and post-purchase offers become checkout UI extensions.
04

Testing and UAT
We test every combination with live payments, taxes and shipping rates, and you sign off in UAT before the new checkout goes on.
05

Go-live and hypercare
We switch the new checkout on and stay close after launch, depending on project size.

Frequently asked questions.

Can't find what you're looking for? Reach out to our team.

01

What is Shopify Checkout Extensibility?

Checkout Extensibility is Shopify Plus's framework for customizing the checkout experience without modifying checkout.liquid. It consists of four components: UI Extensions for adding custom content within checkout, Functions for customizing checkout logic like discounts and shipping rules, the Branding API for full visual customization, and Post-Purchase Extensions for upsell pages after order completion. All customizations are hosted on Shopify's own infrastructure.

02

What happened when Shopify Scripts stopped on June 30, 2026?

All customizations made with Shopify Scripts stopped working at the same time. That includes custom discounts, shipping rules, loyalty integrations applied at checkout, custom line item properties, and any third-party app integrations that used Scripts. Shopify gave no grace period. Shero audits what each old Script did, maps it to its Checkout Extensibility equivalent, and redoes the checkout logic.

03

Do we need Shopify Plus for Checkout Extensibility?

You need Shopify Plus. Checkout Extensibility is a Shopify Plus feature. Standard Shopify allows guest checkout, payment method selection, basic checkout branding, and form field optionality but cannot modify the checkout layout, add custom content blocks, or implement post-purchase pages within checkout. If your highest-impact CRO opportunities involve the checkout itself, Plus is worth evaluating specifically for Checkout Extensibility access.

04

What is the difference between checkout.liquid and Checkout Extensibility?

checkout.liquid was a direct template override allowing extensive checkout customization but it was fragile: it broke on Shopify platform updates, was incompatible with Shop Pay and accelerated checkout, and required constant maintenance. It is now deprecated. Checkout Extensibility is the modern framework based on APIs and component-based architecture. Customizations are hosted on Shopify's infrastructure, survive platform updates, are compatible with Shop Pay, and support A/B testing through the Extensibility framework.

05

How long does a Checkout Extensibility migration take?

It depends on the complexity of the checkout logic the old Scripts handled. A store that had basic discount Scripts and one custom form field migrates faster than a store with complex loyalty integrations, custom shipping rules, and multiple checkout trust extensions. Shero scopes the migration after auditing the old Scripts dependencies and gives you a timeline with milestone checkpoints before starting work.

06

Can Checkout Extensibility customizations break our checkout?

They can, if implemented incorrectly. UI Extensions that render in specific checkout positions can conflict with certain payment method flows. Functions with logic errors can block checkout completion for specific cart configurations. Post-purchase pages with incorrect offer logic can create loop states. Shero tests every Extensibility implementation across all active payment methods, device types, and cart configurations before deploying to live traffic.

What our clients say.

We design experiences that make a difference. See what our clients have to say about working with us.

Justrite Safety Group

"The collaboration between us and Shero Commerce on the Justrite multi-store site went beyond what we had hoped for. They are a terrific partner to work with. Their team’s dedication to understanding our unique requirements and delivering a high-quality, customized solution has greatly enhanced our online presence. The new website not only showcases our products effectively but also streamlines the shopping experience for our customers. We couldn’t be happier with the results and look forward to working with Shero Commerce on future projects."

Douglas J. Stang

VP of eCommerce / Justrite Safety Group

CAS Corporation

"Working with Shero has been an absolute pleasure. Putting together and maintaining a website can be a daunting task. Shero has been able to simplify the process for us so that we can focus on the important tasks. Shero’s team is knowledgeable, friendly, and easy to work with… and that helps us as a combined team put together a website that does what we need!"

Tom McNally

GM / CAS Corporation

Invisible Bead Extensions®

"Working with Shero Commerce on our migration from WordPress to Shopify was honestly such a pleasant experience. We’d been on WordPress for five years with tons of content and very specific styling, and moving all of it into one cohesive Shopify site was no small feat, this was a genuinely complex, highly technical migration. But they pulled it off on deadline with zero errors and zero issues. Their team showed up with everything we needed: a project manager, multiple developers, marketing leads, email specialists, and CRO experts, all coordinated through dedicated meetings and a real task management system. They also designed several high impact conversion pages so our digital presence didn’t just function better, it looked beautiful too. Since migrating, we’ve seen an increase in revenue thanks to having one simplified, cohesive platform. I’m so grateful for how seamlessly they executed this, and I’d recommend Shero Commerce to anyone facing a migration like ours."

Jasmine Hadjis

CEO, IBE / Invisible Bead Extensions®

Chromebook Parts

"The Shero team was quick to share insight on so much I didn’t know about paid ad tactics, and they were flexible when we wanted to change approaches on ad campaigns. Overall, I am really grateful for all the help they’ve been able to provide!"

Kara Stalboerger

Digital Marketing Specialist / Chromebook Parts

And you?

Let's build something great together.

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Shopify Checkout Extensibility

What Shopify Checkout Extensibility covers