Answer: At 5.2 g of net carbs per serving, limes are one of the few keto-compatible fruits.
Each serving of limes (1 fruit, 2" diameter) contains 5.2 g of net carbs. That's a sizeable amount, but limes are still one of the most keto-friendly fruits you can find.
You'll often find limes as part of keto recipes for their juice, which is fairly keto-friendly as well.