Set inclusive lower and upper bounds, how many numbers you want, and optionally require unique picks. Unique mode shuffles the full range and takes the first N values, so it is safe when N is less than or equal to the number of integers in the range. Large batches are capped for browser performance.
Without unique, each draw is independent in [low, high] (duplicates allowed). With unique, it shuffles the full range (Fisher–Yates) and takes the first count values—so count must be ≤ range size. Count is capped at 500; low ≤ high.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.