Checkout extensibility is how Shopify lets apps change checkout without editing checkout.liquid. Apps add blocks to the page and logic behind it through Shopify's own tools, so checkout stays fast and keeps working through Shopify's updates.
The confusing part is that it isn't all Plus-only. Some of it runs on every plan, and that decides what you can plan for.
The two halves: UI extensions and Functions
- Checkout UI extensions control what shoppers see: gifts, upsells, banners, custom fields, trust badges.
- Shopify Functions control logic on Shopify's servers: discounts, hiding or renaming payment methods, and sorting delivery options.
Merchandising teams care most about the first. Operations and finance should know when the second changes pricing or payment behavior.
What Shopify Plus gets, and what every plan gets
| Capability | Shopify Plus | Other plans |
|---|---|---|
| Blocks on the checkout steps (information, shipping, payment) | Yes | No |
| Blocks on the Thank you and Order status pages | Yes | Yes, except Shopify Starter |
| Hide, rename and reorder payment methods | Yes | Yes |
| Hide, rename and sort delivery options | Yes | Yes |
| Checkout branding through apps | Yes | No, use Shopify's checkout editor |
So a store on a standard plan can't add a free gift block to the payment step. It can still hide cash on delivery, rename shipping rates and add blocks after the sale. This guide covers checkout changes without Plus.
What Plus stores usually add to checkout
- Automatic gifts and customer-choice rewards
- Upsell rules tied to what is in the cart
- Trust badges, payment icons and campaign banners
- Custom fields for B2B or compliance notes
- Checkout branding, now that the Checkout Blocks editor is going away
Who should own checkout changes
Growth owns the offer and its copy. Operations owns stock for gift products. Finance signs off margin. Support needs to know what a customer sees when a promotion fails, so they aren't guessing when the tickets arrive.
How to start
- Install an app on a development store or a duplicate store.
- Ship one offer: one threshold gift or one upsell.
- Measure completion rate and average order value for two weeks.
- Add trust content or payment changes once that baseline is stable.
Smart Checkout Widgets covers gifts, upsells, trust content and payment and shipping rules in one app, so you aren't stitching together several single-purpose ones.
Frequently asked questions
What is Shopify Plus checkout extensibility?
It allows approved apps to add UI and logic inside checkout and related surfaces using checkout UI extensions and Shopify Functions, without editing checkout.liquid.
What is the difference between checkout UI extensions and Shopify Functions?
UI extensions control what shoppers see. Functions control backend logic such as discounts, validations, and payment customization.