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

"component-interfaces/Virtuoso".VirtuosoProps

Type parameters

Name
D
C

Hierarchy

  • {}

    VirtuosoProps

Properties

alignToBottom

Optional alignToBottom: boolean

Defined in component-interfaces/Virtuoso.ts:209

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 component-interfaces/Virtuoso.ts:188

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


atBottomThreshold

Optional atBottomThreshold: number

Defined in component-interfaces/Virtuoso.ts:238

The property accepts pixel values.

By default 4. Redefine to change how much away from the bottom the scroller can be before the list is not considered not at bottom.


atTopStateChange

Optional atTopStateChange: (atTop: boolean) => void

Defined in component-interfaces/Virtuoso.ts:193

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


atTopThreshold

Optional atTopThreshold: number

Defined in component-interfaces/Virtuoso.ts:231

The property accepts pixel values.

By default 0. Redefine to change how much away from the top the scroller can be before the list is not considered not at top.


components

Optional components: Components<D, C>

Defined in component-interfaces/Virtuoso.ts:87

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


computeItemKey

Optional computeItemKey: ComputeItemKey<D, C>

Defined in component-interfaces/Virtuoso.ts:97

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


context

Optional context: C

Defined in component-interfaces/Virtuoso.ts:34

Additional context available in the custom components and content callbacks


customScrollParent

Optional customScrollParent: HTMLElement

Defined in component-interfaces/Virtuoso.ts:219

Pass a reference to a scrollable parent element, so that the list won't wrap in its own.


data

Optional data: readonly D[]

Defined in component-interfaces/Virtuoso.ts:29

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 component-interfaces/Virtuoso.ts:108

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 component-interfaces/Virtuoso.ts:172

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 component-interfaces/Virtuoso.ts:161

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 component-interfaces/Virtuoso.ts:121

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 component-interfaces/Virtuoso.ts:148

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 component-interfaces/Virtuoso.ts:153

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 component-interfaces/Virtuoso.ts:56

The property accepts pixel values.

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 component-interfaces/Virtuoso.ts:82

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 component-interfaces/Virtuoso.ts:76

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 | IndexLocationWithAlign

Defined in component-interfaces/Virtuoso.ts:69

Set to a value between 0 and totalCount - 1 to make the list start scrolled to that item. Pass in an object to achieve additional effects similar to scrollToIndex.


isScrolling

Optional isScrolling: (isScrolling: boolean) => void

Defined in component-interfaces/Virtuoso.ts:166

Called when the list starts/stops scrolling.


itemContent

Optional itemContent: ItemContent<D, C>

Defined in component-interfaces/Virtuoso.ts:92

Set the callback to specify the contents of the item.


itemSize

Optional itemSize: SizeFunction

Defined in component-interfaces/Virtuoso.ts:115

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 component-interfaces/Virtuoso.ts:203

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


logLevel

Optional logLevel: LogLevel

Defined in component-interfaces/Virtuoso.ts:245

set to LogLevel.DEBUG to enable various diagnostics in the console, the most useful being the item measurement reports.

Ensure that you have "all levels" enabled in the browser console too see the messages.


overscan

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

Defined in component-interfaces/Virtuoso.ts:45

The property accepts pixel values.

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 component-interfaces/Virtuoso.ts:182

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


scrollSeekConfiguration

Optional scrollSeekConfiguration: ScrollSeekConfiguration | false

Defined in component-interfaces/Virtuoso.ts:128

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 component-interfaces/Virtuoso.ts:224

Provides access to the root DOM element


startReached

Optional startReached: (index: number) => void

Defined in component-interfaces/Virtuoso.ts:177

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


topItemCount

Optional topItemCount: number

Defined in component-interfaces/Virtuoso.ts:63

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 component-interfaces/Virtuoso.ts:24

The total amount of items to be rendered.


totalListHeightChanged

Optional totalListHeightChanged: (height: number) => void

Defined in component-interfaces/Virtuoso.ts:198

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


useWindowScroll

Optional useWindowScroll: boolean

Defined in component-interfaces/Virtuoso.ts:214

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

GroupedVirtuoso Properties

"component-interfaces/Virtuoso".GroupedVirtuosoProps

Type parameters

Name
D
C

Hierarchy

  • {}

    GroupedVirtuosoProps

Properties

groupContent

Optional groupContent: GroupContent

Defined in component-interfaces/Virtuoso.ts:258

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


groupCounts

Optional groupCounts: number[]

Defined in component-interfaces/Virtuoso.ts:253

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, C>

Defined in component-interfaces/Virtuoso.ts:263

Specifies how each each item gets rendered.

Methods

"component-interfaces/Virtuoso".VirtuosoHandle

Hierarchy

  • VirtuosoHandle

Methods

autoscrollToBottom

autoscrollToBottom(): void

Defined in component-interfaces/Virtuoso.ts:286

Use this with combination with follow output if you have images loading in the list. Listen to the image loading and call the method.

Returns: void


scrollBy

scrollBy(location: ScrollToOptions): void

Defined in component-interfaces/Virtuoso.ts:282

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

Parameters:

NameType
locationScrollToOptions

Returns: void


scrollIntoView

scrollIntoView(location: FlatScrollIntoViewLocation): void

Defined in component-interfaces/Virtuoso.ts:274

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

Parameters:

NameType
locationFlatScrollIntoViewLocation

Returns: void


scrollTo

scrollTo(location: ScrollToOptions): void

Defined in component-interfaces/Virtuoso.ts:278

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

Parameters:

NameType
locationScrollToOptions

Returns: void


scrollToIndex

scrollToIndex(location: number | FlatIndexLocationWithAlign): void

Defined in component-interfaces/Virtuoso.ts:270

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

Parameters:

NameType
locationnumber | FlatIndexLocationWithAlign

Returns: void