Keurig K-Duo Vs Ninja DualBrew: Which Is The Better Coffee Maker?

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If you can't decide between a pod-style and a drip coffee maker, the Keurig K-Duo and the Ninja DualBrew are both great options that combine both machines into one. It's nice to have a machine with a large-capacity drip coffee maker for better flavor control, as well as a single-serve coffee pod option for convenience. However, without doing a deep dive into every feature and review, it can be challenging to determine which machine is the better choice. Luckily for you, we did have the time to look at both dual coffee makers from every angle to figure out which is best.

There are many similarities between these two machines. They're both easy to use and allow you to either quickly pop in a pod for a single cup or make multiple cups with coffee grounds. However, we started to notice differences immediately, such as how they deliver coffee, which brew styles they offer, how their unique technologies affect flavor and temperature, and how reliable they are. And only one offers cold brew capabilities. How well each machine fared across these and other categories helped inform our decision about which dual brewer is likely to make you happiest. If you're ready to make a decision between the Keurig K-Duo and the Ninja DualBrew, you're going to want to keep reading to see how these machines compare and which you're likely to enjoy most.

Prices are as of the date of publication and may vary based on region.

When looking at the Keurig K-Duo and the Ninja DualBrew side by side, you'll notice some immediate differences and similarities. They both have digital readouts and physical buttons. However, everything else is fairly different. So, let's get those differences in their external presentation out of the way first.

Their presentation is very different. The Keurig has one side for pods and another for the carafe, while the Ninja makes all sizes and styles of coffee in a single central area. The Keurig's 72-ounce water reservoir is hidden in a detachable compartment behind it, while the Ninja's is conspicuously located on the side and holds only 60 ounces.

Secondly, there's a difference in color and size. Both come in black with silver trim. However, the silver trim on the Keurig is matte rather than shiny. Plus, it has a "moonlight gray" color option instead of black. The Keurig is shorter (12.7 inches versus 15.45 inches) and weighs about the same (9.6 pounds versus 9.3 pounds). Its shorter profile may help it fit better under lower-hanging cabinetry. However, the Ninja takes up less countertop space since it isn't as deep or wide (10.09 x 10.668 inches versus 11.1 x 12.9 inches). While the Keurig provides information about the machine's height when open, the Ninja doesn't, leading to complaints about it being too tall.

Both machines have dual-brew capabilities and can brew large quantities of coffee, but there are some drastic differences in how that works for each. For both, dual brewing means that you can use either pods or ground coffee beans. Also, for both, you can opt to brew into a single-serving cup or into a carafe. So, the options are single or multiple servings, pods or grounds, or 6 ounces or 12 cups at a time.

First, let's look at what brewing looks like for each one of these. The Keurig K-Duo is like two separate side-by-side machines in one: one side for brewing a carafe of coffee with coffee grounds, and the other for making single-serve cups with K-Cups. Meanwhile, the Ninja DualBrew has a more integrated feel since you place your cup or carafe in the same spot, where the machine can dispense coffee either from a pod (it also uses K-Cups) or from coffee grounds.

Both machines offer four K-Cup brewing sizes of 6, 8, 10, and 12 ounces. They also both let you brew a carafe of coffee using grounds, with four size options each. However, the Ninja has one big advantage. While the Keurig can only brew single servings using K-Cups, the Ninja can also brew individual cups using grounds. The Ninja actually offers 10 different brewing sizes for ground coffee, ranging from a small cup to a full 12-cup carafe. So, if you prefer using ground coffee rather than pods, the Ninja gives you more flexibility there.

First, we want to look at what the two different machines are capable of doing when it comes to brewing a single cup at a time instead of brewing into a carafe. While there are plenty of tricks to make a better cup of coffee, sometimes the options on your machine matter as well. Both machines have four different brew styles related to coffee strength or temperature, but one machine's options might speak to you more than the other's. We'll discuss how well these buttons actually work for strength and temperature later.

Besides its regular brew mode, the Keurig K-Duo has three other options for making single cups with K-Cups. You can either brew over ice, do a strong brew, or brew it extra hot. The brew over ice setting automatically adjusts the brewing temperature, starting hotter to extract flavor before cooling down to minimize ice melt. However, the Keurig doesn't have a dedicated cold brew mode for this machine.

The Ninja DualBrew also has three brew modes besides its classic one: rich, over ice, and rapid cold brew. If you make cold brew coffee often, this setting might be the one that wins you over, especially since it eliminates the need to research buying a separate cold brew coffee maker.

There's a huge difference between the Keurig K-Duo and the Ninja DualBrew in terms of the options you have for brewing coffee in the carafe. The Ninja is the clear winner here, since it offers far more options for carafe brewing than the Keurig.

Keurig's star feature has always been its pod brewing, which is why it's not terribly surprising that the carafe seems more like an afterthought. While the K-Cup side of the K-Duo offers many temperature and strength options, the carafe side for coffee grounds doesn't have a way to adjust temperature or strength.

In stark contrast, the Ninja offers the same options for its larger-capacity carafe coffee as it does for its single-serve K-Cup coffee. This makes sense since you brew both in the same area of the machine. Thus, you have your classic brew as well as an option for rich coffee, coffee over ice, and rapid cold brew. The main difference is that K-Cups are limited to single servings, while ground coffee can be used to brew an entire carafe. Brewing times also vary depending on the amount of coffee you're making. For example, Ninja says its rapid cold brew feature can make a single cup in under 10 minutes or a full carafe in under 20 minutes.

Both machines have unique technology and features that the other doesn't have. However, the tech and extras on the Ninja seem to improve customers' experience with the machine overall.

Unsurprisingly, the Keurig K-Duo focuses its technology on the K-Cup pod side, using Multi-Stream Technology to better saturate the coffee. Those who have used Keurigs before say this feature improves the flavor. There is some tech on the carafe side as well, but it's fairly basic, like a stay-warm plate that keeps coffee warm for four hours or programmed brewing that lets you set your coffee to brew up to 24 hours in advance. Unfortunately, reviewers say that you have to reset the autobrew function daily, which can be annoying.

The special technology for the Ninja DualBrew is its Thermal Flavor Extraction, which applies to all coffee sizes and both pods and grounds. This technology helps with coffee extraction and strength, ensuring that the flavor is never bitter and that iced coffee isn't watered down. Ninja fans say this tech improves the flavor over basic machines. There are a few bonus features included. The foldable cup tray makes it easier and cleaner to fill shorter cups. The Ninja Smart Scoop has a storage nook on the machine and has measurement markings to make it easy to know how much coffee to add. It also comes with a paper filter kit, but you can replace the paper filters with a permanent one.

Both the Keurig K-Duo and the Ninja DualBrew are easy to use and have decent brewing speeds. They feature uncomplicated controls that are intuitive and straightforward. However, which machine is faster seems to depend on what size you're making.

With both machines being super easy to use, you're likely to be able to make a cup or pot of coffee straight out of the box without needing to pore over the instructions. For either one, you simply choose from pod or carafe, select the number of ounces or cups, and apply any special brew settings before brewing. Both have easy-to-set auto brew functions.

The Keurig seems to do pod brewing faster, while the Ninja seems to do carafe brewing faster. If you're wanting just a single 12-ounce cup of coffee from the Keurig, it's ready just around 45 seconds to a minute after pressing the start button. Meanwhile, the Ninja seems like it might do single-serve coffee a little slower, with customers saying it takes just under two minutes. However, a full pot from the carafe takes a little longer with the Keurig, with reviewers citing between two and 10 minutes versus sometimes as little as three to five minutes for the Ninja. Reviewers also like that they can get cold brew coffee in minutes with the Ninja, rather than waiting hours with traditional cold brew methods, whereas the Keurig doesn't offer this feature.

There are pros and cons for each machine when it comes to strength and temperature. The Keurig seems to do a better job with coffee strength, while the Ninja seems to do better with the temperature of its freshly brewed coffee.

If you like a strong cup of coffee, the Keurig may be the better choice. The Keurig's "strong" button helps make the single-serve pod coffee nice and bold. In fact, a few reviewers say the Multi-Stream technology in this model makes stronger coffee than older Keurig models. However, without any extra strength settings on the carafe side, it just doesn't always come out strong enough when using grounds to make larger quantities. There are also complaints about not being able to get the coffee strong enough from the Ninja, even with the strong brew (rich) setting, because the machine brews too quickly and at temperatures too low to develop much flavor. This seems to apply to pods or grounds rather than just to the carafe.

There are a few temperature complaints for both machines. There are a few gripes about coffee from the Keurig only coming out lukewarm or only staying hot for about 10 minutes, even when using the "extra hot" button with K-Cups. Several Ninja fans have measured the temperature of the coffee as it poured from the machine and found it plenty hot. However, the Ninja's warmer plate may not keep the carafe as warm as some owners would like.

Overall, the Keurig K-Duo and Ninja DualBrew are easy to clean and maintain. However, there are some cleaning challenges for both carafes.

Overall, Keurig owners don't complain much about cleaning it. Reviewers like that it doesn't drip a lot onto the drip tray. However, it can be a bit of a challenge to clean the carafe, since it's not dishwasher-safe and the lid only opens partway without coming off. The good news is that the carafe's spout design prevents drips when pouring. The water tank pulls away from the machine, which makes cleaning a lot easier than with some other models where the tank is attached. Some people have bought extra filters to keep the water even cleaner. Some owners of this machine who have owned previous Keurigs or Duos have learned that cleaning and descaling often increase the machine's lifespan.

As for the Ninja, you can remove the filter holder for easy cleaning. The carafe is removable, too. You can also access the pod needles to wipe them down or clean out clogs. Overall, the carafe for this machine is easy to clean, but some people have warned about a sharp plastic piece inside. Some people who have had previous Ninja machines miss some of the cleaning features that those older models had.

While the warranties for the Keurig K-Duo and the Ninja DualBrew are similar, the reliability and durability of the machines are pretty different. At the time of writing, nearly 25% of Amazon reviews for the Keurig fall below 4 stars, with 20% of those being in the 1- to 2-star range. In contrast, only a little over 15% of the reviews for the Ninja fall below 4 stars, with just over 10% being in the 1- to 2-star range. Both have a one-year warranty. However, overall, the Keurig seems less reliable from the get-go when looking at the lowest Amazon reviews. 

We found a large number of complaints about the Keurig failing within days or weeks of purchase. Brew amounts can be erratic, error messages abound, the machines sometimes won't start, and sometimes they even trip a breaker. Reviewers with problems don't always seem to have great experiences with customer service or the warranty process. One person had four machines fail (including three replacement machines). Because of the higher chance of the Keurig breaking down after a year, some buyers decide to get Asurion insurance just in case, whereas no reviewers for the Ninja mention buying insurance.

There are far fewer people complaining about the Ninja. Problems include unclearable error messages, clogging, the coffee not coming out hot, inconsistent volume, inconsistent strength, and simply stopping working altogether. Those who have contacted the company about their problems seem to have better resolution results than with Keurig. 

Most reviewers feel that both the Keurig K-Duo and the Ninja DualBrew are a good value for the price. However, the Keurig sometimes goes on sale, making it significantly cheaper than the other.

While the regular price for the Keurig is higher than that of the Ninja, that's not the whole story. At the time of writing, both the Keurig website and Amazon list the regular price of the K-Duo as $219.99, while both the Ninja website and Amazon list a steady price of $179.99 for the DualBrew. The Keurig's price sometimes drops to $129.99, making it up to $50 cheaper than the Ninja. So, be sure to watch the sale price if you're making your decision based on price alone.

Keurig reviewers regularly say that they feel that the K-Duo is a good value for the money, as do reviewers for the Ninja DualBrew. They mention the fact that they're getting both a K-Cup pod brewer and a coffee maker with a carafe, all for the same price. Interestingly, there are more reviewers who feel that the Ninja may be overpriced, even though it also offers cold brew capabilities that the other doesn't. In our minds, you're getting three machines in one with the Ninja, which makes it seem to us like a better deal overall (along with its other attributes).

There are some similarities between these two machines, like both having the ability to use K-Cups or regular coffee grounds, being easy to use, having our different brew style choices, coming with a one-year warranty, and being a good value for the price. However, when you look at the differences, our verdict is that the Ninja DualBrew is the better choice because it has more pros than the Keurig K-Duo. Don't get us wrong; there's still plenty to love about the Keurig K-Duo, but the Ninja DualBrew seems to come out ahead far more often.

Despite Keurig's positives, there are far more advantages to the Ninja DualBrew. First of all, it takes up less countertop space since the carafe and K-Cup brew from the same location. It's capable of brewing 10 different sizes instead of just eight. Keurig does make great K-Cup coffee, but it's not the only good single-cup coffee maker on the block. All the technology that improves flavor and strength for the Ninja applies to both single servings and whole pots of coffee. Plus, it's the only one that can make cold brew coffee. The paper filter kit, scoop, and foldable tray cups are all nice bonuses that the Keurig doesn't have. It seems to produce coffee with a better fresh-brewed temperature, and there are fewer low ratings based on the machine failing. Plus, its regular price is lower.

To determine whether the Keurig K-Duo or the Ninja DualBrew was the better coffee maker, we looked at all the machine specs on the company websites and Amazon, as well as user reviews. We evaluated each machine for various attributes, including external attributes, what was possible with each brew style, special technology, features, ease of use, speed, flavor, temperature, and cleaning and maintaining. 

Plus, we looked at the reliability, durability, warranties available, price, and value for the money. In the end, the winner, the Ninja DualBrew, was the one that had a longer list of positive attributes in comparison to the Keurig K-Duo.