--- title: Migrate to the Polaris grid component description: >- Learn how to migrate the Grid component to Polaris web components in checkout and customer account UI extensions. source_url: html: 'https://shopify.dev/docs/apps/build/checkout/migrate-to-web-components/grid' md: >- https://shopify.dev/docs/apps/build/checkout/migrate-to-web-components/grid.md --- # Migrate to the Polaris grid component The Polaris grid component creates CSS Grid-based layouts with rows and columns. It replaces the previous [`Grid`](https://shopify.dev/docs/api/checkout-ui-extensions/2025-07/ui-components/layout-and-structure/grid) component and is available as [``](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid) in API versions 2025-10 and newer. *** ## Updated properties The following properties are different in the Polaris grid component. ### columns The previous `Grid` `columns` prop is now called [`gridTemplateColumns`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-gridtemplatecolumns). The value format changes from an array to a CSS grid template string. | Previous pattern | New pattern | Migration notes | | - | - | - | | `columns={['auto', 'fill']}` | `gridTemplateColumns="auto 1fr"` | `'fill'` becomes `1fr`. | | `columns={['fill', 'fill']}` | `gridTemplateColumns="1fr 1fr"` | Array items become space-separated values. | | `columns={['fill', 'fill', 'fill']}` | `gridTemplateColumns="1fr 1fr 1fr"` | Same pattern for any number of columns. | Because `gridTemplateColumns` accepts standard CSS grid syntax, you can now use `repeat()` and `minmax()` for more flexible layouts: ```tsx ... ... ``` ## Migrating columns to gridTemplateColumns ##### Latest (Preact) ```tsx import '@shopify/ui-extensions/preact'; import {render} from 'preact'; export default function extension() { render(, document.body); } function Extension() { return ( Column 1 Column 2 ); } ``` ##### Pre-Polaris (2025-07) ```tsx import { reactExtension, Grid, Text, } from '@shopify/ui-extensions-react/checkout'; export default reactExtension( 'purchase.checkout.block.render', () => , ); function Extension() { return ( Column 1 Column 2 ); } ``` **Responsive values:** If you used `Style.default().when()` to make this property responsive, container queries replace the `Style` helper. Wrap your content in `` and use `@container` syntax in the property value. Learn more in [Migrate StyleHelper to container queries](https://shopify.dev/docs/apps/build/checkout/migrate-to-web-components/style-helper). ### rows The previous `Grid` `rows` prop is now called [`gridTemplateRows`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-gridtemplaterows). The value format changes from an array to a CSS grid template string. | Previous pattern | New pattern | Migration notes | | - | - | - | | `rows={['auto', 'auto', 'auto']}` | `gridTemplateRows="auto auto auto"` | Array items become space-separated values. | ### spacing The previous `Grid` `spacing` prop has been split into [`gap`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-gap), [`columnGap`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-columngap), and [`rowGap`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-rowgap). | Previous pattern | New pattern | Migration notes | | - | - | - | | `spacing="base"` | `gap="base"` | Single `spacing` value maps to `gap`. | | `spacing={['base', 'loose']}` | `rowGap="base" columnGap="large-200"` | Use separate properties for different row and column gaps. | ## Migrating spacing to gap ##### Latest (Preact) ```tsx import '@shopify/ui-extensions/preact'; import {render} from 'preact'; export default function extension() { render(, document.body); } function Extension() { return ( Item 1 Item 2 Item 3 Item 4 ); } ``` ##### Pre-Polaris (2025-07) ```tsx import { reactExtension, Grid, Text, } from '@shopify/ui-extensions-react/checkout'; export default reactExtension( 'purchase.checkout.block.render', () => , ); function Extension() { return ( Item 1 Item 2 Item 3 Item 4 ); } ``` ### block​Alignment The previous `Grid` `blockAlignment` prop is now called [`alignItems`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-alignitems). | Previous pattern | New pattern | Migration notes | | - | - | - | | `blockAlignment="center"` | `alignItems="center"` | Use `alignItems` to align items within their grid areas. | ## Migrating blockAlignment to alignItems ##### Latest (Preact) ```tsx import '@shopify/ui-extensions/preact'; import {render} from 'preact'; export default function extension() { render(, document.body); } function Extension() { return ( Centered vertically Centered vertically ); } ``` ##### Pre-Polaris (2025-07) ```tsx import { reactExtension, Grid, Text, } from '@shopify/ui-extensions-react/checkout'; export default reactExtension( 'purchase.checkout.block.render', () => , ); function Extension() { return ( Centered vertically Centered vertically ); } ``` ### inline​Alignment The previous `Grid` `inlineAlignment` prop is now called [`justifyItems`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-justifyitems). | Previous pattern | New pattern | Migration notes | | - | - | - | | `inlineAlignment="end"` | `justifyItems="end"` | Use `justifyItems` to align items within their grid areas. | ### border The previous `Grid` `border` shorthand controlled border *style* (for example, `border="dotted"`). On ``, [`border`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-border) controls border *size* by default and accepts a token-based shorthand for size, color, and style: | Pattern | Example | Description | | - | - | - | | `'{size}'` | `border="base"` | Border size only. | | `'{size} {color}'` | `border="base base"` | Border size and color. | | `'{size} {color} {style}'` | `border="base base dashed"` | Border size, color, and style. | | Previous value | New value | Migration notes | | - | - | - | | `'base'` (single solid border) | `border="base"` | Renders a default-size border. | | `'dotted'` | `border="base base dotted"` | Specify size and color before style. | | `'dashed'` | `border="base base dashed"` | Specify size and color before style. | | `'none'` | `border="none"` or omit | No border. | ### border​Width The previous `Grid` `borderWidth` accepted `'base'`, `'medium'`, `'thick'`. The Polaris grid [`borderWidth`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-borderwidth) accepts a reduced keyword set: `'none'`, `'base'`, `'large'`, `'large-100'`, `'large-200'`. | Previous value | New value | Migration notes | | - | - | - | | `'base'` | `'base'` | No change needed. | | `'medium'` | `'large'` | `'medium'` is removed. | | `'thick'` | `'large-200'` | `'thick'` is removed. | ### display The previous `Grid` `display` values `'inline'` and `'block'` are no longer accepted. The Polaris grid [`display`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-display) accepts `'auto'` (the default) and `'none'`. | Previous value | New value | Migration notes | | - | - | - | | `'block'` | `'auto'` (the default) | Omit `display` for default block-level rendering. | | `'inline'` | Removed | Wrap inline content in [``](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/typography-and-content/text) instead. This advice applies only when migrating `display="inline"` usages — direct text children of `` are still valid for non-inline content. | | `'none'` | `'none'` | No change needed. | ### padding The previous `Grid` `padding` prop's accepted values and multi-side shorthand format have changed. Use the following mapping to migrate deprecated tokens: | Previous | New | | - | - | | `'none'` | `'none'` | | `'extraTight'` | `'small-400'` | | `'tight'` | `'small-200'` | | `'base'` | `'base'` | | `'loose'` | `'large-200'` | | `'extraLoose'` | `'large-500'` | The new token scale also adds `'small-500'`, `'small-300'`, `'small-100'`, `'small'`, `'large'`, `'large-100'`, `'large-300'`, and `'large-400'`. For more on the scale system, see [Scale](https://shopify.dev/docs/api/checkout-ui-extensions/latest/using-polaris-components#scale). The multi-side shorthand format has also changed: | Previous | New | | - | - | | Array of 2 or 4 values: `['base', 'none']` | Space-separated string with 1 to 4 values: `"base none"`. The 3-value variant `"block-start inline block-end"` is also supported. | To set padding on a single side or axis, use [`paddingBlock`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-paddingblock) or [`paddingInline`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-paddinginline) instead of `padding`. ### accessibility​Role Several `accessibilityRole` values have been renamed in the Polaris grid component. Update them to the new role names: | Previous value | New value | | - | - | | `'complementary'` | `'aside'` | | `'orderedList'` | `'ordered-list'` | | `'unorderedList'` | `'unordered-list'` | | `'listItem'` | `'list-item'` | Other previously supported roles (`'main'`, `'header'`, `'footer'`, `'section'`, `'navigation'`, `'separator'`, `'status'`, `'alert'`) are accepted unchanged. The Polaris grid also adds the following new roles: | New role | Description | | - | - | | `'list-item-separator'` | Separator between list items. | | `'generic'` | Generic container. | | `'presentation'` | Decorative element. | | `'none'` | No semantic role. | *** ## New properties The Polaris grid component introduces the following new properties: | New prop | Type | Description | | - | - | - | | [`accessibilityVisibility`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-accessibilityvisibility) | `'visible'` \| `'hidden'` \| `'exclusive'` | Controls visibility for assistive technologies. | | [`columnGap`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-columngap) | `string` | Controls horizontal spacing between grid items. | | [`placeContent`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-placecontent) | `string` | Shorthand for setting both `alignContent` and `justifyContent`. | | [`placeItems`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-placeitems) | `string` | Shorthand for setting both `alignItems` and `justifyItems`. | | [`rowGap`](https://shopify.dev/docs/api/checkout-ui-extensions/latest/web-components/layout-and-structure/grid#properties-propertydetail-rowgap) | `string` | Controls vertical spacing between grid items. | ***