Migrate to Polaris

Version 2025-07 is the last API version to support React-based UI components. Later versions use web components, native UI elements with built-in accessibility, better performance, and consistent styling with Shopify's design system. Check out the migration guide to upgrade your extension.

Choose a version:

BlockStack

The BlockStack component arranges elements vertically along the block axis with consistent spacing. Use BlockStack to structure vertical layouts, group related content, and control spacing between stacked elements like form fields, text blocks, or cards.

BlockStack supports gap spacing and alignment properties for clean, consistent vertical layouts. For explicit row sizing where each row can have a different proportion, use BlockLayout. For horizontal stacking, use InlineStack.

Support

Targets (25)

Supported targets

Anchor to PropertiesProperties

Configure the following properties on the BlockStack component.

Anchor to accessibilityLabel accessibilityLabel string: A label announced by assistive technologies that describes the purpose or contents of the element. Only set this when the element's visible content doesn't provide enough context on its own.
Anchor to accessibilityRole accessibilityRole: The semantic meaning of the component's content. When set, assistive technologies use this role to help users navigate the page. Accepts a single role or a tuple of two roles (for example, ['listItem', 'separator']).
Anchor to background background <> Default: 'transparent': The background color of the element, set using a design-system keyword.
Anchor to border border <<>>: The border style of the element. Accepts a single value for all four edges, or a shorthand tuple for per-edge control:

'base': Applies base to all edges.

['base', 'none']: Block edges get base, inline edges get none.

['base', 'none', 'dotted', 'base']: Values apply to block-start, inline-end, block-end, and inline-start respectively.
Anchor to borderWidth borderWidth < <> >: The border width of the element. Accepts a single value for all four edges, or a shorthand tuple for per-edge control:

'base': Applies base to all edges.

['base', 'medium']: Block edges get base, inline edges get medium.

['base', 'medium', 'medium', 'base']: Values apply to block-start, inline-end, block-end, and inline-start respectively.
Anchor to cornerRadius cornerRadius < <> >: The corner radius of the element. Accepts a single value for all four corners, or a shorthand tuple for per-corner control using logical (writing-mode-aware) corners:

'base': All four corners get base radius.

['base', 'none']: StartStart/EndEnd get base, StartEnd/EndStart get none. In left-to-right mode, StartStart and EndEnd are the top-left and bottom-right corners.

['base', 'none', 'small', 'base']: Values apply to StartStart, StartEnd, EndEnd, and EndStart respectively.

A borderRadius alias is available. When both are set, cornerRadius takes precedence.
Anchor to display display <'auto' | 'none'> Default: 'auto': The display mode of the component. Learn more about display.

auto: The initial value; the actual behavior depends on the component and context.

none: Hides the component and removes it from the accessibility tree.
Anchor to id id string: A unique identifier for the component. Use this to target the component in scripts or stylesheets, or to distinguish it from other instances of the same component.
Anchor to inlineAlignment inlineAlignment <>: The alignment of children along the inline (main) axis.
Anchor to maxBlockSize maxBlockSize < number | `${number}%` | 'fill' >: The maximum block size (maximum height in horizontal writing modes). The element won't grow taller than this value even if its content is longer.

number: The size in pixels.

`${number}%`: The size as a percentage of the parent container's block size.

'fill': Takes all the available space.

Learn more about the max-block-size property.
Anchor to maxInlineSize maxInlineSize < number | `${number}%` | 'fill' >: The maximum inline size (maximum width in horizontal writing modes). The element won't grow wider than this value.

number: The size in pixels.

`${number}%`: The size as a percentage of the parent container's inline size.

'fill': Takes all the available space.

Learn more about the max-inline-size property.
Anchor to minBlockSize minBlockSize < number | `${number}%` | 'fill' >: The minimum block size (minimum height in horizontal writing modes). The element won't shrink smaller than this value even if its content is shorter.

number: The size in pixels.

`${number}%`: The size as a percentage of the parent container's block size.

'fill': Takes all the available space.

Learn more about the min-block-size property.
Anchor to minInlineSize minInlineSize < number | `${number}%` | 'fill' >: The minimum inline size (minimum width in horizontal writing modes). The element won't shrink narrower than this value.

number: The size in pixels.

`${number}%`: The size as a percentage of the parent container's inline size.

'fill': Takes all the available space.

Learn more about the min-inline-size property.
Anchor to overflow overflow 'hidden' | 'visible' Default: 'visible': The overflow behavior of the element.

visible: Content that extends beyond the container is visible.

hidden: Content that extends beyond the container is clipped and not scrollable.
Anchor to padding padding <<>>: The padding on all edges of the element, using a shorthand syntax. You can specify one, two, or four values following the CSS shorthand convention.

T: A single value applied uniformly to all edges.

[T, T]: The first value applies to block-start and block-end, the second to inline-start and inline-end.

[T, T, T, T]: Values apply to block-start, inline-end, block-end, and inline-start respectively.
Anchor to spacing spacing <> Default: 'base': The spacing between child elements.
Anchor to borderRadius borderRadius < <> >: The corner radius of the element. Accepts a single value for all four corners, or a shorthand tuple for per-corner control:

'base': All four corners get base radius.

['base', 'none']: StartStart/EndEnd get base, StartEnd/EndStart get none.

['base', 'none', 'small', 'base']: Values apply to StartStart, StartEnd, EndEnd, and EndStart respectively.

Deprecated
Use cornerRadius instead.

ViewLikeAccessibilityRole

The accessibility role accepted by view-like layout components. Accepts a single `NonPresentationalAccessibilityRole`, or a tuple of two roles to combine semantic meaning (for example, `['listItem', 'separator']` renders as `<li role='separator'>`).

NonPresentationalAccessibilityRole | [NonPresentationalAccessibilityRole, NonPresentationalAccessibilityRole]

NonPresentationalAccessibilityRole

The subset of accessibility roles available to layout components. Excludes `decorative` and `presentation`, which are only available on the full `AccessibilityRole` type. - `main`: The primary content of the page. - `header`: A page or section header. - `footer`: A section for copyright information, navigation links, and privacy statements. - `section`: A generic section; should have a heading or accessible label. - `complementary`: A supporting section related to the main content. - `navigation`: A major group of navigation links. - `orderedList`: A list of ordered items. - `listItem`: An item inside a list. - `unorderedList`: A list of unordered items. - `separator`: A divider separating sections of content. - `status`: A live region with advisory information that isn't urgent enough to be an alert. - `alert`: Important, usually time-sensitive information.

'main' | 'header' | 'footer' | 'section' | 'complementary' | 'navigation' | 'orderedList' | 'listItem' | 'unorderedList' | 'separator' | 'status' | 'alert'

MaybeConditionalStyle

A type that represents a value that can be a conditional style. We highly recommend using the `Style` helper which simplifies the creation of conditional styles.

T | ConditionalStyle<T, AcceptedConditions>

ConditionalStyle

A conditional style definition that maps one or more conditions to different values. The `default` value is used as a fallback when none of the conditions in `conditionals` are satisfied.

conditionals
An array of conditional values.
```
ConditionalValue<T, AcceptedConditions>[]
```
default
The default value applied when none of the conditional values specified in `conditionals` are met.
```
T
```

ConditionalValue

A single conditional branch that pairs a set of conditions with the value to apply when those conditions are met.

conditions
The conditions that must be met for the value to be applied. At least one condition must be specified.
```
AcceptedConditions
```
value
The value that will be applied if the conditions are met.
```
T
```

Background

A keyword that maps to a predefined background color from the design system. - `transparent`: No background color; the parent's background shows through. - `base`: The standard surface background color. - `subdued`: A muted background color, typically used to de-emphasize content or distinguish secondary areas from the primary surface.

'transparent' | 'base' | 'subdued'

MaybeResponsiveConditionalStyle

A type that represents a value that can be a conditional style. The conditions are based on the viewport size. We highly recommend using the `Style` helper which simplifies the creation of conditional styles.

T | ConditionalStyle<T, ViewportSizeCondition>

ViewportSizeCondition

A condition that targets layouts based on the inline size (width in horizontal writing modes) of the viewport.

viewportInlineSize
The minimum viewport inline size that the condition must match.
```
{ min: T; }
```

MaybeShorthandProperty

A type that accepts either a single value applied to all edges or a shorthand tuple for per-edge control. - `T`: A single value applied uniformly to all edges. - `[T, T]`: The first value applies to block-start and block-end, the second to inline-start and inline-end. - `[T, T, T, T]`: Values apply to block-start, inline-end, block-end, and inline-start respectively.

T | ShorthandProperty<T>

ShorthandProperty

A tuple type that accepts two or four values following the CSS shorthand convention for box edges. - `[T, T]`: The first value applies to block-start and block-end, the second to inline-start and inline-end. - `[T, T, T, T]`: Values apply to block-start, inline-end, block-end, and inline-start respectively.

[T, T] | [T, T, T, T]

BorderStyle

A keyword that maps to a predefined border style from the design system. - `base`: A solid border line, suitable for most use cases. - `dashed`: A dashed border line, often used for drop zones or placeholder boundaries. - `dotted`: A dotted border line. - `none`: No border is rendered.

'base' | 'dashed' | 'dotted' | 'none'

CornerRadius

A keyword that maps to a predefined corner radius from the design system. - `base`: The default corner radius. - `small`: A subtle corner radius, smaller than `base`. - `large`: A pronounced corner radius, larger than `base`. - `fullyRounded`: Fully rounds the corners into a pill or circle shape. - `none`: No corner rounding; sharp square corners.

'base' | 'small' | 'large' | 'fullyRounded' | 'none' | CornerRadiusDeprecated

CornerRadiusDeprecated

'tight' | 'loose'

BorderWidth

A keyword that maps to a predefined border width from the design system. - `base`: The default border width. - `medium`: A medium border width, thicker than `base`. - `thick`: The thickest available border width.

'base' | 'medium' | 'thick'

InlineAlignment

Controls how content is aligned along the inline axis (horizontal in standard writing modes). - `'start'`: Aligns content to the inline start of the container. - `'center'`: Centers content along the inline axis. - `'end'`: Aligns content to the inline end of the container.

'start' | 'center' | 'end'

Spacing

A keyword that maps to a predefined spacing value from the design system. Use these instead of pixel values to ensure consistent spacing throughout the UI. - `none`: No spacing (0px). - `extraTight`: The smallest amount of spacing. - `tight`: A compact amount of spacing, suitable for tight layouts. - `base`: The default spacing, appropriate for most layouts. - `loose`: A generous amount of spacing, used to create visual separation. - `extraLoose`: The largest amount of spacing.

'none' | 'extraTight' | 'tight' | 'base' | 'loose' | 'extraLoose'

Anchor to ExamplesExamples

Anchor to Stack elements verticallyStack elements vertically

Use BlockStack to arrange elements in a vertical column with uniform spacing between them. This example stacks multiple text elements with consistent vertical gaps.

Stack elements vertically

A BlockStack arranging elements in a vertical column.

Stack elements vertically

import {

reactExtension,

BlockStack,

View,

} from '@shopify/ui-extensions-react/customer-account';

export default reactExtension(

'customer-account.page.render',

() => <Extension />,

);

function Extension() {

return (

View

</View>

View

</View>

View

</View>

</BlockStack>

);

}

import {extension, BlockStack, View} from '@shopify/ui-extensions/customer-account';

export default extension('customer-account.page.render', (root) => {

const blockStack = root.createComponent(BlockStack, undefined, [

root.createComponent(View, {border: 'base', padding: 'base'}, 'View'),

]);

root.appendChild(blockStack);

});

React

import {
  reactExtension,
  BlockStack,
  View,
} from '@shopify/ui-extensions-react/customer-account';

export default reactExtension(
  'customer-account.page.render',
  () => <Extension />,
);

function Extension() {
  return (
    <BlockStack>
      <View border="base" padding="base">
        View
      </View>
      <View border="base" padding="base">
        View
      </View>
      <View border="base" padding="base">
        View
      </View>
    </BlockStack>
  );
}

JS

import {extension, BlockStack, View} from '@shopify/ui-extensions/customer-account';

export default extension('customer-account.page.render', (root) => {
  const blockStack = root.createComponent(BlockStack, undefined, [
    root.createComponent(View, {border: 'base', padding: 'base'}, 'View'),
    root.createComponent(View, {border: 'base', padding: 'base'}, 'View'),
    root.createComponent(View, {border: 'base', padding: 'base'}, 'View'),
  ]);

  root.appendChild(blockStack);
});

Anchor to Combine with disclosure for progressive contentCombine with disclosure for progressive content

Use the Disclosure component with inline and block layout components to simplify the interface and reveal content only when the customer requests it.

Combine with disclosure for progressive content

A disclosure component revealing additional content in a vertically stacked layout.

Combine with disclosure for progressive content

import {

reactExtension,

View,

Image,

Icon,

Pressable,

Disclosure,

InlineLayout,

BlockStack,

Text,

Form,

TextField,

Button,

Divider,

InlineStack,

} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(

'purchase.checkout.block.render',

() => <DisclosureAndAlignment />,

);

export const DisclosureAndAlignment = () => {

const openIds = ['one'];

return (

<View

maxInlineSize={400}

cornerRadius="large"

border="base"

<Disclosure

defaultOpen="one"

onToggle={(open) =>

console.log('onToggle event', open)

}

<InlineLayout

blockAlignment="center"

spacing="base"

columns={['auto', 'fill', 'auto']}

<Icon

source="gift"

appearance="subdued"

Gift message

<Icon

source={

openIds.includes('one')

? 'chevronUp'

: 'chevronDown'

}

appearance="subdued"

</InlineLayout>

</Pressable>

<View

id="one"

padding={[

'none',

'base',

]}

<Form

onSubmit={() =>

console.log('onSubmit event')

}

<InlineLayout

columns={['fill', 'fill']}

spacing="base"

<TextField

label="From"

name="from0"

id="from0"

<TextField

label="To"

name="to0"

id="to0"

</InlineLayout>

<TextField

label="Message"

name="message0"

id="message0"

<View>

<Button

accessibilityRole="submit"

kind="secondary"

Save

</Button>

</View>

</BlockStack>

</Form>

</View>

</Disclosure>

<InlineLayout

blockAlignment="baseline"

spacing="base"

columns={['auto', 'fill', 'auto']}

padding="base"

<Icon

source="profile"

appearance="subdued"

<Text>Verify with</Text>

</InlineStack>

<Text

appearance="subdued"

size="small"

15% savings for students and

military

</Text>

</BlockStack>

<Icon

source="external"

appearance="subdued"

</Pressable>

</InlineLayout>

</BlockStack>

</View>

);

};

import {

extension,

BlockStack,

View,

InlineLayout,

InlineStack,

Image,

Pressable,

Icon,

Text,

TextField,

Form,

Button,

Disclosure,

Divider,

} from '@shopify/ui-extensions/checkout';

export default extension(

'purchase.checkout.block.render',

(root) => {

const openIds = ['one'];

const pressable = root.createComponent(

Pressable,

{

toggles: 'one',

padding: 'base',

[

root.createComponent(

InlineLayout,

{

blockAlignment: 'center',

spacing: 'base',

columns: ['auto', 'fill', 'auto'],

React

import {
  reactExtension,
  View,
  Image,
  Icon,
  Pressable,
  Disclosure,
  InlineLayout,
  BlockStack,
  Text,
  Form,
  TextField,
  Button,
  Divider,
  InlineStack,
} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(
  'purchase.checkout.block.render',
  () => <DisclosureAndAlignment />,
);

export const DisclosureAndAlignment = () => {
  const openIds = ['one'];
  return (
    <View
      maxInlineSize={400}
      cornerRadius="large"
      border="base"
    >
      <BlockStack spacing="none">
        <Disclosure
          defaultOpen="one"
          onToggle={(open) =>
            console.log('onToggle event', open)
          }
        >
          <Pressable toggles="one" padding="base">
            <InlineLayout
              blockAlignment="center"
              spacing="base"
              columns={['auto', 'fill', 'auto']}
            >
              <Icon
                source="gift"
                appearance="subdued"
              />
              Gift message
              <Icon
                source={
                  openIds.includes('one')
                    ? 'chevronUp'
                    : 'chevronDown'
                }
                appearance="subdued"
              />
            </InlineLayout>
          </Pressable>
          <View
            id="one"
            padding={[
              'none',
              'base',
              'base',
              'base',
            ]}
          >
            <Form
              onSubmit={() =>
                console.log('onSubmit event')
              }
            >
              <BlockStack>
                <InlineLayout
                  columns={['fill', 'fill']}
                  spacing="base"
                >
                  <TextField
                    label="From"
                    name="from0"
                    id="from0"
                  />
                  <TextField
                    label="To"
                    name="to0"
                    id="to0"
                  />
                </InlineLayout>
                <TextField
                  label="Message"
                  name="message0"
                  id="message0"
                />
                <View>
                  <Button
                    accessibilityRole="submit"
                    kind="secondary"
                  >
                    Save
                  </Button>
                </View>
              </BlockStack>
            </Form>
          </View>
        </Disclosure>
        <Divider />
        <InlineLayout
          blockAlignment="baseline"
          spacing="base"
          columns={['auto', 'fill', 'auto']}
          padding="base"
        >
          <Icon
            source="profile"
            appearance="subdued"
          />
          <BlockStack spacing="none">
            <InlineStack blockAlignment="center">
              <Text>Verify with</Text>
              <Image source="https://via.placeholder.com/50x15" />
            </InlineStack>
            <Text
              appearance="subdued"
              size="small"
            >
              15% savings for students and
              military
            </Text>
          </BlockStack>
          <Pressable to="https://www.shopify.com">
            <Icon
              source="external"
              appearance="subdued"
            />
          </Pressable>
        </InlineLayout>
      </BlockStack>
    </View>
  );
};

JavaScript

import {
  extension,
  BlockStack,
  View,
  InlineLayout,
  InlineStack,
  Image,
  Pressable,
  Icon,
  Text,
  TextField,
  Form,
  Button,
  Disclosure,
  Divider,
} from '@shopify/ui-extensions/checkout';

export default extension(
  'purchase.checkout.block.render',
  (root) => {
    const openIds = ['one'];

    const pressable = root.createComponent(
      Pressable,
      {
        toggles: 'one',
        padding: 'base',
      },
      [
        root.createComponent(
          InlineLayout,
          {
            blockAlignment: 'center',
            spacing: 'base',
            columns: ['auto', 'fill', 'auto'],
          },
          [
            root.createComponent(Icon, {
              source: 'gift',
              appearance: 'subdued',
            }),
            'Gift message',
            root.createComponent(Icon, {
              source: openIds.includes('one')
                ? 'chevronUp'
                : 'chevronDown',
              size: 'small',
            }),
          ],
        ),
      ],
    );

    const disclosureView = root.createComponent(
      View,
      {
        id: 'one',
        padding: ['none', 'base', 'base', 'base'],
      },
      [
        root.createComponent(
          Form,
          {
            onSubmit: () =>
              console.log('onSubmit event'),
          },
          [
            root.createComponent(BlockStack, {}, [
              root.createComponent(
                InlineLayout,
                {
                  columns: ['fill', 'fill'],
                  spacing: 'base',
                },
                [
                  root.createComponent(
                    TextField,
                    {
                      label: 'From',
                      name: 'from0',
                      id: 'from0',
                    },
                  ),
                  root.createComponent(
                    TextField,
                    {
                      label: 'To',
                      name: 'to0',
                      id: 'to0',
                    },
                  ),
                ],
              ),
              root.createComponent(TextField, {
                label: 'Message',
                name: 'message0',
                id: 'message0',
              }),
              root.createComponent(View, {}, [
                root.createComponent(
                  Button,
                  {
                    accessibilityRole: 'submit',
                    kind: 'secondary',
                  },
                  'Save',
                ),
              ]),
            ]),
          ],
        ),
      ],
    );

    const disclosure = root.createComponent(
      Disclosure,
      {
        defaultOpen: 'one',
        onToggle: (open) =>
          console.log('onToggle event', open),
      },
      [pressable, disclosureView],
    );

    const inlineLayout = root.createComponent(
      InlineLayout,
      {
        blockAlignment: 'baseline',
        spacing: 'base',
        columns: ['auto', 'fill', 'auto'],
        padding: 'base',
      },
      [
        root.createComponent(Icon, {
          source: 'profile',
          appearance: 'subdued',
        }),
        root.createComponent(
          BlockStack,
          {
            spacing: 'none',
          },
          [
            root.createComponent(
              InlineStack,
              {
                blockAlignment: 'center',
              },
              [
                root.createComponent(
                  Text,
                  {},
                  'Verify with',
                ),
                root.createComponent(Image, {
                  source:
                    'https://via.placeholder.com/50x15',
                }),
              ],
            ),
            root.createComponent(
              Text,
              {
                appearance: 'subdued',
                size: 'small',
              },
              '15% savings for students and military',
            ),
          ],
        ),
        root.createComponent(
          Pressable,
          {
            to: 'https://www.shopify.com',
          },
          [
            root.createComponent(Icon, {
              source: 'external',
              appearance: 'subdued',
            }),
          ],
        ),
      ],
    );
    const view = root.createComponent(
      View,
      {
        maxInlineSize: 400,
        cornerRadius: 'large',
        border: 'base',
      },
      [
        root.createComponent(
          BlockStack,
          {
            spacing: 'none',
          },
          [
            disclosure,
            root.createComponent(Divider),
            inlineLayout,
          ],
        ),
      ],
    );

    root.appendChild(view);
  },
);

Anchor to Best practicesBest practices

Use consistent spacing: Set the spacing prop to maintain uniform gaps between stacked elements. Use smaller values like tight for related items and larger values like loose for distinct groups.
Choose BlockStack for simple vertical layouts: BlockStack is the go-to component for arranging elements vertically. Only use BlockLayout when you need explicit row sizes.
Set accessibility roles for semantic meaning: Use the accessibilityRole prop to provide landmark roles like main, navigation, or section for assistive technologies.

Anchor to LimitationsLimitations

BlockStack applies the same spacing between all children. For variable spacing between specific elements, use BlockSpacer.
BlockStack doesn't support horizontal layouts. Use InlineStack for horizontal arrangements.
Children are always arranged from top to bottom. Reverse ordering isn't supported.

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