Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesShopify Checkout Blocks is an app that lets merchants configure supported checkout customizations as blocks and place them in Shopify’s checkout and accounts editor. A checkout UI extension is the developer platform underneath custom checkout interfaces: an app extension combines a target (where it runs), target APIs (the data and actions it can use), and Shopify-provided UI components (what it renders). They overlap because Shopify says Checkout Blocks blocks are built with UI extensions, but they are not the same job. Merchants configure eligible blocks; developers build custom extensions; Shopify controls which targets, components, plans, and pages are available.
What Shopify Checkout Blocks is
Checkout Blocks is a Shopify app and configuration workflow. After installing it, a merchant can configure supported content or behavior and then place eligible blocks in the checkout and accounts editor. Documented capabilities include custom fields, order-value limits, reordering or hiding payment and delivery methods, and custom discounts with conditional rules.
As an Amazon Associate I earn from qualifying purchases.
A block is a configured unit that can appear in an eligible checkout context. Depending on its type, it might display information, collect a buyer’s input, recommend another product, or affect how available checkout options are presented. The app does not give a merchant unlimited control over every checkout surface. Page eligibility, the store’s plan, block type, display rules, and Shopify’s extension framework all determine what can actually be shown.
What a checkout UI extension is
A checkout UI extension is a developer-built app extension for an eligible Shopify checkout context. Shopify describes three connected parts:
#1 Best Overall
- Targets: the extension point and execution context. A target determines where the extension runs and what capabilities it receives.
- Target APIs: the data and actions exposed to that target, such as information the extension may read or supported operations it may request.
- UI components: Shopify-provided interface components used to render the extension.
This model is deliberately constrained. An extension does not receive unrestricted access to the checkout page. It cannot manipulate the real checkout DOM, inject arbitrary HTML, or override the checkout with its own CSS. The components and styling options available to it depend on the target. Shopify’s documentation summarizes the relationship this way: targets define where checkout UI extensions appear and what capabilities they receive.
In practical terms, a developer writes an app extension against Shopify’s APIs and components, declares one or more targets in the extension configuration, and associates each target with the code module that should run. A merchant then sees that extension only where its target, plan, page, and configuration permit it.
How Checkout Blocks and UI extensions fit together
The easiest way to avoid confusion is to separate the three layers:
Windows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallOutdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware match| Layer | Who uses it | What it does |
|---|---|---|
| Checkout Blocks app | Merchant or store administrator | Configures supported blocks, rules, content, and behavior, then places eligible blocks in the editor. |
| Checkout UI extension platform | App developer | Provides targets, APIs, and Shopify UI components for custom checkout functionality. |
| Checkout and accounts editor | Merchant or store administrator | Controls the position of eligible blocks and extensions where Shopify allows repositioning. |
Shopify says Checkout Blocks blocks are built with UI extensions. That explains the technical overlap, not a merger of responsibilities. Installing Checkout Blocks is not the same as developing a custom extension. Conversely, developing a UI extension does not automatically make every Checkout Blocks feature available, nor does it bypass plan restrictions.
Targets: where an extension runs and how it behaves
Block targets are repositionable
A block target is a general-purpose placement point that a merchant can move in the checkout and accounts editor, subject to the locations Shopify exposes. Typical examples include product upsells, trust or satisfaction badges, loyalty information, brand messaging, and custom fields. If a target is supported by the editor, the merchant can reposition the block rather than accepting a permanently fixed location.
Static targets stay in a fixed location
A static target renders at a predetermined location. It can still provide useful checkout content, but the merchant cannot drag it to an arbitrary position. Static placement is appropriate when Shopify defines one specific context for the experience.
Runnable targets provide functionality without rendering a block
A runnable target handles functionality without displaying UI components. This is useful when an extension needs to perform an operation exposed by its target rather than add a visible panel, message, or field. Because it does not render a block, it should not be evaluated using the same placement expectations as a block or static target.
What determines whether a block appears
Adding a block in the editor does not guarantee that every buyer will see it. Display is conditional. The relevant checks include:
- Supported page: the block or extension must be eligible for that checkout or account page.
- Block type: each type has its own supported locations and behavior.
- Display rules: configured conditions can restrict when the block is shown.
- Priority: when several eligible blocks compete for space or execution, priority affects which ones are selected.
- Block ID: some block types use IDs to identify placeholders or specific placements.
- Quantity limits: Shopify caps how many active blocks or placeholders can be displayed.
- Plan eligibility: the store plan can remove a target or feature from the available choices.
Shopify’s overview states that up to 30 active blocks of a given type can display. For applicable block types that use IDs, up to 10 placeholders can be available on each checkout page. These are platform limits, not a promise that 30 blocks will fit usefully on a page; rules, compatibility, and the buyer’s situation can reduce the number shown.
Data-collection placement has an additional practical constraint. A custom field that must capture information before order completion cannot be placed on the Thank you or Order status pages, because those pages occur after the order has been completed.
Which Shopify plans support checkout blocks and extensions?
Plan eligibility depends on the exact feature and placement. Do not treat “checkout blocks” or “UI extensions” as single all-or-nothing entitlements.
Recommended Free Tools
| Capability | Documented availability | Important qualification |
|---|---|---|
| Dynamic content blocks in Checkout Blocks | Basic or higher | Placement is limited to the Thank you and Order status pages under the stated availability. |
| Static content blocks in Checkout Blocks | Basic or higher | Placement is limited to the Thank you and Order status pages under the stated availability. |
| Other Checkout Blocks features | Shopify Plus | The Help Center identifies all other Checkout Blocks features as Plus-only. |
| Checkout UI extensions on information, shipping, and payment steps | Shopify Plus | This restriction applies to those checkout steps; it does not mean every UI extension target requires Plus. |
The distinction matters when planning an implementation. A Basic store may be able to use dynamic or static content blocks on the Thank you or Order status page, while a customization intended for the information, shipping, or payment step may require Shopify Plus. Check the current requirements for the exact target and feature before committing to an app design, because Shopify’s plan and API documentation can change.
What you can add with a block
Product recommendations
A block target can present complementary-product recommendations at an eligible location. The recommendation is an interface extension, not permission to rewrite the checkout markup. The target’s APIs and available components determine what product information and actions can be offered.
Trust, security, and satisfaction messaging
Trust badges and security or satisfaction messages are common block examples. They communicate reassurance within the interface Shopify exposes. Their visual treatment must use supported components and styling rather than arbitrary HTML or CSS.
Loyalty information
A loyalty block can show points or rewards when the extension has access to the necessary data through its target APIs. Whether it can also perform an action, such as applying a benefit, depends on the APIs available in that context.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Brand messaging
Merchant-controlled branding can be rendered in an eligible block location using Shopify’s components. A brand message should be planned around the target’s placement and component limitations; it cannot assume that a custom checkout template or unrestricted stylesheet is available.
Custom fields
Custom fields collect information such as a gift-wrap preference or delivery instruction. Select the page and target based on when the information is needed. A field required before order completion belongs in a pre-completion context, not on the Thank you or Order status page.
Configuring a block in the editor
The exact labels can change as Shopify updates its admin, but the configuration logic is consistent:
- Confirm the plan and feature: identify the intended page, block type, and whether that combination is available on the store’s plan.
- Install or open Checkout Blocks: use the app to create or select the supported block type you need.
- Configure the content or behavior: enter the message, field settings, rule conditions, discount logic, or other options exposed by that block.
- Open the checkout and accounts editor: select the eligible page and add the block or extension to a supported placement point.
- Position the block: drag a block target where the editor permits repositioning. A static target will remain fixed.
- Set display conditions and priority: restrict the audience or circumstances if needed, and resolve ordering when multiple blocks compete.
- Preview and test: check the relevant buyer states, including conditions that should hide the block, and verify that collected data reaches the intended destination.
- Publish only after checking limits: confirm that the page, target, block ID, and quantity limits do not prevent the intended display.
A custom UI extension follows a different workflow: a developer declares its target in the extension configuration, implements the code with the target APIs and Shopify components, deploys it through the app, and then makes the eligible extension available in the editor. The merchant’s placement step does not replace the developer’s implementation work.
Common implementation mistakes and fixes
Expecting arbitrary HTML or CSS
Symptom: a developer plans to copy a full custom checkout template or target an element with a DOM selector. Fix: redesign around Shopify’s supported components and the APIs exposed by the chosen target. The extension cannot access the real checkout DOM or apply unrestricted CSS overrides.
Best Value
- 5 beloved beginner books by Dr. Seuss will be cherished by young & old alike.
- Ideal for reading aloud or reading alone.
- Includes: The Cat in the Hat, One Fish Two Fish Red Fish Blue Fish, Green Eggs and Ham, Hop on Pop and Fox in Socks.
- Perfect gift for new parents, birthday celebrations & happy occasions of all kinds.
Choosing a target before checking the plan
Symptom: an extension works in a development design but the intended information, shipping, or payment placement is unavailable in the store. Fix: verify the store plan and exact target first. Those checkout steps are documented as Shopify Plus-only for Checkout UI extensions.
Assuming every block is movable
Symptom: the editor does not allow a block to be dragged to the desired location. Fix: determine whether it is a static target. Only block targets are repositionable; static targets are fixed by Shopify.
Placing a required field after checkout
Symptom: a field intended to collect delivery instructions is configured on the Thank you or Order status page. Fix: move it to an eligible pre-completion context. Those post-order pages cannot capture information required before the order is completed.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Adding blocks that never appear
Symptom: a configured block is present in the editor but absent for buyers. Fix: check page compatibility, block type, display rules, priority, block ID, quantity limits, and the buyer data that activates the rule. A block can be correctly configured yet filtered out by any one of these conditions.
Treating limits as layout guarantees
Symptom: a team plans a page around the maximum number of blocks. Fix: use the documented ceiling—30 active blocks of a given type, and up to 10 placeholders for applicable ID-based types—as a hard limit, not a design target. Keep the experience understandable and test the actual page.
A practical decision framework
- Use Checkout Blocks configuration when the requirement matches a supported block or rule and a merchant needs to manage it without custom code.
- Build a checkout UI extension when the requirement needs custom logic or an interface that the app’s configured blocks do not provide.
- Choose a block target when the merchant should be able to reposition the interface in the editor.
- Choose a static target when the experience belongs at one Shopify-defined location.
- Choose a runnable target when functionality is required but no visible UI should be rendered.
- Reconsider the design when it depends on DOM manipulation, arbitrary markup, or CSS overrides; those assumptions conflict with the extension model.
Start with the buyer outcome, then map it to the page, target, APIs, components, plan, and display rules. That sequence prevents a technically attractive design from failing at publication because its placement or feature is not eligible.
What to verify before publishing
- The intended page is supported for the selected block or extension target.
- The store plan permits that feature and placement.
- The extension uses only Shopify-provided components and exposed APIs.
- The target type matches the desired behavior: movable block, fixed static target, or non-visual runnable target.
- Display rules, priority, IDs, and quantity limits produce the expected result.
- Any information required before order completion is collected before the order is placed.
- The implementation has been checked against the current Shopify documentation for the applicable API version.
The Bottom Line
Shopify Checkout Blocks is the merchant-facing app for configuring eligible checkout customizations; checkout UI extensions are the developer framework that supplies targets, APIs, and Shopify-controlled components. The correct implementation depends on the exact page, target type, store plan, display rules, and platform limits—not simply on whether a feature is called a “checkout block.”
The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
