TanStack
Virtualized list wrapper keeps stale height after data changes
Describe the bug
Summary
List uses useWindowVirtualizer for row virtualization, but the outer div’s inline
height is read directly from rowVirtualizer.getTotalSize() during render. Because the
virtualizer instance is stable and the getter mutates internal state without changing referential
identity, React never receives a new height value when the rows array is filtered or otherwise
resized. The wrapper therefore preserves an outdated, overly tall height, leaving a large blank
spacer below the visible rows and causing scroll position jumps.
Impact
Any operation that changes the number of rows (search, filters, pagination reset) leaves the list container at its previous height. Users see excessive empty space and the scroll bar no longer reflects the actual result size.
Root Cause
getTotalSize() is invoked inline inside JSX. The virtualizer recomputes its measurement cache,
but React doesn’t detect that the returned string (e.g., "32000px") should change because the
component never re-renders with a different computed value tied to the rows count.
Fix in my case
Memoize the total height using useMemo(() => rowVirtualizer.getTotalSize(), [rowVirtualizer, rows.length]) and pass that memoized number to the style prop. This forces a fresh height
string whenever the virtualizer’s count changes, keeping the spacer in sync. Implemented in commit
Your minimal, reproducible example
https://github.com/kosovatools/kosovatools.org/commit/da4a20196356fd7d96e0fb9b69be9bd662294eeb
Steps to reproduce
.
Expected behavior
Height react to count change
How often does this bug happen?
Every time
Screenshots or Videos
No response
Platform
Firefox
tanstack-virtual version
3.13.12
TypeScript version
5.7.3
Additional context
No response
Terms & Code of Conduct
- [x] I agree to follow this project's Code of Conduct
- [x] I understand that if my bug cannot be reliable reproduced in a debuggable environment, it will probably not be fixed and this issue may even be closed.
