800W microwaves are microwave ovens that have a power output of 800 watts. This power level is used to determine the cooking speed of the microwave. Generally, the higher the power output, the faster the food will cook. 800W is a common power output for home microwave ovens and is suitable for most cooking and reheating tasks. However, compared to a 900W microwave, an 800W microwave may take slightly longer to cook food.