Virtuoso API Reference

All properties are optional - by default, the component will render empty. Under the hood, both Virtuoso and GroupedVirtuoso are the same component - the only difference is that they have different TypeScript interfaces applied. All Virtuoso props work for GroupedVirtuoso, but the properties in the GroupedVirtuoso section work only in grouped mode.

If you are using TypeScript and want to use correctly typed component ref, you can use the VirtuosoHandle and the GroupedVirtuosoHandle types.

import { Virtuoso, VirtuosoHandle } from 'react-virtuoso'
//...
const ref = useRef<VirtuosoHandle>(null)
//...
<Virtuoso ref={ref} /*...*/ />

Virtuoso Properties

"components".VirtuosoProps

Type parameters

Name
D

Hierarchy

  • {}

    VirtuosoProps

Properties

alignToBottom

Optional alignToBottom: boolean

Defined in src/components.tsx:198

Setting alignToBottom to true aligns the items to the bottom of the list if the list is shorter than the viewport. Use followOutput property to keep the list aligned when new items are appended.


atBottomStateChange

Optional atBottomStateChange: (atBottom: boolean) => void

Defined in src/components.tsx:177

Called with true / false when the list has reached the bottom / gets scrolled up. Can be used to load newer items, like tail -f.


atTopStateChange

Optional atTopStateChange: (atTop: boolean) => void

Defined in src/components.tsx:182

Called with true / false when the list has reached the top / gets scrolled down.


components

Optional components: Components

Defined in src/components.tsx:76

Use the components property for advanced customization of the elements rendered by the list.


computeItemKey

Optional computeItemKey: ComputeItemKey<D>

Defined in src/components.tsx:86

If specified, the component will use the function to generate the key property for each list item.


data

Optional data: readonly D[]

Defined in src/components.tsx:31

The data items to be rendered. If data is set, the total count will be inferred from the length of the array.


defaultItemHeight

Optional defaultItemHeight: number

Defined in src/components.tsx:97

By default, the component assumes the default item height from the first rendered item (rendering it as a "probe").

If the first item turns out to be an outlier (very short or tall), the rest of the rendering will be slower, as multiple passes of rendering should happen for the list to fill the viewport.

Setting defaultItemHeight causes the component to skip the "probe" rendering and use the property value as default height instead.


endReached

Optional endReached: (index: number) => void

Defined in src/components.tsx:161

Gets called when the user scrolls to the end of the list. Receives the last item index as an argument. Can be used to implement endless scrolling.


firstItemIndex

Optional firstItemIndex: number

Defined in src/components.tsx:150

Use when implementing inverse infinite scrolling - decrease the value this property in combination with data or totalCount to prepend items to the top of the list.

Warning: the firstItemIndex should be a positive number, based on the total amount of items to be displayed.


fixedItemHeight

Optional fixedItemHeight: number

Defined in src/components.tsx:110

Can be used to improve performance if the rendered items are of known size. Setting it causes the component to skip item measurements.


followOutput

Optional followOutput: FollowOutput

Defined in src/components.tsx:137

If set to true, the list automatically scrolls to bottom if the total count is changed. Set to "smooth" for an animated scrolling.

By default, followOutput scrolls down only if the list is already at the bottom. To implement an arbitrary logic behind that, pass a function:

<Virtuoso
followOutput={(isAtBottom: boolean) => {
if (expression) {
return 'smooth' // can be 'auto' or false to avoid scrolling
} else {
return false
}
}} />

headerFooterTag

Optional headerFooterTag: string

Defined in src/components.tsx:142

Set to customize the wrapper tag for the header and footer components (default is div).


increaseViewportBy

Optional increaseViewportBy: number | { bottom: number ; top: number }

Defined in src/components.tsx:46

Set the increaseViewportBy property to artificially increase the viewport size, causing items to be rendered before outside of the viewport. The property causes the component to render more items than the necessary, but can help with slow loading content. Using { top?: number, bottom?: number } lets you set the increase for each end separately.


initialItemCount

Optional initialItemCount: number

Defined in src/components.tsx:71

Use for server-side rendering - if set, the list will render the specified amount of items regardless of the container / item size.


initialScrollTop

Optional initialScrollTop: number

Defined in src/components.tsx:65

Set this value to offset the initial location of the list. Warning: using this property will still run a render cycle at the scrollTop: 0 list window. If possible, avoid using it and stick to initialTopMostItemIndex instead.


initialTopMostItemIndex

Optional initialTopMostItemIndex: number

Defined in src/components.tsx:58

Set to a value between 0 and totalCount - 1 to make the list start scrolled to that item.


isScrolling

Optional isScrolling: (isScrolling: boolean) => void

Defined in src/components.tsx:155

Called when the list starts/stops scrolling.


itemContent

Optional itemContent: ItemContent<D>

Defined in src/components.tsx:81

Set the callback to specify the contents of the item.


itemSize

Optional itemSize: (el: HTMLElement, field: "offsetHeight" | "offsetWidth") => number

Defined in src/components.tsx:104

Allows customizing the height/width calculation of Item elements.

The default implementation reads el.getBoundingClientRect().height and el.getBoundingClientRect().width.


itemsRendered

Optional itemsRendered: (items: ListItem<D>[]) => void

Defined in src/components.tsx:192

Called with the new set of items each time the list items are rendered due to scrolling.


overscan

Optional overscan: number | { main: number ; reverse: number }

Defined in src/components.tsx:39

Set the overscan property to make the component "chunk" the rendering of new items on scroll. The property causes the component to render more items than the necessary, but reduces the re-renders on scroll. Setting { main: number, reverse: number } lets you extend the list in both the main and the reverse scrollable directions. See the increaseViewportBy property for a similar behavior (equivalent to the overscan in react-window).


rangeChanged

Optional rangeChanged: (range: ListRange) => void

Defined in src/components.tsx:171

Called with the new set of items each time the list items are rendered due to scrolling.


scrollSeekConfiguration

Optional scrollSeekConfiguration: ScrollSeekConfiguration | false

Defined in src/components.tsx:117

Use to display placeholders if the user scrolls fast through the list.

Set components.ScrollSeekPlaceholder to change the placeholder content.


scrollerRef

Optional scrollerRef: (ref: HTMLElement | Window | null) => any

Defined in src/components.tsx:208

Provides access to the root DOM element


startReached

Optional startReached: (index: number) => void

Defined in src/components.tsx:166

Called when the user scrolls to the start of the list.


topItemCount

Optional topItemCount: number

Defined in src/components.tsx:53

Set the amount of items to remain fixed at the top of the list.

For a header that scrolls away when scrolling, check the components.Header property.


totalCount

Optional totalCount: number

Defined in src/components.tsx:26

The total amount of items to be rendered.


totalListHeightChanged

Optional totalListHeightChanged: (height: number) => void

Defined in src/components.tsx:187

Called when the total list height is changed due to new items or viewport resize.


useWindowScroll

Optional useWindowScroll: boolean

Defined in src/components.tsx:203

Uses the document scroller rather than wrapping the list in its own.

GroupedVirtuoso Properties

"components".GroupedVirtuosoProps

Type parameters

Name
D

Hierarchy

  • {}

  • {}

    GroupedVirtuosoProps

Properties

groupContent

Optional groupContent: GroupContent

Defined in src/components.tsx:223

Specifies how each each group header gets rendered. The callback receives the zero-based index of the group.


groupCounts

Optional groupCounts: number[]

Defined in src/components.tsx:218

Specifies the amount of items in each group (and, actually, how many groups are there). For example, passing [20, 30] will display 2 groups with 20 and 30 items each.


itemContent

Optional itemContent: GroupItemContent<D>

Defined in src/components.tsx:228

Specifies how each each item gets rendered.

Methods

"components".VirtuosoHandle

Hierarchy

  • {}

    VirtuosoHandle

Methods

scrollBy

scrollBy(location: ScrollToOptions): void

Defined in src/components.tsx:335

Scrolls the component with the specified amount. See ScrollToOptions (MDN)

Parameters:

NameType
locationScrollToOptions

Returns: void


scrollIntoView

scrollIntoView(location: ScrollIntoViewLocation): void

Defined in src/components.tsx:327

Scrolls the item into view if necessary. See the website example for an implementation.

Parameters:

NameType
locationScrollIntoViewLocation

Returns: void


scrollTo

scrollTo(location: ScrollToOptions): void

Defined in src/components.tsx:331

Scrolls the component to the specified location. See ScrollToOptions (MDN)

Parameters:

NameType
locationScrollToOptions

Returns: void


scrollToIndex

scrollToIndex(location: number | IndexLocationWithAlign): void

Defined in src/components.tsx:323

Scrolls the component to the specified item index. See {{IndexLocationWithAlign}} for more options.

Parameters:

NameType
locationnumber | IndexLocationWithAlign

Returns: void