Cook time for frozen sausages depends on how you cook them as well as the size and thickness of the sausages. In the oven, sausages will cook in 15-20 minutes. In the air fryer, sausages will cook in 12-14 minutes. In a frying pan or on the grill they will take anywhere from 20 minutes - I do not recommend this option as there's a large risk of burning them. Very large/thick and very small/thin sausages can require more or less time.