The Panasonic NN-SN686S brings the flagship's inverter technology and Genius Sensor down to a more manageable 1.2 cu ft, 1200W body. Consumer Reports rated it Excellent for both heat evenness and auto-defrost, which arguably makes it the best-heating microwave in this roundup per dish. Buy it if you want Panasonic's even cooking without the 2.2 cu ft model's bulk, and can accept a smaller interior and dated looks.
Full review
Excellent scores for heating and defrost
The NN-SN686S may be the best-heating microwave in this roundup on a per-dish basis. Consumer Reports rated it Excellent for heating evenness in its mashed-potato test and Excellent for auto-defrost in its ground-beef test — top marks in both of the metrics that matter most. That is the payoff of Panasonic's inverter circuit, which holds a true constant power level rather than pulsing, so food heats uniformly and thaws without cooking the edges.
At 1200 watts it is powerful for its 1.2 cu ft size, and the Genius Sensor reads humidity to auto-adjust time and power across its preset menus. MyConsciousEating sums it up as a well-rounded microwave that excels in consistency and ease of use, with the inverter and Genius Sensor setting it apart from competitors. For everyday reheating, cooking, and defrosting, it delivers premium results in a mid-size package.
Capacity and Design
The 1.2 cu ft interior with a 13.4-inch turntable is the practical middle ground: large enough for most dinner plates and everyday dishes, but far less space-hungry than the 2.2 cu ft NN-SN966S. MyConsciousEating notes the unit stays remarkably compact for its capacity, partly because the inverter power supply is physically smaller than a conventional transformer. That efficiency in packaging is a real advantage for kitchens where counter space is tight.
Aesthetically, it is conservative. Reviewed describes it as an all-around-adequate microwave with an old-fashioned look, and the stainless finish with a membrane control panel is functional rather than stylish. Notably, unlike the Toshiba, it lacks a mute function, so the beeps cannot be silenced — a small but real annoyance for some households.
Turbo Defrost without the flagship price
Reviewers consistently praise the NN-SN686S for delivering flagship-grade cooking in a more livable size. Consumer Reports' dual Excellent ratings give it the strongest independent lab credentials in this group, and MyConsciousEating's verdict that it excels in consistency captures why owners trust it for daily use. The Turbo Defrost feature draws particular praise for thawing quickly without the partially-cooked edges that plague conventional microwaves.
For buyers who specifically want even heating — the thing that most distinguishes a good microwave from a mediocre one — the NN-SN686S is the value sweet spot. It costs less than the 2.2 cu ft flagship and takes less room, while giving up nothing on the inverter technology that drives its cooking quality.
Capacity limits it for batch cooking
The main limitation is capacity. As several reviewers note, the 1.2 cu ft interior can feel limiting if you frequently cook or reheat large dishes — a big casserole or oversized bowl that fits the 2.2 cu ft NN-SN966S may not fit here. For most buyers 1.2 cu ft is plenty, but households that batch-cook should size up.
The dated styling and membrane controls are the other knock, and the lack of a mute function is a genuine miss next to the Toshiba's silenceable beeps. It also costs more than conventional microwaves of similar size, so the value proposition depends on caring about inverter even-heating. If you do not, a cheaper conventional model covers basic reheating for less.
Beats the Toshiba on heating evenness
The NN-SN686S is the direct compact alternative to the NN-SN966S: same inverter and Genius Sensor, 1.2 cu ft instead of 2.2, slightly lower 1200W versus 1250W output. Choose it over the flagship if counter space or budget matters and you do not need the larger interior. Against the conventional Toshiba EM131A5C-BS — its closest size rival — the Panasonic wins decisively on heating evenness, while the Toshiba counters with a humidity sensor, mute function, and lower price.
Compared with the budget Black+Decker EM925AB9 and compact Galanz GLCMKZ09BKR09, the NN-SN686S is a clear step up in cooking quality thanks to the inverter, at a correspondingly higher price. It is the pick for the buyer who prioritizes how evenly their food heats above all else.
A smaller alternative to the 2.2 cu ft model
Buy the NN-SN686S if you want Panasonic's class-leading inverter even-heating and excellent defrost but lack the space or budget for the 2.2 cu ft NN-SN966S, and you do not regularly cook oversized dishes. Step up to the flagship if you need the larger interior, or down to the Toshiba if you want a mute function and a humidity sensor for less money and can tolerate slightly less even heating.
Strengths
- +Same inverter even-heating and Genius Sensor as the flagship in a smaller body
- +Excellent Consumer Reports scores for heat evenness and defrosting
- +1.2 cu ft fits most dishes while taking less counter space than the 2.2 model
- +Turbo Defrost thaws quickly without cooking the edges
- +1200W output is powerful for its compact size
Watch-outs
- −Capacity can feel limiting if you frequently cook large dishes
- −Old-fashioned styling and membrane controls
- −Costs more than conventional microwaves of similar size
- −No mute function unlike the Toshiba
How it compares
The compact sibling of the Panasonic NN-SN966S, sharing its inverter and Genius Sensor in a 1.2 cu ft body that matches the Toshiba EM131A5C-BS's footprint. Its inverter even-heating beats the conventional Toshiba EM131A5C-BS, Black+Decker EM925AB9, and Galanz GLCMKZ09BKR09; the only thing it gives up to the NN-SN966S is interior size and a little power.
Rating sources
“The Panasonic NN-SN686S performed Excellent in the heating-evenness test reheating mashed potatoes and Excellent in the auto-defrost test thawing frozen ground beef.”
“The Panasonic NN-SN686S is a well-rounded microwave that excels in consistency and ease of use, with Inverter Technology and Genius Sensor setting it apart from many competitors.”
“An all-around-adequate microwave with an old-fashioned look, equipped with Inverter Technology and a Genius Sensor for even cooking and quick defrosting.”
Our 4.4 score is the average of these published ratings. Ratings marked * were derived from the reviewer’s written analysis or video transcript — the publisher didn’t print an explicit numeric score, so we inferred one from their own words. Click through to verify. More about methodology.
