Will the biggest pup remain so?

[Elouera]

Just that really. Friends pups were born the same size, except one which is larger. Will they even out as they grow, or always be bigger?

Depends.
One of ours was the fat lump of the litter, but her brothers grew bigger.

@GrumpyMiddleAgedWoman- was it born the biggest?

If the puppy is a pure breed (not a X , or fancy designer breed) then the puppies should be similar in weight & size as adults.

@Elouera, I don't know, but she was the big fat lump at not quite 3 weeks and she was the big fat lump at 8 weeks.

Then her brother grew into the Incredible Hulk while she settled at a very sensible size.

My dog was the Megatron of the litter. He still is at 2yrs 😂

Mine's a cross breed, he was biggest and at a year in is still biggest, nearly twice the size of smallest in litter

Mine was perfectly sized within her litter but bigger than other similar breeds (shes a cross) . Average size now but the big boy in the litter is still a horse!

Mine recently departed dog 1 was a full head larger than his litter mates at birth (humane society puppy), and as a grown dog was a good 15lbs bigger than his female litter mate that we used to hang out with.
It was true for us but no necessarily so for purebreds I’d think.

Mine was second smallest of his litter by a long way. He's now eight weeks and out of the seven pups I'd say he's now the second biggest. His one sibling born smaller than him is still minute at this stage. The breeder told me that size at birth is often no indicator of size at adulthood.

I got a rescue runt of a litter. Believe me he's no runt. He's ended up the biggest of all.

In our case so far yes. Born largest lab, still a puppy at 7 month but still biggest. Although the one that was born smallest, isn’t now the smallest.

Ours was the smallest of the litter when born. 6 months later they are the largest.