TanStack Virtual
Overview
TanStack Virtual is a headless UI utility for virtualizing large lists, grids, and tables. It renders only the visible items in the viewport, dramatically reducing DOM nodes and improving performance for datasets with thousands of rows. Framework adapters are available for React, Vue, Solid, Svelte, Lit, and Angular.
When to use: Rendering thousands of rows or columns, building virtualized tables, implementing infinite scroll, displaying large datasets where DOM node count impacts performance.
When NOT to use: Small lists under ~100 items (no performance benefit), server-rendered static content, layouts where all items must be in the DOM for SEO or accessibility, simple pagination (render one page at a time instead).
Quick Reference
| Pattern | API | Key Points | |||
|---|---|---|---|---|---|
| Vertical list | useVirtualizer({count, getScrollElement, estimateSize}) | Wrap items in absolute-positioned container | |||
| Horizontal list | useVirtualizer({horizontal: true,...}) | Use getTotalSize() for width instead of height | |||
| Grid layout | Row virtualizer + column virtualizer | Two virtualizer instances sharing one scroll element | |||
| Dynamic sizing | ref={virtualizer.measureElement} | Set data-index on each element | |||
| Window scroller | useWindowVirtualizer({count, estimateSize}) | No getScrollElement needed | |||
| Scroll to item | virtualizer.scrollToIndex(index) | Supports `align: 'start' \ | 'center' \ | 'end' \ | 'auto'` |
| Scroll to offset | virtualizer.scrollToOffset(px) | Supports align and behavior: 'smooth' | |||
| Custom keys | getItemKey: (index) => items[index].id | Stable keys improve measurement cache | |||
| Overscan | overscan: 5 | Renders extra items outside viewport (default: 1) | |||
| Gap between items | gap: 8 | Space between virtualized items in pixels | |||
| Multi-lane layout | lanes: 3 | Masonry-style column layouts | |||
| Padding | paddingStart: 100, paddingEnd: 100 | Space before first and after last item | |||
| RTL support | isRtl: true | Right-to-left horizontal scrolling | |||
| Range extractor | rangeExtractor: (range) => [...] | Customize rendered indices (sticky headers, footers) | |||
| Disable virtualizer | enabled: false | Renders nothing, resets internal state | |||
| Force remeasure | virtualizer.measure() | Call after external layout changes |
Common Mistakes
| Mistake | Correct Pattern |
|---|---|
Missing overflow: auto on scroll container | Parent element must have overflow: auto and a fixed height/width |
Using virtualItem.index as React key | Use virtualItem.key which accounts for dynamic reordering |
Forgetting position: relative on inner container | The total-size container must be position: relative |
Not setting data-index with measureElement | Dynamic measurement requires data-index={virtualItem.index} on each element |
Setting estimateSize too small for dynamic items | Overestimate to prevent scroll jumping; use largest expected size |
Recreating getScrollElement on every render | Use a ref callback: () => parentRef.current |
Not using getTotalSize() for container dimensions | Inner container height/width must equal virtualizer.getTotalSize() |
Absolute positioning without transform | Use transform: translateY(item.start) for GPU-accelerated positioning |
Using contain: strict without fixed dimensions | contain: strict requires explicit width and height on the scroll container |
| Using with React Compiler without opting out | Add 'use no memo' directive to components using useVirtualizer — interior mutability breaks memoization |
Delegation
If thetanstack-tableskill is available, delegate data table virtualization to it. TanStack Table has built-in virtualization integration. Otherwise, recommend:npx skills add oakoss/agent-skills --skill tanstack-tableIf thetanstack-queryskill is available, delegate data fetching and infinite query patterns to it. Otherwise, recommend:npx skills add oakoss/agent-skills --skill tanstack-query