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Keurig K Slim vs Classic: Which One Should You Buy?

Keurig K Slim vs Classic

Keurig makes a variety of coffee makers to choose from. Many are specifically designed to be used in homes that don’t have a lot of counter space, such as the Keurig K-Slim.

Another example of a fairly compact model is the Keurig K-Classic. Both are decent coffee machines, though, which might leave you wondering which one is better for you.

We’ll be comparing the Keurig K Slim vs Classic in this guide. We’ll tell you about their similarities and differences, as well as give you advice on how to choose between them.

Quick Summary

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Keurig K-Slim

Keurig K-Classic


Keurig K- Slim Single Serve K-Cup Pod Coffee Maker, Multistream Technology, Black

Keurig K-Classic Coffee Maker K-Cup Pod, Single Serve, Programmable, 6 to 10 oz. Brew Sizes, Black

Water Tank Capacity

46 ounces

48 ounces

Drink Sizes

8, 10 & 12 ounces

6, 8 & 10 ounces

Pods Compatibility



Grounds Compatibility






Available Colors


Black and Rhubarb

Ideal Uses




Keurig K- Slim Single Serve K-Cup Pod Coffee Maker, Multistream Technology, Black

If you’re short on room in your kitchen, finding a modestly sized coffee maker can seem impossible. In situations where every single inch of space matters, there are machines like the Keurig K-Slim. This Keurig is less than five inches wide, making it one of the skinniest models on the market and therefore perfect for those who want convenience in a compact package.

Keurig K-Classic Coffee Maker K-Cup Pod, Single Serve, Programmable, 6 to 10 oz. Brew Sizes, Black

The Keurig K-Classic is very well-named because it is a classic example of Keurig’s famous user-friendliness. There are several light indicators on the top that tell you whenever your Keurig needs water, descaling, or is heating up, making this model ideal for anyone who’s new to the world of Keurigs and wants a straightforward coffee maker.


Pods or Grounds

One aspect that makes Keurig coffee machines so well-known is their flexibility. Most of them, including the K-Slim and Classic, can use K-cup pods or grounds.

If you’re unfamiliar with what a pod is, it’s a pre-measured amount of coffee grounds in a small capsule. They come in a huge range of flavors, so you can just choose one you like and put it in the Keurig. After choosing the size of drink you want, the Keurig will brew the pod for you.

Many coffee afficionados will insist that coffee grounds are better, though, especially if you grind the beans yourself shortly before brewing. This allows you to get a more concentrated and fresher flavor than what you would usually get from pods.

These coffee machines give you the best of both worlds. Out of the box, they’re compatible with pods. You can use grounds in them, too, but you will need to purchase the My K-Cup Universal Coffee Filter that allows you to do so separately first.

Water Tank Capacity

To be honest, these Keurigs do not have an identical water tank capacity – there is a slight difference. Not surprisingly, the Classic’s water tank is a little bit larger and can hold up to 48 ounces.

The K-Slim, on the other hand, can hold up to 46 ounces. However, we chose to include this under similarities because that 2-ounce difference isn’t likely to impact your use all that much on either one.

Overall, they have a very similar water tank size. Either machine will allow you to brew multiple cups of coffee before you need to refill them, which could be important if you’re sharing the machine with friends and family.

Indicator Lights

These days, everyone has multiple appliances in their kitchen. Unless you’re a very technical person, perfectly maintaining all your appliances can be a challenge.

If something breaks down, figuring out what happened is difficult. The Keurig K-Slim and Classic simplify this process by telling you with lights when they need maintenance.

Both will tell you when they need to be descaled or when they need more water. Lights will flash on at the tops of either coffee machine whenever this kind of maintenance is necessary, so you’ll never forget when you need to take care of them.

Removable Drip Trays

Both the K-Slim and Classic include removable drip trays that double as shelves for your cups. Their placement allows them to catch any extra drips that might come from the dispenser once you remove your cup, protecting your countertops.

But when you remove the drip trays, you make extra room beneath the dispenser. This allows you to fit taller cups under the machine, such as travel mugs and sometimes even tumblers.

Another benefit to being able to remove your drip tray is that it makes cleaning easy. Instead of having to wash the drip tray out while it’s attached to the coffee maker, you can detach it and clean it in your sink.

Auto-Off Function

Forgetting to turn off an appliance can lead to an unpleasant surprise when you get your electric bill for the month. Unfortunately, it can be all too easy to forget to turn your appliances off when you’re in a hurry.

That’s where the Keurig K-Slim and Classic come in to help you. They both have an auto-off mode, which means they’ll turn off by themselves when they haven’t been in use for a period of time.

Removable Water Tanks

Like with the drip trays on the K-Slim and Classic, the water tanks on both can also be removed. The benefit to this design is obvious.

Imagine if you couldn’t remove the water tanks, and your Keurig needed a refill. You’d have to carry a pitcher of water over and try to carefully pour it in, or you’d need to bring your entire coffee machine to a water source. This is clearly not a very convenient design.

Removing the water tank makes the task of a water refill easy. Furthermore, cleaning the water tank is easier when you can wash it in your sink as opposed to trying to scrub it while it’s attached to your coffee machine.

Simple Controls

Have you ever had an appliance that was filled with complicated buttons and settings? When you get something with more buttons than you need, most of the time, you even end up not using all of them.

That’s what makes the Keurigs a breath of fresh air. They only have as many buttons as you need to brew yourself a cup of coffee, tea, or hot chocolate.

You’ll be able to turn either coffee machine on, then choose a size for your cup. That’s about it – no need to struggle with complicated and obscure settings.


Drink Sizes

Either the Keurig K-Slim or the Classic have multiple drink sizes to choose from, but the sizes they offer are slightly different.

The K-Slim allows you to brew an 8, 10, or 12-ounce cup whenever you want. To give you some perspective, the smallest 8-ounce size is enough to fill your average mug about three quarters of the way up.

On the Classic, you’ll be able to brew 6, 8, or 10-ounce cups. There’s some overlap with the sizes of the K-Slim, with the only difference here being the smallest and largest sizes on each model.

If you’re looking to make larger drinks, you’ll probably prefer the K-Slim, because it allows you to brew a 12-ounce cup.

Keurig K-Classic Color Choices

Your kitchen, like the rest of your home, might follow a specific decorating style or color scheme. In that case, you’re probably looking for appliances that fit in with the other décor.

In this comparison, the K-Classic is slightly more flexible. You can get it in either a neutral black that’s easy to blend in anywhere, or rhubarb, which is a bright red color.

The K-Slim is only available in one dark gray color. It’s still easy to match with other colors, but the K-Classic is just a bit more visually versatile.

Keurig K-Slim Compact Design

The K-Slim has the perfect name because, just like its name, it’s very slender. In fact, it’s under five inches wide.

With such a tiny footprint, the K-Slim can squeeze in between other things on your counter effortlessly. If you’re short on space, it could be the perfect coffee machine for you.

The K-Classic, in comparison, is almost twice as wide. It’s still a modest 9.8 inches wide, but the K-Slim is better for those with little room to spare.

Read Also: Keurig K Slim vs Mini Plus

Keurig K-Classic Heating Light

It’s an extra touch that won’t really change how you use it, but the K-Classic comes with a heating light. When the K-Classic is getting ready for the next brew cycle by heating up another batch of water, a red light will come on at the top.

This signals to you that the coffee machine is working as normal. You’ll know exactly when it’s ready to begin brewing.

Which One Should You Buy?

Both of these coffee makers are excellent models if you’re a beginner at brewing your own coffee. So how do you know which one you should buy?

That comes down to what you need from your coffee machine. Everyone has different circumstances, and ideally, your Keurig should work for your own specific needs.

For instance, the K-Slim will be the choice for you if you’re in need of something that can easily squeeze in between other appliances. When your space is in short supply, this is the perfect coffee maker for you.

But if you need something with more visual variety, the K-Classic is the winner. Because you can get it in two different colors, it can fit into a wider range of settings.

You can consider drink sizes, too. Think you’ll need a larger cup more often? Then you’ll want the K-Slim because of its 12-ounce cup size.

If you want more information on these Keurigs, you can learn more about them by clicking the links below:

Keurig K-Slim

Keurig K-Classic

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