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Microwave Ovens with Inverter Technology Really Cook
Updated 3/3/2024 with improved chart, market information, and recommended models.
If you’re like most consumers, your microwave oven serves two main duties: boiling water and reheating leftovers. But wouldn’t it be great if rather than just taking up a chunk of space in your kitchen, you could actually rely on your microwave for cooking meals?
Cooking food successfully in a microwave is challenging because the magnetron, the element that cooks the food in most microwaves, can only deliver full power. Even when set to “50% power”, the microwave oven is going through cycles of delivering 100% power, followed by a period of no power.
Imagine if your regular oven worked this way. Instead of cooking a roast at 350 degrees, you’d cook it at 700 degrees for ten minutes, then take it out for ten minutes, and repeat over and over again until the meat is cooked. Good luck with that!
The microwave inverter solution
Originally developed by Panasonic, there are now multiple brands on the market offering “inverter” technology, which aims to solve this problem. The inverter modulates the level of energy being transmitted by the oven to achieve a consistent level. So when you set 50% power, for example, you get a steady stream of 50% power for the entire cooking time. The result is more evenly cooked food, defrosting without cooked edges, and even the ability to keep foods warm until mealtime.
I spent weeks testing Panasonic inverter microwave ovens. Using recipes from Panasonic, including some produced by the prestigious Culinary Institute of America specifically for inverter microwaves, I made hollandaise sauce, fruit crisp, corn chowder, barbecued pulled pork, and other fun dishes.
What I found was that the microwave inverter performed surprisingly well for dishes that required slow cooking in moist environments, such as the hollandaise sauce (which can be tricky to do on the stovetop) and pulled pork. Corn chowder worked fine as well, though it would have been just as easy on the stovetop and we didn’t like moving large bowls of boiling liquid in and out of the oven. Perhaps not surprisingly, the fruit crisp was a flop, with a soggy, raw-tasting topping and overcooked fruit underneath. However, this could be fixed by finishing it in your oven or air fryer.
Final take on inverter technology
Based on my experiences, I could easily see using an inverter microwave in addition to my standard cooktop and range, especially during busy holiday times when I am trying to cook many dishes at once, while also keeping everything warm until serving time. It is a fast and clean way to steam vegetables, melt chocolate, braise meats, or do any one of a number of occasional kitchen tasks that involve steady cooking and do not require browning.
Recommend models
If you are purchasing a microwave, I strongly recommend considering an inverter model. Various options are offered by Breville, Cuisinart, LG, Panasonic, Sharp, and Toshiba, among others. As the originator of inverter technology, Panasonic has been in the game for decades. They offer models to fit pretty much every space and budget. However, you’ll get a little more bang for your buck with Toshiba.
Panasonic NN-SN936B: Best full-size inverter microwave
The Panasonic NN-SN936B excels in even cooking, user-friendliness, and power. With 1250W of power and a sizeable 2.2 cubic foot capacity, it’s perfect for families. Turbo Defrost and the Genius Sensor help to heat quickly, while avoiding overcooking. And 14 one-touch cooking options for popular items like popcorn, potatoes, and more, keep operation simple.
While I haven’t tested this model directly, it has the exact same inverter technology and features as the discontinued models I reviewed previously.
Specifications
- Capacity: 2.2 cubic feet
- Wattage: 1250 watts
- Turntable: 16.5 inches
- Dimensions: 23⅞" W x 14" H x 19 7/16" D
- Finish: Black or White
Panasonic NN-SN686S: Best compact inverter microwave
The Panasonic NN-SN686S is an excellent choice for those seeking a reliable, mid-sized microwave featuring the precision of Inverter Technology. If you have limited counter space or don't typically cook for larger groups, this model offers all the key benefits of the NN-SN936B in a more compact package.
Specifications
- Capacity: 1.2 cubic feet
- Wattage: 1200 watts
- Turntable: 13.4 inches
- Dimensions: 20.7" W x 12.2" H x 15.8" D
- Finish: Stainless Steel
Toshiba ML-EM45PIT(BS): Best value inverter microwave
The Toshiba ML-EM45PIT(BS) is an excellent choice if you're looking for maximum bang for your buck. It offers a larger capacity (1.6 cubic feet) and slightly more power (1250 watts) compared to the Panasonic NN-SN686, while maintaining a very similar price point. A Smart Sensor adjusts power levels and cooking times automatically based on the food's moisture (similar to Panasonic's Genius Sensor), while 6 preset auto cook options cover the basics.
Specifications
- Capacity: 1.6 cubic feet
- Wattage: 1250 watts
- Turntable: 13.6 inches
- Dimensions: 21.8" W x 13" H x 19.2" D
- Finish: Black Stainless Steel
Discussion 
The Panasonic inverter technology is about the power supply. Instead of a heavy transformer-based power supply (providing a single setting of power), the Panasonic uses an inverter which can provide multiple levels of power to the microwave generator (the magnetron). The inverter is smaller and weighs less, so Panasonic benefits from more interior per exterior size and lighter weight (by a noticeable amount).
Thank You for the informative artical explaining Inverter Technology. Although the artical is several years old, the information is still relevant.
As more and more manufactures are using the technology. I just purchased a Frigidaire 1.6-cuft 1.100 watt. Counter top model FFMO1611LB At Lowe’s.
Hi Ollie,
Glad you found the article useful. I looked through Frigidaire’s site and I don’t see anything that would suggest they are using inverters in their microwaves. Did you see something that suggests otherwise?
Best,
Josh
This is the link to Lowe’s listing for the
Frigidaire Model FFMO1611LB
http://www.lowes.com/pd_425512-2251-FFMO1611LB___?productId=50059337&pl=1&Ntt=frigidaire+microwaves
I can’t find any references to any Frigidaire models using ever using inverter technology. I called Frigidaire technical support and they confirmed that no Frigidaire models use an inverter.
However, the model you listed is a pretty old model and it’s possible they may have had it at some point. It should be easy enough to tell when running it. With normal microwaves, if you set it for 30% power, you will hear the magnetron cycle on and off every 15 seconds or so. With an inverter, there will be no cycling, power will be continuous.
Give it a test and let me know what you discover.
Thanks for your research, I canceled the order at Lowe’s, because the oven did not have the Inverter Technology and the long delivery time.
Went to Amazon, looked up Panasonic and placed an order for a NN-SN733B.
1250 watt’s 1.6 cu.ft.
At 1250 watt’s this is the highest powered I have seen for a 1.6 cu ft microwave oven.
I bought my Panasonic inverter MW from Amazon. They have a 48 hour return policy. You have to get it unpacked, try it out and decide all within 48 hours. From reading these reviews I see it is possible that mine was a dud. Read my review. I’m not going to go without a microwave for two weeks and I’m not going to drive to another state to return it. The problem really is with Panasonic. I’m going to buy local - and not a Panasonic!!
Calories[or Watts!]: energy required to raise the temperature of some Water by some Degrees during some Time.
Measure out 1 quart of Water, and measure the Temperature.
Microwave the Water for One Minute at Power setting 1.
Measure the Temperature of the Water again, and note the change in Temperature.
With fresh water, do the same for Power Setting 2, measure the change in Temperature after One Minute.
Once you have this list of temperature changes for each power setting, find the formula that tells you how many Watts it takes to heat up a quart in sixty seconds by the temperature-changes on your list.
This sort of calibration seems crude, but it is a good measure of how much energy your oven actually delivers into water in a minute at each setting. Microwaves do most of the cooking through the heating of water/moisture.
I am being lazy, not providing equation.
I do agree, a direct wattage setting would be very handy, and be a reliable standard.
“Warm for 5 minutes at 18 Watts/second” would be nice….
Why, out of the dozens & dozens of co’s making micro-waves, doesn’t at least one make a left hand door model?
Hi Josh,
I am buying new microwave. The Cyclonic wave sounds interesting. Have you evaluated it and if so, how does it compare to one with only the inverter tech?
The cyclonic microwaves use the same inverter cooking mechanics as all the other Panasonic microwaves. The difference is that the cyclonic models claim to distribute the microwaves more evenly within the interior, for more even cooking.
I haven’t tested the cyclonic microwaves side-by-side with the non-cyclonic. If the price difference is relatively small, I would probably opt for the cyclonic model, though either would be a step up from a non-inverter oven.
I don’t think it makes sense to specify a particular wattage because this only applies while the microwave is new. As the magnetron ages with use, its effective power decreases. It might make sense if the decline is predictable and the oven takes this decline into account when displaying the power.
just replaced old GE Microwave with a new Profile GE. It was great to be able to adjust the wattage. It seems more logical having this ability to raise or lower its strength just as we control our stovetop or oven gas or electric. I am getting the hang easily enough of reheating items that once were problems with chicken or certain meats. Getting closer to the “Jetson’s” technology. Cool!
I agree these manufactures need to own up to their products!Along with your “call” I think they should also stop charging outrageous prices for the replacement parts for ANY devices period! WTH good is paying 250 for a MW then the board goes out and the cost for the damn board is 225 when the damn whole MW is only 250…So tired of all this over priced replacement parts BS, if they could make an sell the MW for 250 then they should be forced to divide that 250 up when putting costs on replacement parts!Its no wonder humans waste so damn much, WHY pay 225 for a board for something that you bought BRAND NEW for only 250. Then they got that who “black market” used parts BS where the used part is 215 WTF is wrong with humans and their GREED…If our government should put their nose in things put it in this not healthcare!
Electricq now offer an inverter microwave oven in the UK. the model no is:- EIQMW9BEAINV. It is available from Buy It Direct who are the importers and Tesco.
I am in Spain. I purchased a Panasonic NN DF383 1000W inverter microwave oven, combined with convection + conventional oven.
The inverter part failed after a month of use, had some smoke inside, bad smell and no heating. I took it to the Panasonic Service and got the inverter circuit replaced.
Back home I noticed now it takes much longer to heat food than when new. Made a quick test of power with a measured quantity of water and noting the temperature increase in five minutes and got a result of about 740W instead of the intended 1000W.
A measure of the input power shows normal input power of about 1750W, but it decreases slowly during operation and is only 1300W after 5 minutes heating.
I suspect the Magnetron is defective. I will take it again to Service, but son far it has been a bad and frustrating experience.
Good day
I am owning a Panasonic Micro oven and the service provider indicated that an Inventor(A606Y4V00GP) need to be replaced.
Contact details: 072 280 3725
Advise please.
I want a microwave that bakes, heats through evenly and does small roasts. Should i be looking at inverter or convection model?
While an inverter will heat evenly, it will not brown roasts or bake the way a regular over will. For that, you definitely want a convection oven. Some microwaves have convection cooking, as well, or you could get a large toaster oven that offers convection cooking. Our recommendation for the best large toaster can be found here: https://www.techlicious.com/review/best-toaster-oven/
Manufacturers are more interested in the latest bells and whistles than being practical. We need a white (for visually impaired) oven, no sensor cooking, and one that could make it through year one. We are on our third one with the same warranty, Kenmore from Sears.
Some manufacturer specifies the MO as 1000W microwave power output, (as written on the plate). But the line Input power is given as 1040W on the same plate. Does it mean that the inverter + magnetron has an astonishing high 96% efficiency?
Not really,they make a biased interpretation of IEC 60705, the Norm to measure the power output of microwave ovens.
We already know the trick: design and specify a product that complies, but only while at the Test Bench… same as certain German diesel engines!
So, this inverter type MO will provide the 1000W output, but only for very few minutes. The time necessary to test according to IEC 60705. After that, they gradually reduce the output power to about 600W. That is what you actually get if you cook for, say, 15 minutes.
Easy to prove: measure the input power and you get initially about 1720W (reasonable for an output of 1000W, efficiency 60%). Continue for 5, 10, 15 minutes and you will see the input power descending to 1050 W - and 600W aoutput power!
And this is legal, they comply with IEC 60705. But you only have 600W instead of 1000!!!
A nice, but very indecent trick, absolutely unmoral that this Japanese manufacturer is using to cheat its trusting customers.
Where do I get a replacement for a broken latch.
model#NN-SN936B OR 946B OR 736B
The door latch issue on Panasonic microwaves can sometimes be repaired yourself. Do a Google search on “Panasonic microwave door latch repair” and you’ll see a number of videos showing you how to do it. If it truly is broken, you should contact a Panasonic authorized repair center to get it fixed. They may be able to sell you the part but, more likely, will require you to have them repair it (at a cost that probably won’t be worth it).
I’m in the market for a new microwave now. What are your updated recommendations?
Hi Pam,
Not much has changed in the microwave market over the past five years. The Panasonic SD-945S is our top pick in our Best Microwave Oven article. Read the story for more detail on why we recommend that microwave over others, including the latest Panasonic “cyclonic” models.
Best,
Josh
Hi,
I’m looking for a gift for my kids - they are living in an extremely small place & their oven is a mess. I’m looking for a microwave oven that will cook (obviously minus burners) like a REAL OVEN -
I’m looking for counter top & something they can take along when they buy a house in the future - so,
something that cooks great & looks great & can be used when they move ..
There are a few models of countertop oven out there that combine a microwave with a convection oven. Cuisinart, Kenmore and Kitchenaid are some of the options (e.g., http://amzn.to/2AmKGF3). I haven’t tested any of them and, ideally, they would get better results from a separate microwave and oven, but if space is really tight one of these might work.
Back in the 70s & 80s, we had two Amana Radarange microwave ovens which had a system that controlled the pulse timing of the power levels to offer very even cooking. !00% magnatron power was always utilized, but the rapid on-off cycling provided even heat production. On power level “1” the “ON” pulse might have been only one second followed by maybe ten seconds OFF. The rapid cycling of the Radarange did not over cook the edges of food, melted butter eveningly, cooked roasts and whole chickens thoroughly inside and out. If I thought for a minute this new inverter technology even closely compared to the results provide by a 40 year old Radarange, I’d have one in a second. Yes, we are still using both Radaranges. One magnatron replaced in 40 years. Not bad, right? I only wish Amana still made them with newer external designs.
“On power level “1” the “ON” pulse might have been only one second followed by maybe ten seconds OFF”
Microwaves still work the same today.
Non-inverter ovens (nearly all except Panasonic) work that way, by pulsing the magnetron on and off. For example, lowest power (10%) would be full power “on” for 1 second, then “off” for 9 seconds. 50% power would be on for 5 seconds, then off for 5 seconds, etc. That’s like putting a fry pan on a high burner for a few seconds, then removing it , then putting back on, etc. to reduce the heat. This is far different from reducing the energy output of the magnetron as an inverter oven does. An inverter oven is like a gas burner which can be turned to low flame, high flame, or anywhere in-between. This offers far more even, uniform, more consistent heat than pulsing between high heat and no heat.
Hi I just purchased the Panasonic NN-SF574S microwave because of flatbed and inverter features. We are old school and have never had a microwave before. It fits in a cavity in our kitchen however the manual specifies 15cm airflow on top we have 4cm! We do have the suggested 10cm at back and 5cm on each side…What are the likely consequences of having too little airflow on top? Should I return it?
That’s tight, but probably tolerable - unless it’s also convection, which heats the entire oven - not just the food itself. Try it heating water or something for 15 minutes and periodically feel the top. If it’s slightly warm, that’s good. If it’s definitely hot, that’s not.
I use the standard oven mode (convection) regularly in my Panasonic 1Kw Microwave.
It gets quite hot everywhere, including of course the top of it. I think it would not work OK with only 4 cm ventilation space on the top, if you use convection in your model.
Not only you may burn something, but also the internal electronics could be damaged, even if not all of it is operating in convection mode. Timer and display always operate and should no be overheated.
Actually
your regular oven DOES work that way. The heating element only has two settings: On or off. Once it achieves the desired temperature it cycles off/on/off/on/off/on et cetera. So that’s just like a microwave that cycles off/on/off/on et cetera.
There’s no difference from an engineering point of view.
Yes, your oven does have a heating element that cycles on and off. However, your oven doesn’t go from room temperature to 500 degrees every time it cycles. The oven will have some variation in temperature, maybe 5-10 degrees between cycles, but that’s it - your food will be cooking consistently at (close to) the temperature you set.
The microwave will cycle between full blast power and no power. And during that full blast cycle, it’s very easy to overcook your food before you even realize it, especially for more delicate dishes.
I regularly cook in my microwave. Mostly I do steaks and other meats, converting them from raw to medium rare. They are delicious.
I have also cooked mac’n'cheese and other sauce-immersed items.
Setting the microwave to 20% or 30% gradually raises the food’s temperature and cooks it, in much the same way a slow cooker does. (Except the microwave does it in 30 minutes instead of 4 hours.)
Hi ! I bought the Panasonic Cyclonic Inverter (NN-ST775S) 18 months ago. I have a problem with it. Sometimes, the micro-wave stop after 4 secondes of reheat. After 4 secondes, i heard the sound inside change for lower sound. And then, everything is alright or everything stop and i lost the timer and the hour and i have to reset et reprogram. Somebody know what is the problem ? Thanks.
Inverter are not made to rush such power into the high Voltage DC Diode to graduate the magnitude flux into the magnetron
increasing or decreasing the voltage wattage without loosing the performance of the magnetron… depending on the size of the cooking plate 750W per inch square will be fair to start cooking and auto-transformer will do best to drive and performed those task… unless if the inverter are made in the better quality
I have read that the new way to pack more space into a microwave oven is to remove its turntable as its inverter technology uses actual power reduction rather than a duty cycle change to manage the cooking rate. Does this mean that Flatbed microwaves are simply inverter microwaves without the turntable ?
If this is so, can’t we achieve the same space by removing the turntable in our microwave and replacing it with a low profile rectangular pad with a hole in the centre to accomodate the central spindle just below the plate’s surface ?
I mean ... wouldn’t this carefully constructed microwave safe plate allow more room inside an inverter microwave without the flatbed upgrade. Granted the microwave external size is a little bigger due to its now defunct turntable drive but, if the inverter allows for more space for rather big dishes, It seems to me an accessory rectangular mat or plate that accommodates the spindle is a terrific way to get even more out of a conventional inverter turntable microwave.
The turntable is there to evenly distribute the microwaves around the food, which doesn’t happen very efficiently inside a rectangular box. Removing the turntable will result in less even heating. This is independent of whether a microwave has an inverter or not - the distribution of microwaves inside the oven is no different, they just can be generated at varying power.
I suspect the reasons why some ovens are made without a turntable are either to reduce cost (for smaller, cheaper microwaves) or to increase durability (for commercial use applications).
Something new (to me) has been added. Some MW ovens are now made with a different magnetron configuration and do not come with a turntable. It seems they are called FLATBED ovens. I copied this—- “With microwave ovens that use flatbed technology, the microwaves are emitted from a rotating antenna located underneath the ceramic base of your microwave oven.”
Now, what I would like to see is a MW with a rotating antenna AND a turntable. Maybe THAT would finally eliminate hot spots (and cold spots). 
I believe this “remove turntable” idea is just ANOTHER bad idea circulating on the Internet. If I am wrong (and I could be), please supply some kind of proof. Anyway, microwave ovens and magnetrons are not perfect. They DO NOT distribute the energy in a perfectly even pattern. The turntable is there to move the food through the ‘uneven’ pattern of microwave energy, helping to get all the food a more ‘average’ amount of energy during a cooking cycle. Whether a particular oven has an inverter or not does not affect the ‘pattern’ of energy within the microwave. It will, unfortunately, still be ‘uneven’, thus STILL requiring that the food be moved around through the energy field while cooking for more even energy distribution. If you want to see for yourself, try putting slices of buttered bread over the entire bottom of the oven without the turntable and see how evenly the bread is heated. Then do it again using the turntable, using as much bread as will fit and rotate. Do this several times at different power levels. Compare the results and decide whether you want to use the turntable or not. You don’t have to depend on other people—DO YOUR OWN TESTING, THEN MAKE A DECISION.
Sorry everybody, I just realized I was not very clear in my post about removing the turntable in a microwave oven.
I was speaking of REMOVING THE TURNTABLE and using the oven without it. My opinion on that still stands.
As far as microwave ovens that DO NOT COME WITH A TURNTABLE, the magnetron that creates the microwaves is designed and positioned differently to work without the need for a turntable. That is a totally different design, so, obviously, it is OK that they do not use a turntable. As to how well they work—I honestly don’t know (never having used one).
Hi,
It seems that commercial kitchens use flatbeds to limit the chance of a glass turntable creating problems by breaking due to the very high use they get. I’m also aware now that these use ‘stirrers’ which direct the microwaves more evenly throughout the cabinet than a domestic microwave. Thus no turntable is needed, giving more room and more safety for high use. I do not know if these ‘stirrers’ are rotating fins or carefully positioned reflecting surfaces or well… both, but because more care is taken to evenly distribute the microwaves, the obvious advantage is a more accessible cavity and less glass breakage risk.
Of course if the ‘stirrer’ is accompanied by a turntable anyway, this must surely be the best way to get an evenly cooked/heated end result.
So… we can’t just remove the turntable as I thought we could, because the distribution of microwaves in a domestic with turntable lacks a ‘stirrer’. I’m quoting the ‘stirrer’ from another site… quora actually.
Just ordered a Toshiba microwave with inverter technology. Not sure if I made the right choice? Any reassurance would be appreciated!
From Mellie Mel on May 26, 2015 :: 12:08 pm
I just got a 2010 Panasonic (NN-SN797S) for free from a friend to replace an 2009 Oster microwave that had inexplicably stopped heating last weekend. Thanks for explaining the inverter technology, that’s exactly what I came here to find out. One thing that struck me about the Panasonic is that it is much lighter despite being bigger and more powerful. Makes me suspicious of the build quality (more plastic?).
I’m also impressed that you’re keeping this entry up to date 6 years after writing it. Thanks again.
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From Josh Kirschner on May 26, 2015 :: 5:08 pm
Wow, I didn’t realize it had been that long until you pointed it out…A lot of people come to this article to learn about the inverters, and 90% of it is still as relevant as the day I wrote it, so I try to keep that other 10% current.
I’m afraid I’m not enough of an expert in microwave internal parts to answer your question about the weight, though. If i had to guess, I would assume that it’s the heating components (magnetron, power supply, something else) that weighs less for inverter ovens, rather than being more plastic.
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