Answer: Apples are not keto, as they're too high in sugar.
There are a variety of apples, from Red Delicious to Pink Lady, but unfortunately none are very keto-friendly.
Granny Smith apples have the fewest carbs, but one whole apple is still around 18 g of net carbs. Sweeter apples like Red Delicious are even higher, at 25 g net carbs per apple.
For a nice, keto-friendly fruit, consider a delicious avocado.