In terms of individual votes, Biden’s ahead by millions… as with HRC in 2016, it won’t even be close. But individual votes don’t matter.
Basically, it comes down to this: if Biden wins Pennsylvania, it’s over. If Biden wins any of Arizona/Georgia/N. Carolina + Nevada, it’s over. But the margin between victory and defeat will be incredibly narrow… probably not Bush v. Gore narrow, but narrow. So he’s technically “ahead”, but that could change in the blink of an eye.