This is a common question I get asked all the time! Here are some distinctions between the two: Spaghetti sauce has a higher water content. This is why I don't recommend using a jar of marinara when making homemade pizza, you could end up with a mushy watery mess! Pizza sauce is thicker. this goes along with the point above, but pizza sauce contains tomato paste, which causes it to spread easier and more evenly! Pizza sauce is more flavorful. This might be my own opinion, but we like a lot more spices in our pizza sauce than we do in our spaghetti sauce!