There are many ways to reheat pizza. Most of them produce a sad, soggy crust with rubbery cheese. Here are the methods that actually work, ranked from best to still-good.
Best: Cast iron skillet on the stove. Place a cast iron or stainless steel skillet over medium heat. Put the pizza slice in the dry pan and cook for two to three minutes until the bottom crisps up. Add a few drops of water to the pan and immediately cover with a lid for about thirty seconds. The steam re-melts the cheese and heats the toppings without making the crust soggy. Remove the lid, cook another thirty seconds to re-crisp the bottom, and serve.
Second best: Oven at 375. Place slices directly on the oven rack or on a preheated baking sheet. Bake for five to seven minutes. The crust crisps, the cheese melts, and you do not end up with the microwave texture problem. Use a baking sheet if you are worried about cheese dripping onto the heating element.
Avoid: Microwave. The microwave turns pizza crust into a chewy, rubbery mess. If the microwave is your only option, use the lowest power setting and heat in thirty-second intervals. Place a cup of water in the microwave with the pizza to add some moisture. This produces an edible result but not a good one.
Avoid: Air fryer without testing. Air fryers work well for thick-crust and pan pizza but can dry out thin-crust slices. Start at 350 for three minutes and check.