Virtual scroll
Windowed list — 10k rows, ~25 DOM nodes.
- Browsers
- Chrome 123+Firefox 121+Safari 17.5+
- Tier
- 2
- Bundle compressed
- 4.16 kB
- Forced layout budget
- 0 ms
- Axe budget
- 0
- SSR compatible
- Yes
- Published contract
- Test harness
Playground
Virtual scroll
10,000 team members with checkbox, avatar, and dropdown actions. Only visible rows (+ buffer) mount in the DOM — open DevTools and count [data-uiify-virtual-scroll] [data-part="row"] nodes while scrolling.
Horizontal
The same users as a horizontal strip with orientation="horizontal". rowHeight sets each card's width; the window follows the viewport width.
import { VirtualScroll } from "@gunkin/uiify";
const items = Array.from({ length: 10000 }, (_, index) => ({
id: String(index),
label: "Row " + (index + 1),
}));
export default function Example() {
return (
<>
<VirtualScroll className="" height={400} items={items} renderRow={(item) => <div>{item.label}</div>} />
{/* rowHeight is the item size along the scroll axis — here, each card's width. */}
<VirtualScroll
className=""
height={120}
items={items}
orientation="horizontal"
rowHeight={144}
renderRow={(item) => <div>{item.label}</div>}
/>
</>
);
}/* Generic skin for custom core surfaces used by the demo and consumers. */
@layer components {
[data-uiify-surface] {
display: grid;
gap: var(--space-md);
inline-size: max-content;
max-inline-size: min(28rem, calc(100vw - 2 * var(--space-lg)));
padding: var(--space-lg);
border: var(--border-width) solid var(--border);
border-radius: var(--radius-xl);
corner-shape: squircle;
background-color: var(--card);
color: var(--card-foreground);
box-shadow: var(--shadow-popover);
}
[data-uiify-surface][popover]:not(:popover-open) {
display: none;
}
@media (prefers-reduced-motion: no-preference) {
[data-uiify-surface][popover] {
transition: var(--transition-presence);
}
[data-uiify-surface][popover]:not(:popover-open) {
opacity: 0;
scale: var(--presence-scale);
}
@starting-style {
[data-uiify-surface][popover]:popover-open {
opacity: 0;
scale: var(--presence-scale);
}
}
}
}import { VirtualScroll } from "@gunkin/uiify";
const items = Array.from({ length: 10000 }, (_, index) => ({
id: String(index),
label: "Row " + (index + 1),
}));
export default function Example() {
return (
<>
<VirtualScroll
className="
grid gap-md w-max max-w-[min(28rem,calc(100vw_-_2_*_var(--space-lg)))] p-6 border border-border rounded-xl
[corner-shape:squircle] bg-card text-card-foreground shadow-popover [&[popover]:not(:popover-open)]:hidden
motion-safe:[&[popover]]:[transition:var(--transition-presence)]
motion-safe:[&[popover]:not(:popover-open)]:opacity-0
motion-safe:[&[popover]:not(:popover-open)]:[scale:var(--presence-scale)]
motion-safe:starting:[&[popover]:popover-open]:opacity-0
motion-safe:starting:[&[popover]:popover-open]:[scale:var(--presence-scale)]
"
height={400}
items={items}
renderRow={(item) => <div>{item.label}</div>}
/>
{/* rowHeight is the item size along the scroll axis — here, each card's width. */}
<VirtualScroll
className="
grid gap-md w-max max-w-[min(28rem,calc(100vw_-_2_*_var(--space-lg)))] p-6 border border-border rounded-xl
[corner-shape:squircle] bg-card text-card-foreground shadow-popover [&[popover]:not(:popover-open)]:hidden
motion-safe:[&[popover]]:[transition:var(--transition-presence)]
motion-safe:[&[popover]:not(:popover-open)]:opacity-0
motion-safe:[&[popover]:not(:popover-open)]:[scale:var(--presence-scale)]
motion-safe:starting:[&[popover]:popover-open]:opacity-0
motion-safe:starting:[&[popover]:popover-open]:[scale:var(--presence-scale)]
"
height={120}
items={items}
orientation="horizontal"
rowHeight={144}
renderRow={(item) => <div>{item.label}</div>}
/>
</>
);
}/* app.css */
@layer reset, ui, app, tokens, base, demo, components, utilities, theme;
@import "@gunkin/uiify/styles/reset";
@import "@gunkin/uiify/components/behavior.css";
@import "@gunkin/uiify/styles/tokens";
@import "@gunkin/uiify/styles/tailwind";
@import "tailwindcss/utilities.css";
@theme { --spacing: 0.25rem; --font-weight-normal: 400; --font-weight-medium: 500; --font-weight-semibold: 600; --font-weight-bold: 700; }
@source inline('grid gap-md w-max max-w-[min(28rem,calc(100vw_-_2_*_var(--space-lg)))] p-6 border border-border rounded-xl [corner-shape:squircle] bg-card text-card-foreground shadow-popover [&[popover]:not(:popover-open)]:hidden motion-safe:[&[popover]]:[transition:var(--transition-presence)] motion-safe:[&[popover]:not(:popover-open)]:opacity-0 motion-safe:[&[popover]:not(:popover-open)]:[scale:var(--presence-scale)] motion-safe:starting:[&[popover]:popover-open]:opacity-0 motion-safe:starting:[&[popover]:popover-open]:[scale:var(--presence-scale)]');
@layer base { :root { --uiify-control-text: var(--text-sm); } @media (pointer: coarse) { :root { --uiify-control-text: var(--text-base); } } }
/* Authored animation and registered properties used by the Tailwind skin.
* Visual rules belong in utility recipes; only at-rule definitions live here. */
@layer components {
@keyframes uiify-presence-in {
from {
opacity: 0;
scale: var(--presence-scale);
}
}
}
@layer components {
@keyframes uiify-presence-out {
to {
opacity: 0;
scale: var(--presence-scale);
}
}
}
@property --uiify-spinner-tail {
syntax: "<angle>";
inherits: false;
initial-value: 0deg;
}
@property --uiify-spinner-length {
syntax: "<angle>";
inherits: false;
initial-value: 36deg;
}
@layer components {
@keyframes uiify-spinner-rotate {
to {
transform: rotate(360deg);
}
}
}
@layer components {
@keyframes uiify-spinner-orbit {
0% {
--uiify-spinner-tail: 0deg;
--uiify-spinner-length: 36deg;
}
50% {
--uiify-spinner-tail: 90deg;
--uiify-spinner-length: 324deg;
}
100% {
--uiify-spinner-tail: 360deg;
--uiify-spinner-length: 36deg;
}
}
}
@layer components {
@keyframes uiify-skeleton-pulse {
50% {
opacity: 0.45;
}
}
}
@layer components {
@keyframes uiify-skeleton-shimmer {
to {
background-position: -200% 0;
}
}
}
@layer components {
@keyframes uiify-skeleton-reveal {
from {
opacity: 0;
}
to {
opacity: 1;
}
}
}
@property --candle-body-height {
syntax: "<percentage>";
inherits: true;
initial-value: 0%;
}
@property --candle-body-top {
syntax: "<percentage>";
inherits: true;
initial-value: 50%;
}
@property --candle-slot {
syntax: "<percentage>";
inherits: true;
initial-value: 100%;
}
@property --candle-wick-height {
syntax: "<percentage>";
inherits: true;
initial-value: 0%;
}
@property --candle-wick-top {
syntax: "<percentage>";
inherits: true;
initial-value: 50%;
}
@property --candle-x {
syntax: "<percentage>";
inherits: true;
initial-value: 0%;
}
@property --candle-scale {
syntax: "<number>";
inherits: true;
initial-value: 1;
}
@property --line-y {
syntax: "<percentage>";
inherits: true;
initial-value: 50%;
}
@property --line-prev-y {
syntax: "<percentage>";
inherits: true;
initial-value: 50%;
}
@property --line-count {
syntax: "<integer>";
inherits: false;
initial-value: 1;
}
@property --line-scale {
syntax: "<number>";
inherits: true;
initial-value: 1;
}
@layer components {
@keyframes uiify-otp-input-caret-blink {
50% {
opacity: 0;
}
}
}API
VirtualScroll
| Prop | Type | Default | Description |
|---|---|---|---|
items* | T[] | — | The full list of items, each with a stable id; only the rows in the current range are rendered. |
renderRow* | (item: T, index: number) => ReactNode | — | Renders the contents of one row from its item and absolute index. |
height | number | — | Explicit height in pixels. Omit it and pass style={{ blockSize: '100%' }} to fill a definite parent height; 600px is the default when neither is supplied. |
rowHeight | number | 64 | Fixed pixel size of each row on the scroll axis (height when vertical, width when horizontal), used to compute scroll size and visible rows. |
orientation | "vertical" | "horizontal" | "vertical" | Scroll axis. Horizontal lists scroll on the inline axis, size the window from the measured viewport width, mirror correctly in right-to-left layouts, and mirror the value to data-orientation. |
overscan | number | 5 | Number of extra rows rendered above and below the visible range so fast scrolling does not reveal blank space. |
estimateRowHeight | (index: number) => number | — | Per-index height estimate that switches the list to dynamic layout, where rendered rows are measured and the estimate is corrected. |
role | "list" | "grid" | "list" | ARIA role applied to the scroll container. |
anchor | "start" | "end" | "start" | Which end of the list the scroll position stays pinned to when items are added or removed. |
followAppend | boolean | "smooth" | false | Scrolls to newly appended items when the list is already at the end, optionally with smooth scrolling. |
scrollRef | Ref<VirtualScrollHandle> | — | Receives the imperative handle exposing scrollToIndex, scrollToOffset and scrollToEnd. |
onRangeChange | (range: VirtualScrollRangeChange) => void | — | Called with the visible and overscanned index ranges whenever the rendered window moves. |
onScrollStateChange | (state: VirtualScrollScrollState) => void | — | Called when scrolling starts and when it settles. |
isScrollingResetDelay | number | 150 | Milliseconds of quiet before scrolling is treated as settled in browsers without the scrollend event. |
className | string | — | Class applied to the scroll container. |
testId | string | — | Value for the scroll container's data-testid attribute. |
Keyboard
| Key | Action |
|---|---|
| Scroll | Wheel, trackpad, or scrollbar moves the window |
| Tab | Move focus between row controls (checkbox, menu trigger) |
| Arrow keys | Rove items inside an open dropdown menu |
| Escape | Close an open dropdown menu |
Accessibility
A full-height spacer keeps the native scrollbar accurate while only a fixed pool of row slots, plus overscan, is mounted; stable slot keys recycle DOM nodes. Rows expose role="listitem" with aria-posinset and aria-setsize inside a role="list" scrollport. Scroll sync is passive, and large jumps such as the scrollbar, Home/End or Cmd+Arrow update the range synchronously.
Styling hooks
data-uiify-virtual-scrolldata-part="spacer"data-part="row"