A vacuum sealer has one job: pull the air out of a bag and close it before any gets back in. Everything that follows from that — a steak that keeps months rather than weeks in the freezer, a sous vide bag that sinks instead of bobbing, a Sunday batch that still tastes like food on Thursday — depends on how much air comes out and whether the seal holds. So there is really only one specification that matters, and this is the rare category that publishes it in two incompatible units — or, far more often, not at all.
Nesco states 25.1 inches of mercury. Inkbird states minus 80 kilopascals. Anova publishes an extraction rate in liters per minute and no pressure figure at all. FoodSaver, Avid Armor and Zwilling publish no suction number in any unit. That is not several kinds of rigor; it is one measurement in a handful of costumes, and a buyer comparing listings side by side has no way to line them up. So the first thing this page does is the arithmetic: everything converted into kilopascals, against the 101.3 kPa of atmospheric pressure at sea level, so you can read each claim as a share of a perfect vacuum rather than as a big number.
We ranked on four things, in this order. What happens when the food is wet, because that is where every external sealer struggles and the whole reason chamber machines exist — a marinade pulled toward the pump ends up in the seal, and a seal with liquid in it is not a seal. The suction figure, converted, and whether the maker publishes one at all. Which bags you are allowed to use, which is the single biggest cost decision here and the one nobody foregrounds: one machine on this page is documented as working with any brand, one tells you in its own manual to use only its own, and one works with nothing but its maker's valves. And what the maker publishes and warrants, because on a machine that is a pump, a heating strip and a gasket, the warranty is the closest thing to a durability claim you can hold anyone to.
A note on what we are not claiming. We have not lab-tested these machines and we have no way to verify a suction figure ourselves; what we can do is read what each manufacturer publishes, convert it, say plainly who publishes nothing, and pull the prices live and date-stamped on every card. The honest caveat on the whole exercise is that no maker here states where its figure was measured — at the pump port with nothing attached, or inside a loaded bag — and those are very different numbers.
And one thing worth knowing before you spend anything. A vacuum sealer is not a preservation method. FoodSaver says so in its own manual, in capitals, and two university extension services say it more bluntly than we would dare to: removing the oxygen helps some of the bacteria you least want. There is a section on that below the picks, along with the four common foods the manuals tell you never to seal, and it is the part of this page we would most like you to read.
Three units, one measurement, and most makers publish none of them
Suction is a pressure, and pressure has a ceiling. At sea level the air is pressing on everything at about 101.3 kilopascals, which is the same thing as 29.92 inches of mercury, so no pump can remove more than that and every claim is really a share of it. NIST's own conversion tables put one inch of mercury at 3,386.389 pascals, which is all the arithmetic anyone needs to make these listings comparable.
Run it across this page and the field shrinks to two numbers. Nesco's 25.1 inches of mercury is about 85 kilopascals, or roughly 84 percent of a perfect vacuum. Inkbird's minus 80 kilopascals is about 23.6 inches of mercury, or roughly 79 percent. Those two are close enough that neither is a reason to choose between them. And then there is everyone else: Anova, FoodSaver, Avid Armor and Zwilling publish no pressure figure at all, which includes the most expensive machine on this page and the brand that invented the category in most people's kitchens.
Two honest caveats, because the conversion is cleaner than the underlying data. First, nobody states where the figure was taken. A pump sealed to a gauge with nothing attached will post a much better number than the same pump pulling against a bag, a gasket and a wet chicken breast, and no maker here tells you which test produced its figure. Second, past a certain point more suction stops mattering: once the bag is tight against the food the remaining air is a rounding error, and what decides whether your steak survives six months is the integrity of the seal, not the last two percent of vacuum. We apply the same skepticism to published figures in the sous vide roundup, where every maker now claims a tenth of a degree and the specification has stopped telling you anything.
Flow rate is a different question, and only one maker answers it
Pressure tells you how tight the bag ends up. Flow rate tells you how long you stand there waiting. They are independent, and a machine can be good at one and mediocre at the other. Anova is the only brand here that publishes a flow figure — 12 liters a minute of extraction — and nobody on this page publishes both numbers, which means there is no machine in this field you can fully characterize from its own specification sheet.
Wattage is the usual stand-in and it is a weak one. The Nesco is listed at 130 watts and the Anova at 110, and that difference tells you almost nothing, because the pump design, the chamber volume and the gasket all sit between the motor and the result. We would rather a maker published a flow rate and a pressure and let us do the dividing, which is the same argument we make about watts per quart in the frozen-food air fryer picks and watts per slot in the toaster roundup.
Liquids are the problem this category is built around
An external sealer works by sucking air out through the open end of a bag. If there is free liquid in that bag, some of it comes along for the ride, lands in the sealing channel, and turns into a seal with a wet stripe through it — which is to say, no seal at all, and often a little liquid in the pump. Every machine above answers this in one of three ways.
A moist settingis the cheap answer: less aggressive suction and a longer or doubled seal, which buys you a margin on a marinade rather than solving anything. Nesco publishes a double heat seal as a separate third mode; Anova publishes a double sealer and a moist setting; FoodSaver's manual documents dry and moist settings and a seal button you can hit early. A chamber is the real answer. The Avid Armor does not pull air out of the bag at all — it removes the air from the whole box the bag is lying in, so the pressure above the soup and the pressure in the soup come down together and nothing is dragged anywhere. That is why it is the only machine here we would put a bag of stock into, and why its 15-to-60-second adjustable vacuum time exists: at low enough pressure a warm liquid will start to bubble, and the control lets you stop before it does. And then there is the freezer trick, which costs nothing: freeze the portion flat on a tray first, then seal the solid block. An external sealer handles frozen stew perfectly well, because frozen stew is not a liquid.
The bag is the real product, and the real running cost
Every one of these machines is sold once and then sells you plastic for years, so the consumable question deserves more weight than listings give it. External heat sealers need embossed or channeled bags — the texture is what gives the air a path out once the bag is pressed flat — while a chamber machine takes plain smooth pouches, which is why bag stashes do not transfer between the two formats. That incompatibility is published plainly on the pouches themselves: chamber pouch listings carry explicit notes that they are not compatible with FoodSaver-type sealers.
Then there is who you are allowed to buy from, and here the four machines diverge completely. The Nesco listing states compatibility with any brand of vacuum sealer bag. FoodSaver's own manual says to use only FoodSaver bags, rolls, containers and accessories. Inkbird sells its own and states no exclusion. Anova publishes nothing either way. Zwilling's pump fits Fresh & Save valves and nothing else, which is the tightest tie of all, though its bags are reusable so the comparison is not quite like for like. On price per bag, pre-cut pouches bought in boxes of a hundred or more generally work out cheaper per bag than cutting your own from a roll, while a roll is the only way to make a bag the length of a whole fillet. Neither is wrong; they are different habits.
What it costs to run: the electricity is free, the plastic is not
A vacuum sealer runs for seconds, so the power bill is a rounding error. Take the thirstiest external machine here at 130 watts and give it a generous 30-second cycle: that is about 0.001 kilowatt-hours, so at the US average residential rate we use throughout this site, one hundred seals cost under two cents of electricity. You can check that against your own rate in our running-cost calculator, but the conclusion will not move: there is no energy-efficiency argument to be had in this category, which makes it the exception on a site that usually finds one. We lay out where the real numbers are across the counter in the most energy-efficient kitchen appliances.
The actual running cost is bags, and it is worth doing your own arithmetic before you buy. A household sealing a few portions a week goes through a roll in a season; a household that buys meat in bulk twice a year goes through boxes. That is the number that should decide whether you pay more for a machine documented to take anyone's bags, and it is the reason the Nesco's one-line compatibility statement earns it a place above machines we otherwise rate more highly.
What a vacuum sealer does not do — and four foods the manuals say never to seal
This is the section we would keep if we had to delete the rest of the page. Removing the oxygen from a bag slows the spoilage you can see — the surface drying, the freezer burn, the oxidizing fat. It does nothing about the organisms that prefer no oxygen at all, and some of those are the ones that matter most.
FoodSaver publishes the warning itself, in the FM2100 owner's manual: “Vacuum sealing is NOT a substitute for the heat process of canning. Perishables still need to be refrigerated or frozen.” The same manual carries two blunt exclusions, both attributed to anaerobic bacteria: “Fresh mushrooms, onions and garlic should never be vacuum sealed” and “Soft cheeses should never be vacuum sealed.” It also tells you to blanch vegetables before sealing them. Four common foods, named by the biggest brand in the category, in the box — and we have never seen them mentioned in a roundup.
Two university extension services go further. Utah State University Extension states that vacuum packaging “is NOT a food preservation method by itself” and that it “will increase the ability of the botulism bacteria to grow by removing oxygen,” adding that food which needed refrigeration before sealing still needs it after. Diane Wright Hirsch, writing for UConn Extension, is more specific about the storage rule: “Perishable foods packed in a vacuum package must be refrigerated between 34 and 38°F or frozen at 0°F. They cannot be safely stored at room temperature.” She also makes the point that should decide how you treat the whole category — botulism is most likely in low-acid, moist foods sealed without air, and the food can look, smell and taste perfectly fine while it happens.
So the rule we would write on the lid: a vacuum sealer is a storage tool, not a preservation tool. Seal it, then put it where it was going to go anyway — the fridge or the freezer — and it will last longer there than it would have in a zip bag. Nothing about the vacuum moves anything out of the fridge and onto a shelf. If you want shelf-stable, that is canning or drying, and the food dehydrator roundup covers the drying route, including the USDA pre-heat rule for jerky that no dehydrator can perform for you.
Where the plastic sits, for readers from the materials pages
A large share of this site's readers arrive from the coatings questions — whether air fryers are toxic, where the plastic in a kitchen actually is — and a vacuum sealer puts that question in a sharper form than an air fryer ever does. With an air fryer, food sits on a coated basket for twenty minutes. With a sealer, food sits sealed against a plastic film for months, and in sous vide it sits against that film in warm water for hours. That is the argument we made from the other side in the sous vide roundup: the bag, not the basket, is where plastic, heat and moisture actually meet.
What the makers publish here is thinner than we would like. Zwilling states its reusable bags are BPA-free and sells the system around borosilicate glass containers, which is the only option on this page where the food can avoid film altogether. Bag brands commonly publish BPA-free claims on their listings, including the chamber pouches and rolls sold alongside these machines. None of the machine makers publishes the polymer stack in its own bags, which is why we will not tell you one brand's film is safer than another's. If the question bothers you, the honest options are glass containers for the fridge and short, cool sous vide cooks rather than long hot ones — and if it bothers you a lot, the Zwilling set exists for exactly that reason.
Do you actually need one?
Four cases where our answer is no. If your food reliably gets eaten inside a week, a zip bag with the air pressed out does most of this for nothing. If you have no freezer space, a sealer makes neater packages of a problem you cannot solve. If sous vide is the only reason you are shopping, you do not need a sealer at all — the water-displacement method closes a plain zip bag perfectly well, which we say in the sous vide roundup too. And if the plan is to put sealed food in a cupboard, re-read the section above, because that is the one thing this appliance must never be used for.
Where it genuinely pays: bulk meat and fish, which is where the maker's own storage tables claim months instead of weeks in the freezer; batch cooking, where portions that freeze flat stack and thaw fast, which is the same logic behind the best appliances for meal prep; garden gluts, with the blanching step the manual insists on; and anything you buy on offer and want to still be good in six months. If two or more of those describe your kitchen, the Anova at the top of this page is the machine we would put on the counter — and if one of them involves soup, the chamber machine is the one that will not let you down.
