> Deprecated: > Product subscription app extensions won't be supported as of December 3, 2025. You should migrate existing product subscription app extensions to [purchase options extensions](/docs/apps/build/purchase-options/purchase-options-extensions). Use to lay out a horizontal row of components. A stack is made of flexible items that wrap each of the stack’s children. Options provide control of the alignment and spacing of the items in the stack. Use `StackItem` to group multiple elements inside a `InlineStack` together.

## Props optional = ? | Name | Type | Description | | --- | --- | --- | | blockAlignment? | "leading" | "center" | "trailing" | "baseline" | Specifies the block alignment. This affects the vertical flow of elements. Default value: 'leading' | | inlineAlignment? | "leading" | "center" | "trailing" | Specifies the inline alignment. This affects the horizontal flow of elements. Default value: 'leading' | | spacing? | Spacing | Adjust spacing between children. Default value: 'base' | ## Guidelines - All children of `InlineStack` are placed in a single view object, which makes recycling the views expensive and results in poorer performance when scrolling. Consider keeping your stacks simple. - By default, `InlineStack` alignment is `'leading’`. | ✅ Do | 🛑 Don't | | ----------------------------------------------------------------------------- | ------------------------------------- | | Keep Inline Stacks shallow. Complex hierarchies have performance penalties | Use complex and deep Stack layouts | For more guidelines, refer to Polaris' [Stack best practices](https://polaris.shopify.com/components/layout-and-structure/stack#best-practices).