useWindowVirtualizer with measureElement breaks scroll restoration

[Krasnopir]

Which project does this relate to?

Router

Describe the bug

When using
"@tanstack/react-virtual": "3.13.8"
and
"@tanstack/react-router": "1.112.12"

If the page contains a virtualized list like this:

  const virtualizer = useWindowVirtualizer({
    gap: 16,
    overscan: 4,
    count: data.items.length,
    estimateSize: constant(188),
    scrollMargin: listRef.current?.offsetTop ?? 0,
  });

And the items use:

              ref={virtualizer.measureElement}
              data-index={index}

But the actual element sizes differ from estimateSize, triggering re-measurement on mount — in that case, scrollRestoration breaks.

This might be an issue on the @tanstack/react-router side; I’ll duplicate this issue there as well.

Current workaround: add this option to the virtualizer:

scrollToFn: () => null,

Your Example Website or App

https://codesandbox.io/p/sandbox/2lryyk

Steps to Reproduce the Bug or Issue

1 Open the Home page
2 Scroll down a bit
3 Navigate to the List page
4 You'll notice that the page is not scrolled to the top

In the code, there's a commented line:

in code there are commented string with
scrollToFn: () => null

Uncommenting this line.
After doing that, navigation with scroll restoration works perfectly.

Expected behavior

Virtualizer does not break scroll restoration.

Screenshots or Videos

2025-05-07.15.51.53.mov

Platform

macOS

Additional context

No response

[Krasnopir]

as far as I understand the problem is that the virtualizer tries to keep visible elements in their places and when recalculating the height - it moves the scroll container, in the case of useWindowVirtualizer - the entire body.

And here the question is rather why the value of the previous page is taken as the initial value of the scroll position. At what point does the magic of scroll restoration occur.

[Krasnopir]

Duplicate issue in virtual repo - TanStack/virtual#997