Microwaves: How we test microwaves

Which? tests the best-selling microwaves and we also look for newly launched or interesting models, particularly if they have innovative features. Our reviews include basic solo microwaves, microwaves with grills and combination microwaves which offer convection cooking. And we test both freestanding and built-in microwaves.

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Check out our video to see why a Best Buy microwave will make a real, practical difference to you.


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Microwave heating test

We test microwave heating with a specially made substance which has a similar consistency to a lasagne when heated in a microwave. We heat the test-food on full-power and record how evenly the microwave heats it up, whether all parts reach a safe temperature and whether it dries the food out. The best microwaves heat food quickly and evenly without drying it out. The worst take far too long to heat food up, don’t get food hot enough and leave it shrivelled.

Microwave defrosting test

We use slabs of lean, minced beef which has been frozen for 12 hours and set the microwaves to defrost according to the user instructions. We record the highest and lowest temperatures and check for hot or cold spots in the meat. We also defrost frozen mince using pre-set auto-defrost programs where available. The best microwaves defrost meat evenly, the worst cook some parts while leaving other parts still frozen.

Microwave grill test

We test how well grill elements in grill and combination microwaves work by covering the grill rack with white, crustless bread and then measuring the spread and evenness of the heating. The best grill microwaves will evenly spread heat to more than 90% of the bread. The worst hardly brown any of the bread at all.

Microwave baking test

We test how well the convection function on combination microwaves works by baking trays of cakes. The best combination microwaves will produce well risen, evenly browned cakes. The worst will burn the cakes, or leave them uncooked.

Microwave ease of use test

We assess how easy it is to set microwaves and to carry out simple tasks such as opening the door and cleaning them. The best microwaves are very easy to use and are intuitive to set. For the worst microwaves you’ll need to keep the instruction manual to hand.

If you have difficulty with strength or dexterity in your hands, take a look at our selection of the easiest to use microwaves, which includes advice on that to look out for.

Microwave noise test

We record microwave noise when heating on full-power and when defrosting. The quietest  microwaves make about 47dB of noise in microwave mode. The noisiest make 62dB - this will sound three times louder.

Microwave safety tests

We test microwaves for electrical safety and microwave leakage. We also check if they can be damaged if you accidentally turn them on without food inside them and whether they can safely contain flames caused from sparking if metal items are put in by mistake.

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