Keurig K-Express vs K-Slim

This is our comparison of the Keurig K-Express vs K-Slim coffee makers.

The Keurig K-Express and K-Slim are two of Keurig’s smallest, most basic coffee makers. But what makes these machines special, and how do they differ from each other?

Not all coffee is created equally. Here at The Coffee Arsenal, we scour the internet and, through meticulous research and experience, provide you with the most comprehensive coffee guides to ensure your coffee is as good as it can possibly be.

After our research, we’ve found that the K-Express is better than the K-Slim for most everyone.

Keep reading to find out why.  

Overview: Keurig K-Slim vs K-Express

keurig k-express

Keurig K-Express

keurig k-slim

Keurig K-Slim

The Keurig K-Express comes with a 42oz water reservoir, 3 brew sizes (8, 10, and 12 ounces), strong mode, and some additional features like Auto-Off.

On the other hand, the K-Slim, comes with a 46oz water reservoir, 3 brew sizes (the same as the K-Express), MultiStream Technology, and some additional features pretty identical to the K-Express.

Also, you have more colors to choose from and the control panel is more user-friendly than the one in the K-Express.

As you can see, the major differences between them are the water tank (for 4 ounces) and the brewing technology.

We have decided that the K-Express is better mostly because of its value for money compared to the K-Slim.

The K-Slim is about 40% more expensive and being honest, you can have a really nice experience by using the K-Express, and you won’t miss the K-Slim’s features.

If you want to know more, keep reading our Keurig K-Slim vs K-Express review.

Here’s an introductory video of the Keurig K-Slim.

Here’s an introductory video of the Keurig K-Express.

Comparison Table

SpecificationsKeurig K-ExpressKeurig K-Slim
Brew Sizes8oz, 10oz, 12oz8oz, 10oz, 12oz
Water Tank Capacity42oz46oz
Removable Water Reservoir✔️✔️
Charcoal Filter Compatibility✔️✔️
Product Dimensions12.6” (17.2” when open) H x 5.1” W x 12.8” D12.1” (16.7” when open) H x 4.7” W x 15.2” D
ColorsBlackBlack, White, Scarlet Red
Strength Controls1 setting1 setting
MultiStream Technology✔️
Descale Light✔️✔️
Add Water Light✔️✔️
High Altitude Settings✔️✔️
Hot Water On Demand✔️✔️
Quick Brew✔️✔️

Reviewing the Keurig K-Express vs K-Slim

Here, we deep dive into the details that differentiate the Keurig K-Express vs Keurig K-Slim to help you decide which is a better fit for you. 

Brew Sizes

The Keurig K-Express brews coffee in three sizes: 8 ounces, 10 ounces, and 12 ounces. The K-Express also supports back-to-back brewing, which means you don’t have to wait for the machine to reheat between brew cycles.

The Keurig K-Slim also brews coffee in three sizes: 8 ounces, 10 ounces, and 12 ounces. Additionally, the K-Slim comes with Smart Start, where the water heats up and brews all at once. (Same )

Both machines can accommodate travel mugs up to 7 inches tall.  

As both machines brew coffee in the same sizes, they are tied in this area.

Winner: Tie

Water Reservoir

The Keurig K-Express has a single position water reservoir that holds 42 ounces of fresh water. The reservoir is compatible with Keurig’s charcoal water filter. 

The K-Slim also has a single position water reservoir, but is slightly larger, able to hold 46 ounces of water. Additionally, the K-Slim’s water reservoir is also compatible with Keurig’s charcoal water filters. 

The two machines are almost identical when it comes to their water reservoirs. Both are single position and removable.

The main difference between them is that the K-Slim’s water reservoir is 4oz larger than the K-Express’s. However, if you think about it, you can’t do much with an extra 4oz of water.

Winner: Tie

Ease of Use

Both of these machines are extremely easy to use. The Keurig K-Express button layout is on the side of the machine, and has buttons for each of the brew sizes, in addition to a button to control strength.

The Keurig K-Slim has its control panel on the top, it has just three buttons to control the brew size.

Both machines have indicator lights to remind you to add water and to descale. This is very useful since you don’t have to remember when to descale the machine.

If you want to learn more about how to use these coffee makers, you can check their official user manuals below.

Winner: Tie

Brew Quality and Performance

Both the Keurig K-Express and K-Slim brew good coffee and perform well as convenient, easy-to-use brewers. 

One of the first things to note when comparing the K-Express and K-Slim is brewing time. The Keurig K-Express was far and away the faster machine, taking a little under 50% less time to heat and brew an 8-ounce cup of coffee. 

From brew button press to brew completion, the K-Express took a minute and eight seconds at the 8-ounce size. The K-Slim took one minute and thirty-eight seconds

Both the K-Express and K-Slim are relatively silent machines. You won’t have any trouble with excessive noise like some of Keurig’s earlier machines. 

During testing, we found that both coffee machines produce coffee with temperatures ranging from 160F to 170F. (These are temperatures after being served).

These are standard temperatures, not too hot, but not too cold. For most people these temperatures are ok.

The Keurig K-Express comes with a strong brew setting, which, as you might assume, allows users to brew a stronger cup of coffee. This works by slowing down the water as it passes through the K-Cup, allowing the water to collect more flavor and strength.

The Keurig K-Slim does not have a strength setting, however, the MultiStream technology allows you to brew the same quality coffee as the K-Express with the strong mode enabled.

Overall, both machines brew good coffee, and are convenient and easy to use. If we have to decide a winner, we would choose the K-Express since it brews coffee faster than the K-Slim.

Winner: Keurig K-Express

Capsule Compatibility

Neither one of these machines has Keurig’s pod scan technology. As such, both the Keurig K-Express and K-Slim are compatible with any K-Cup pods in addition to any equivalent third-party pods.

Both of these machines also work with the My K-Cup Universal Reusable Coffee Filter.

Winner: Tie

Cleaning and Maintenance

Cleaning and maintenance on both of these machines is very similar, and following these recommendations can help your machine work at peak performance for longer.

Regularly wiping down the machine, and rinsing the water reservoir and drip tray can help keep the machine looking its best.

Descaling is also necessary, you’ll get an alert reminding you to descale. This helps minimize mineral buildup and protects the internal components of the machine. 

The descaling process is easy and follows Keurig’s standard descaling procedure. 

The manual on the Keurig K-Express has some instructions that you can follow to keep your machine working perfectly.

Keurig K-Express regular maintenance instructions

Keep in mind that you should not dry the inside of the water reservoir with a cloth, as thread and other microscopic debris can infiltrate the internals of the machine.

The K-Slim doesn’t have this table, however, it has very detailed instructions too.

Keurig K-Slim maintenance instructions

Winner: Tie

Design, Dimensions, and Weight

The Keurig K-Express and K-Slim are very similar in terms of design and dimensions.

Both machines are really small and can fit into even the smallest kitchens and office spaces.

Both have pretty basic designs and plastic builds, but we thought the silver accented handle on the K-Slim looked a little more premium and added some flair. 

On both machines, the drip tray can be removed and coffee can be brewed directly into travel mugs up to seven inches tall. 

Here are the dimensions of the K-Express:

  • Height: 12.6” (17.2” when open)
  • Width: 5.1”
  • Depth: 12.8”
  • Weight: 4.1lbs

Here are the dimensions of the K-Slim:

  • Height: 12.1” (16.7” when open)
  • Width: 4.7”
  • Depth: 15.2”
  • Weight: 6.22lbs

Both machines are pretty small and can fit in most places.

The K-Express comes in one color option, black, while the K-Slim comes in three color options, black, white, and scarlet red.

We think that the K-Slim looks a little bit more premium, and the extra color options help it fit better in different kitchen and office space designs.

As we said before, the K-Slim comes with the control panel at the top, while the K-Express has the control panel at the front.

After doing some testing, we found that having the control panel at the front is a little bit uncomfortable since it is very close to the brewing system and mug.

So, just because of the variety of colors and the control panel on the top we consider the K-Slim to be the best choice in terms of design.

Winner: Keurig K-Slim

Additional Features

While both are relatively basic machines, there are some additional features worth mentioning when comparing the Keurig K-Express vs K-Slim. 

Travel Mug Friendly

Both the Keurig K-Express and K-Slim are compatible with travel mugs up to seven inches tall with the removal of their drip tray. 

This is extremely nice, as it allows you to brew directly into the travel mug instead of brewing into a cup and pouring it in. 

MultiStream Technology

MultiStream technology is a new brewing method from Keurig that involves five needles puncturing the coffee capsule instead of just one. 

This results in a more even extraction, and helps preserve the coffee’s flavor integrity while taking full advantage of all the ground coffee inside the capsule. 

The Keurig K-Express does not have MultiStream technology, while the K-Slim does. 

This is a major point in the K-Slim’s favor, as this MultiStream technology helps it brew better coffee. 

High Altitude Settings

Different water temperatures are optimal for brewing coffee at different altitudes.

A high altitude setting will lower the water temperature to prevent damage to the internal components of the machine, as the water boils at a lower temperature at higher altitudes.

The Keurig K-Express has a high-altitude setting, which can be activated by pressing and holding the power button and 10oz button for 3 seconds. The 12oz button will illuminate to confirm that the High Altitude Brewing Mode has been enabled.

The K-Slim also has a high-altitude setting. This can be turned on by holding down the 8 ounce button and the brew button.

Keurig recommends that you turn on high-altitude mode anywhere over 5,000 feet.


The Keurig K-Express has an auto-off feature. This is extremely nice, as it helps save electricity. The machine turns off five minutes after the last brew cycle. 

The Keurig K-Slim also has an auto-off feature, which functions the same way. 

Hot Water On Demand

For both of these machines, you can get hot water on demand by executing a normal brewing cycle, just without a pod in place.

This is a great feature to have, as it allows users to conveniently get hot water for making tea, hot chocolate, ramen, and other hot items.

Which One Has the Best Additional Features?

Overall, both come with the same additional features, but the K-Slim comes integrated with the MultiStream Technology. Since this technology improved the brewing performance, we will consider them as be equal on this aspect.

Winner: Tie

Pros and Cons: Keurig K-Express vs K-Slim

Both of these machines are slim, convenient to use, and brew good coffee. However, there are some pros and cons of each that need to be mentioned when comparing the Keurig K-Express vs K-Slim.

Keurig K-Express

Here are some of the pros and cons of the Keurig K-Express.


  • Back to back brewing
  • Bold setting for extra flavor
  • Inexpensive
  • Fits in any kitchen


  • No MultiStream technology
  • Smaller water reservoir
  • Only one color option
  • Menu can be difficult to access

Keurig K-Slim

Here are some of the pros and cons of the Keurig K-Slim.


  • Larger water reservoir
  • MultiStream technology
  • Slim design
  • Menu is very accessible from the top


  • No strength controls
  • Takes more time to brew than some of its competitors’


You are very close to the end of our Keurig K-Slim vs K-Express review, and by now you should have a very good idea between them. If you’ve reached this point, and you don’t like these machines, here we provide you with a couple of nice alternatives.

Keurig K-Compact

keurig k-compact
  • Key Feature: Space-saving design
  • Brew Sizes: 6oz, 8oz, and 10oz
  • Water Reservoir: 36oz
  • Material: Plastic
  • Brand: Keurig

The Keurig K-Compact is one of Keurig’s slimmest brewers with a removable water reservoir. It’s a fantastic no-frills, low cost option for people who just want to brew coffee and don’t have a ton of space to do it. 

The K-Compact brews coffee in 6 ounce, 8 ounce, and 10 ounce sizes. Travel mugs up to 7 inches are compatible for brewing with the removal of the drip tray. 

This is a good option for people who want to brew coffee in smaller sizes, as the K-Slim and K-Express do not have 6 ounce brewing options.

Here are the dimensions of the K-Compact:

  • Height: 12.5″ (16.3″ when open)
  • Width: 8.2″
  • Depth: 13.2″
  • Weight: 6.9 lbs

As you can see, the K-Compact’s dimensions are comparable to those of the K-Express and K-Supreme, although the K-Compact is a little bit wider. 

The Keurig K-Compact has a smaller 36 ounce water reservoir, which is removable to make refilling easier.

Brewing is extremely quick, faster than both the K-Express and the K-Supreme. An 8 ounce cup of coffee takes about forty-six seconds from brew button press to brew completion.

While brewing is fast, the older pump system results in a much louder brew than the K-Express and K-Supreme. 

Coffee flavor was good, but not as good as the K-Slim or Express. The coffee tasted a little weaker, with less flavor integrity and smoothness. However, it is more than sufficient for the everyday coffee drinker. 

Overall, the Keurig K-Compact is a great, budget machine for people who value speed and simplicity over all else. 

Keurig K-Mini

Keurig K-Mini
  • Key Feature: One cup reservoir
  • Brew Sizes: 6oz to 12oz
  • Water Reservoir: 12oz
  • Material: Plastic
  • Brand: Keurig

The Keurig K-Mini is another one of Keurig’s compact brewers, and is really designed for travel. 

The K-Mini is small – standing at just 4.5 inches wide, the K-Mini is easy to fit in even the smallest kitchen or office space. 

The brewing process is incredibly easy – just insert a pod, add fresh water between 6 and 12 ounces (this will be the size of your cup), and press the brew button.

The K-Mini operates a bit differently than the K-Express and K-Slim. The K-Mini will heat the water completely, and then push it through the K-Cup all at once.

This means that it takes more time for water to start coming out, and is slower than the K-Express and K-Slim.

The K-Mini comes with a non-removable water reservoir. This makes cleaning and refilling a little bit more difficult.

If you like the K-Mini but want a removable water reservoir, check out the K-Mini Plus. (Check the differences between the K-Mini vs K-Mini Plus).

The Keurig K-Mini is made using more environmentally conscious plastic, and has saved over a million pounds of virgin plastic since 2020.

The K-Mini comes in six different color options, which is great if you’re looking to add some character to a space.

The Keurig K-Mini does not have any strength control settings, or temperature control options. 

The K-Mini does have an auto-off feature, which helps conserve energy. Additionally, there is a pod storage box on the bottom of the machine, which helps make brewing even more convenient. 

In all, this machine is perfect for people who are looking for a small, simple machine that brews good coffee and is easy to take with you during travel or on camping trips.

For more information on the differences between the K-Mini and the other machines mentioned in this article, see the resources below.

The Bottom Line: Keurig K-Slim vs K-Express

After reading this review, you should have a pretty good idea about the differences between the Keurig K-Express vs K-Slim. 

However, if you’re still unsure, here’s the bottom line. We think that the Keurig K-Express is the better machine for almost anyone on the market for a brewer. 

It just works, offering more value for the money with its strength controls, faster brewing time, removable reservoir, and cheaper price.

Don’t get us wrong, the K-Slim is still an excellent machine. The MultiStream technology helps brew a smoother cup of coffee, and the slightly larger water reservoir is nice. We just don’t think it’s worth spending twice the money on.

If you like the MultiStream technology and the design of the K-Slim then you should definitely go for it.

Leandro Santorsola
Leandro Santorsola

Leandro is the founder of The Coffee Arsenal. His favorite relaxation method is to drink a Cafe Latte in the afternoons.