Earning decently favorable results across the board in our microwave testing, we wouldn't actively dissuade anyone from purchasing the Panasonic NN-SB458S. It did average or above average across our four performance metrics, and we don't think it's overly expensive in the world of kitchen appliances. This isn't our favorite microwave by any means, with multiple other products considerably outperforming it, but it gets the job done.Editor's Note: This product review was updated on January 11, 2022 with further recommendations and comparison information.
Panasonic NN-SB458S Review
Pros: Good at defrosting meat
Cons: Not the most convenient to use, heating performance could be better
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$119.95 at Amazon
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|Pros||Good at defrosting meat||Excellent with packaged frozen foods, compact, very easy to use||Inexpensive, above-average performance, compact||Easy to use, relatively inexpensive, excellent with prepared frozen items||Good at reheating, does well with premade frozen foods|
|Cons||Not the most convenient to use, heating performance could be better||So-so with mixed leftovers||Low power, Amazon Alexa device required for some functions||Struggled to defrost the ground turkey||Didn't defrost frozen turkey well|
|Bottom Line||This product pairs average results with an average price, failing to stand out from the competition||For those with limited kitchen space, this is the best compact model we tested||This compact model is a great value, offers good performance, and features smart home integration||This product had mixed results overall, failing to distinguish it all that much from other products||This larger product did decently well but we don't think it quite matches the performance of the top-tier models|
|Rating Categories||Panasonic NN-SB458S||Kenmore 70919||Amazon Basics Micro...||Toshiba EM925A5A||Black+Decker EM031MB11|
|Frozen Foods (30%)|
|Ease of use (10%)|
|Specs||Panasonic NN-SB458S||Kenmore 70919||Amazon Basics Micro...||Toshiba EM925A5A||Black+Decker EM031MB11|
|Wattage||900 watts||900 watts||700 watts||900 watts||1000 watts|
|Size||0.9 cu. ft.||0.9 cu. ft.||0.7 cu. ft.||0.9 cu. ft.||1.1 cu. ft.|
|Dimensions||19.1"W x 11.5"H x 14.8"D||17.7"W x 11.0"H x 14.5"D||17.3"W x 10.1"H x 14.1"D||19.2"W x 11.5"H x 15.9"D||20.2"W x 12.1"H x 15.6"D|
|Internal Dimentions||13.9"W x 8.1"H x 12.4"D||13.6"W x 9.3"H x 12.4"D||10.9"W x 6.9"H x 10"D||13.7"W x 8.7"H x 12.3"D||14.5"W x 9.1"H x 13.9"D|
|45 Sec Heating Temp Rise||89 F||83 F||70 F||89 F||83 F|
Our Analysis and Test Results
Though this model delivered one of the best performances of the entire microwave test suite with the frozen burrito and had one of the better popcorn presets, we wouldn't base a purchase decision on those factors alone. However, they might be something to keep in mind if you are considering this particular model.
As mentioned above, the Panasonic NN-SB458S delivered its most noteworthy performances with frozen foods — both with premade frozen foods and when defrosting frozen ground turkey. This kitchen appliance exceptionally impressed us with its performance in the burrito test, with the left, right, and center zones only showing an average temperature difference of only 3°F, with the entire burrito warmed up both above the recommended temperature and warm enough to serve in the opinion of our testers.
It did almost as well with the Hot Pocket, with the average temperature difference only increasing to around 7°F. However, the NN-SB458S lost a few points for slightly burning one end, getting it a little crustier than we would have liked.
The Panasonic NN-SB458S continued its strong showing into the defrosting test. This microwave completely defrosted 8.75 ounces of the one-pound block, and the remaining part very easily broke apart — enough that we would have felt fine to toss everything right into the pan. It had an alert to let us know when it was time to flip the turkey a few minutes into the process, and we appreciated that it didn't cook any of the meat prematurely.
The NN-SB458S performed a bit better than average in some of our heating tests. It heated the 125 mL of water very quickly, raising its temperature to almost 90°F after 45 seconds of heating. It also did exceptionally well with our plate of leftovers using its auto-reheat function. The sausage, potatoes, and green beans weren't too far apart in temperature, and all three were warm enough to eat without additional time in the microwave, something we couldn't say about every model.
The Panasonic NN-SB458S also did an above-average job at reheating the canned soup, getting it more than warm enough when we followed the heating instructions.
The Panasonic NN-SB458S delivered some relatively poor results when it came to reheating pizza. The two slices were heated very unevenly, with one slice being far from hot enough to eat and the other exhibiting significant temperature discrepancies.
We weren't amazingly impressed with this appliance's performance in our heat map tests. Some areas were completely burnt, while others were still browning.
The NN-SB458S also disappointed us somewhat with its performance at heating the individual miniature lasagna. Overall, it wasn't heated quite enough, and there were substantial temperature discrepancies between the six points we measured — one as large as 52°F.
We also found this product to be a little less user-friendly compared to some of the competition. The +30 seconds button doesn't automatically start the appliance, and it lacks any one-touch features. Its internal light isn't terribly bright, and we found that the unit easily slides around when you push a button or open/close the door if it's on any sort of slick countertop.
Should You Buy the Panasonic NN-SB458S?
The Panasonic NN-SB458S provides a decent value as a garden variety microwave offered at a reasonable price. It has a few noteworthy performances (it was stellar with leftovers, although not with leftover pizza), but overall we'd point you in the direction of one of the other better options in the group.
What Other Microwaves Should You Consider?
For a top-of-the-line product that performs well, we'd point just about anyone towards the Toshiba EM131A5C or Kenmore 70919. Anyone intending on mainly cooking frozen foods in their microwave can't go wrong with the Panasonic NN-SN67KS. If you need something for a small kitchen or you have a small budget, check out the Amazon Basics 0.7, which earned respectable scores despite being small and lower-priced.
— David Wise and Austin Palmer
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