You have a list of a million rows and you want to jump to row 842,013. ScrollController.jumpTo takes a pixel offset, not an index. To convert one to the other you need the total height of the 842,012 rows above your target — and a lazy list has never built them, so it does not know how tall they are. That is not an oversight. It is the entire point of a lazy list. Flutter ships no answer. The two packages that did are both dead: scrollable_positioned_list — archived by Goo...