The Ooni Volt 12 and Breville Pizzaiolo are both 12 inch electric pizza ovens designed to be used indoors. However, unlike the Ooni Volt 12 which can reach 850F (450C), the Breville Pizzaiolo can only reach an ambient temperature of 750F (400F). Also, while both pizza ovens are designed to fit a 12 inch pizza, the Breville Pizzaiolo has a round baking surface while the Ooni Volt 12 is square. A square baking surface is larger than a round one and gives more flexibility different pizza shapes as well as various pan styles like Detroit and Sicilian. In terms of price, the Ooni Volt 12 costs $999 while the Breville Pizzaiolo costs $999.95.