--- title: Box description: A generic container that provides a flexible alternative for custom designs not achievable with existing components. Use it to apply styling such as backgrounds, padding, or borders, or to nest and group other components. The contents of Box always maintain their natural size, making it especially useful within layout components that would otherwise stretch their children. api_version: 2025-10 api_name: checkout-ui-extensions source_url: html: https://shopify.dev/docs/api/checkout-ui-extensions/latest/polaris-web-components/structure/box md: https://shopify.dev/docs/api/checkout-ui-extensions/latest/polaris-web-components/structure/box.md --- # Box A generic container that provides a flexible alternative for custom designs not achievable with existing components. Use it to apply styling such as backgrounds, padding, or borders, or to nest and group other components. The contents of Box always maintain their natural size, making it especially useful within layout components that would otherwise stretch their children. ## Properties * accessibilityLabel string A label that describes the purpose or contents of the element. When set, it will be announced to users using assistive technologies and will provide them with more context. Only use this when the element's content is not enough context for users using assistive technologies. * accessibilityRole AccessibilityRole Default: 'generic' Sets the semantic meaning of the component’s content. When set, the role will be used by assistive technologies to help users navigate the page. * accessibilityVisibility 'visible' | 'hidden' | 'exclusive' Default: 'visible' Changes the visibility of the element. * `visible`: the element is visible to all users. * `hidden`: the element is removed from the accessibility tree but remains visible. * `exclusive`: the element is visually hidden but remains in the accessibility tree. * background 'base' | 'subdued' | 'transparent' Default: 'transparent' Adjust the background of the element. * blockSize MaybeResponsive\ Default: 'auto' Adjust the block size. * border BorderShorthand Default: 'none' - equivalent to \`none base auto\`. Set the border via the shorthand property. This can be a size, optionally followed by a color, optionally followed by a style. If the color is not specified, it will be `base`. If the style is not specified, it will be `auto`. Values can be overridden by `borderWidth`, `borderStyle`, and `borderColor`. * borderRadius MaybeAllValuesShorthandProperty\> Default: 'none' Set the radius of the border. [1-to-4-value syntax](https://developer.mozilla.org/en-US/docs/Web/CSS/Shorthand_properties#edges_of_a_box) is supported. Note that, contrary to the CSS, it uses flow-relative values and the order is: * 4 values: `start-start start-end end-end end-start` * 3 values: `start-start (start-end & end-start) start-end` * 2 values: `(start-start & end-end) (start-end & end-start)` For example: * `small-100` means start-start, start-end, end-end and end-start border radii are `small-100`. * `small-100 none` means start-start and end-end border radii are `small-100`, start-end and end-start border radii are `none`. * `small-100 none large-100` means start-start border radius is `small-100`, start-end border radius is `none`, end-end border radius is `large-100` and end-start border radius is `none`. * `small-100 none large-100 small-100` means start-start border radius is `small-100`, start-end border radius is `none`, end-end border radius is `large-100` and end-start border radius is `small-100`. * borderStyle MaybeAllValuesShorthandProperty\ | "" Default: '' - meaning no override Set the style of the border. If set, it takes precedence over the `border` property's style. Like CSS, up to 4 values can be specified. If one value is specified, it applies to all sides. If two values are specified, they apply to the block sides and inline sides respectively. If three values are specified, they apply to the block-start, both inline sides, and block-end respectively. If four values are specified, they apply to the block-start, block-end, inline-start, and inline-end sides respectively. * borderWidth MaybeAllValuesShorthandProperty\ | '' Default: '' - meaning no override Set the width of the border. If set, it takes precedence over the `border` property's width. Like CSS, up to 4 values can be specified. If one value is specified, it applies to all sides. If two values are specified, they apply to the block sides and inline sides respectively. If three values are specified, they apply to the block-start, both inline sides, and block-end respectively. If four values are specified, they apply to the block-start, block-end, inline-start, and inline-end sides respectively. * display MaybeResponsive<"auto" | "none"> Default: 'auto' Sets the outer display type of the component. The outer type sets a component’s participation in [flow layout](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_flow_layout). * `auto`: the component’s initial value. The actual value depends on the component and context. * `none`: hides the component from display and removes it from the accessibility tree, making it invisible to screen readers. * id string A unique identifier for the element. * inlineSize MaybeResponsive\ Default: 'auto' Adjust the inline size. * maxBlockSize MaybeResponsive\ Default: 'none' Adjust the maximum block size. * maxInlineSize MaybeResponsive\ Default: 'none' Adjust the maximum inline size. * minBlockSize MaybeResponsive\ Default: '0' Adjust the minimum block size. * minInlineSize MaybeResponsive\ Default: '0' Adjust the minimum inline size. * overflow 'hidden' | 'visible' Default: 'visible' Sets the overflow behavior of the element. * `hidden`: clips the content when it is larger than the element’s container. The element will not be scrollable and the users will not be able to access the clipped content by dragging or using a scroll wheel on a mouse. * `visible`: the content that extends beyond the element’s container is visible. * padding MaybeResponsive\> Default: 'none' Adjust the padding of all edges. [1-to-4-value syntax](https://developer.mozilla.org/en-US/docs/Web/CSS/Shorthand_properties#edges_of_a_box) is supported. Note that, contrary to the CSS, it uses flow-relative values and the order is: * 4 values: `block-start inline-end block-end inline-start` * 3 values: `block-start inline block-end` * 2 values: `block inline` For example: * `large` means block-start, inline-end, block-end and inline-start paddings are `large`. * `large none` means block-start and block-end paddings are `large`, inline-start and inline-end paddings are `none`. * `large none large` means block-start padding is `large`, inline-end padding is `none`, block-end padding is `large` and inline-start padding is `none`. * `large none large small` means block-start padding is `large`, inline-end padding is `none`, block-end padding is `large` and inline-start padding is `small`. A padding value of `auto` will use the default padding for the closest container that has had its usual padding removed. * paddingBlock MaybeResponsive\ | ""> Default: '' - meaning no override Adjust the block-padding. * `large none` means block-start padding is `large`, block-end padding is `none`. This overrides the block value of `padding`. * paddingBlockEnd MaybeResponsive\ Default: '' - meaning no override Adjust the block-end padding. This overrides the block-end value of `paddingBlock`. * paddingBlockStart MaybeResponsive\ Default: '' - meaning no override Adjust the block-start padding. This overrides the block-start value of `paddingBlock`. * paddingInline MaybeResponsive\ | ""> Default: '' - meaning no override Adjust the inline padding. * `large none` means inline-start padding is `large`, inline-end padding is `none`. This overrides the inline value of `padding`. * paddingInlineEnd MaybeResponsive\ Default: '' - meaning no override Adjust the inline-end padding. This overrides the inline-end value of `paddingInline`. * paddingInlineStart MaybeResponsive\ Default: '' - meaning no override Adjust the inline-start padding. This overrides the inline-start value of `paddingInline`. ### AccessibilityRole ```ts "main" | "header" | "footer" | "section" | "aside" | "navigation" | "ordered-list" | "list-item" | "list-item-separator" | "unordered-list" | "separator" | "status" | "alert" | "generic" | "presentation" | "none" ``` ### MaybeResponsive ```ts T | `@container${string}` ``` ### SizeUnitsOrAuto ```ts SizeUnits | "auto" ``` ### SizeUnits ```ts `${number}px` | `${number}%` | `0` ``` ### BorderShorthand ```ts ReducedBorderSizeKeyword | `${ReducedBorderSizeKeyword} ${ReducedColorKeyword}` | `${ReducedBorderSizeKeyword} ${ReducedColorKeyword} ${BorderStyleKeyword}` ``` ### ReducedBorderSizeKeyword ```ts 'large' | 'base' | 'large-100' | 'large-200' | 'none' ``` ### ReducedColorKeyword ```ts 'base' ``` ### BorderStyleKeyword ```ts "none" | "solid" | "dashed" | "dotted" | "auto" ``` ### MaybeAllValuesShorthandProperty ```ts T | `${T} ${T}` | `${T} ${T} ${T}` | `${T} ${T} ${T} ${T}` ``` ### SizeUnitsOrNone ```ts SizeUnits | "none" ``` ### PaddingKeyword ```ts SizeKeyword | "none" ``` ### SizeKeyword ```ts "small-500" | "small-400" | "small-300" | "small-200" | "small-100" | "small" | "base" | "large" | "large-100" | "large-200" | "large-300" | "large-400" | "large-500" ``` ### MaybeTwoValuesShorthandProperty ```ts T | `${T} ${T}` ``` ### Examples * #### Code ##### Default ```html Baked fresh to order. Please order 1-2 days before needed due to potential shipping variations. ``` ## Preview ![](https://shopify.dev/images/templated-apis-screenshots/checkout-ui-extensions/2025-10/box-default.png) ## Best Practices * Use `s-box` when you need a container that preserves the natural size of its contents. * `s-box` is particularly useful in layout components like `s-stack` where you want to prevent children from stretching to fit. * `s-box` has a `display: block` layout by default. * Use `s-box` for simple container needs where you don't need the additional features of more specialized components like `s-stack`. * Consider using `s-box` when you need to apply specific styling or layout properties to a group of elements without affecting their natural dimensions.