Keurig K-Slim, K-Express, & K-Compact Compared Side-By-Side

k-slim vs k-express vs k-compact

The Keurig K-Compact which was released in 2018 is the most basic entry level reservoir-style brewer available and I think it’s a better value buy then the K-Slim which was released in 2020.

Both units fall under the reservoir-style brewer category, unlike the K-Minis which are “water-in-water-out” style brewers, and the Compact still uses an internal heating tank to heat the water up, just like the older style Keurigs did.

k-compact is better than the k-slim
IMO the K-Compact is better than the K-Slim, and I’ll explain why further down this page.

► FYI – As of January 2024 Walmart still has the best price on the K-Compact and they occasionally slash the price throughout the year. See the K-Compact on right here.

In the Spring of 2021 Keurig released a new design, the K-Express & the K-Express Essentials, which is available only at Walmart. It is part of the Keurig Essentials product line because it only features the basics of what is needed to brew K-cup coffee.

The Express is kind of like a mashup of the K-Compact and the K-Slim in that it’s also a small reservoir style brewer having just a few buttons on it to push, but it uses the newer instant heat water line instead of the internal heating chamber.

In my opinion these units are basically an upgrade to the K-Slim (better design) instead of a replacement to the K-Compact…and they all have a similarly small price tag.

FWIW, the K-Express Essentials is my favorite of the two Express models because it offers a 6oz cup instead of a (way too large) 12oz cup option.

k-express is an upgraded k-slim
IMO the K-Express is an upgraded K-Slim (pictured here is the K-Express Essentials)

► FYI – In 2022 Keurig started selling a K-Slim + ICED model which added the brew temperature adjustment feature for iced coffee. It’s a lot more expensive than the K-Express or the regular K-Slim so I still don’t think it’s worth it.

See Amazon’s super low pricing on the K-Express right here.

The Most Important Differences Summarized

All three brewers feature a removable 36-oz water reservoir, a single needle, and three cup sizes to choose from. The K-Slim and K-Express offers a 12-ounce cup size while the K-Compact and K-Express Essentials offer a 6-ounce option. Although the K-Compact can make a cup of coffee in well under one minute the Slim and Express give you longer water to grind contact time resulting in better tasting coffee. The K-Express brews for a full minute (and at a higher brew temperature) making it the best option of the bunch.

Because the Express Essentials is cheaper and offers a 6oz setting it’s easily my favorite of these entry level k-cup machines.

Cup Size Comparison

6oz 8oz 10oz 12oz
 K-Slim   Yes Yes Yes
 K-Compact Yes Yes Yes
K-Express  Yes Yes Yes
 K-Express Essentials Yes Yes Yes

I have a full page on this site where I list my favorite Keurig machines from the premium, value, and entry level categories. None of these machines are on my best list but the K-Express is featured on my best value list. You can see pricing on K-Express Essentials through any of the following retailers: Walmart | Amazon.

Alternatively you can see my thoughts on all of the best Keurigs here, you know, the higher end models.

URGENT UPDATE – Although the K-Slim isn’t my favorite of these three, pricing for it is usually extremely low directly on Keurig’s website right here.

URGENT UPDATE 2 – The best price I’m currently seeing for the K-Compact right now is right here, this is a bit lower than Amazon’s pricing however certain colors can sometimes be found lower at Amazon right now as well.

Lastly, the K-Express Essentials is best purchased at Walmart. It also happens to be the cheapest of all three most of the time (but not always). Here’s a direct link.

Now with that out of the way I want to show you my brief video review of the K-Express. Feel free to skip this part if you want. This link will take you to the style differences of the three machines lower on this page.

The Shortest Review of the K-Express On YouTube

Make sure to see these related comparisons for more context on the other brewers these machines compete with:

K-Slim vs K-Mini (Plus)
K-Mini vs K-Mini Plus
Difference Between K-Compact, K-Classic, and K-Select
K-Express vs K-Mini

The Older Style (K-Compact) vs The Newer Style (K-Slim & K-Express)

Styling of the K-Compact Essentials is similar to both the K-Slim and the K-Supreme so one might look at it as a stripped down K-Supreme…but I see more as a better version of the K-Slim.

As for performance I feel like it does really well just like many other Walmart Essentials brews like the K-Latté and K-Duo Essentials, both of which I find to be great values compared to their premium counterparts.

I particularly like how the K-Express uses the fixed place k-cup holder, allows for the use of the Universal My K-Cup, has a side mounted water reservoir and takes up minimal depth and width on a countertop. It doesn’t feel too wide or too deep like some of the other machines they make.

For instance the K-Compact has nice proportions but the water reservoir is cumbersome to remove, refill, and replace while the K-Slim is very deep (albeit skinny) making it stick out really far on a countertop while also making it hard to refill with the reservoir placed in the back.

Before we talk much more about the Express Essentials, I wanted to show you a full video comparison I made of the K-Slim to the K-Compact. You can see that comparison in the video embedded below.

In that video it’s clear that I don’t like the K-Slim very much so I don’t recommend it to many people but there are a select few that it would be perfect for.

In 2021 however with the introduction of the new K-Express on Walmart shelves the entry level Keurig market got a bit more muddy. Let me explain a bit about the slight differences between the K-Slim and the K-Express and why I feel like the New Express model is better even though it’s so similar.

Why The K-Express Is Better Than The K-Slim

This section doesn’t need to be long because the things that matter the most in this comparison are simple to explain.

The K-Express has a water reservoir that is slightly smaller by about 10-oz (even though both boxes say they are the same size) but refilling the Express Essentials is much easier. It is side mounted and it includes a nice little carrying finger hold.

You can physically put approximately 49-oz of water into the K-Slim compared to 39-oz into the K-Express…and both offer the ability to add a charcoal water filter if you choose to buy one.

► Make sure to see my recommended Keurig accessories on this page.

Because of the shape (design), the Slim is very deep and it sticks way out on the counter; too far if you ask me. The Express however is more rectangular and doesn’t feel like it takes up much more side-to-side space and it doesn’t come close to sticking out as far…and because of the side mounted water reservoir you don’t ever have to move it around on the counter except to clean under it periodically.

Both brew coffee a bit too fast for my liking with the Express taking about 4 seconds longer, so that’s mostly a non-issue but because the K-Slim won’t even give you the option of brewing a 6-oz cup of coffee and because it brews at a lower temperature the quality of the coffee you get from the K-Express will usually taste a bit better…so long as you stay away from the gigantic cup sizes, 10 & 12.

The best tasting coffee almost always comes from the smaller cup sizes and especially when strong settings are used which neither of these machines offer.

For budget sensitive shoppers looking for low cost k-cup coffee makers I recommend at least considering non-Keurig models that offer a strong button in this same price range. You can see my recommendations for those types of machines here.

Now let’s talk a bit more about how these three machines actually brews coffee.

Does The K-Express, K-Slim, or K-Compact Brew Better Tasting Coffee?

Overall I think the K-Express makes the best tasting coffee of the three. It’s brews at about the same speed as the K-Slim but offers a better 6-oz cup size options and brews a bit hotter than the K-Compact.

Both the K-Compact and the K-Express give you the ability to brew a 6-oz cup of coffee too meaning these are the only two machines that can brew a full bodied cup without the use of a reusable k-cup that can hold enough grind to support 8-10oz cup sizes.

All three units can accept water filters too (if you choose to buy one separately) so that can help with coffee flavor especially in households that have poor tasting tap water.

Related Reading – Do Keurig Machines Make Good Coffee At All?

How Fast Can You Get A Cup Of Coffee?

None of these machines give you adequate grind-to-water contact time to make a full bodied cup of coffee but overall it’s fine for most people looking for a budget, entry-level machine.

In fact most people shopping for a cheap Keurig probably care more about speed of brew than I do so to answer your questions I’ll give you a list of actual speed tests I’ve done on all of these machine.

How Fast Does The K-Compact Brew Coffee?

From an “off” state with a room temperature internal heating tank the water heats up to brewing temperature when you turn the machine on in 105 seconds.

Once the internal tank has come to temperature and you press the 8-oz brew button it takes 12 seconds before the first drip and then an additional 33 seconds of brew time.

For subsequent cups brewed from an already heated internal water tank it takes only 44 seconds from when you hit brew until your 8-ounce cup of coffee is ready.

The internal heating tank will turn itself off automatically two hours after the last brew unless you turn it off manually or unplug the machine.

This machine also brews pretty hot compared to other Keurig machines. Coffee in cup measures 181 degrees, higher than all of these devices so even though it brews a little fast for my liking it at least brews hotter so flavors are able to extract correctly.

How Fast Does The K-Slim Brew Coffee?

Unlike the K-Compact the K-Slim pumps water on demand through a heating tube instead of into a heating tank. When you hit the brew button on the 8-ounce setting it takes around 9-12 seconds for the water to start dripping out of the brew basket into your cup.

Because there are no bold settings or strength selectors the 8-oz brew time is the same every time.

It takes about 55 seconds for my K-Slim to go from first drip to shutoff giving you plenty more water-to-grind contact time over the K-Compact. Unfortunately the machine won’t let you brew 6-oz cups sizes and the brew temp is lower too.

In my K-Slim I consistently measure coffee in the cup at 173 degrees which is considerably lower than the K-Compact’s 181.

Because the brew temp is lower and I can’t brew smaller size cups of coffee I would recommend the K-Compact over this unit most of the time.

Related: How Keurig Strength Buttons Work

How Fast Does The K-Express Brew Coffee?

Because the K-Express doesn’t have an internal heating tank (just like the K-Slim) when you turn the machine on it is ready to go. Water will start flowing through the heating tubes right when you turn the machine on and hit the brew button.

When you press the 8-ounce brew button it takes about 9 seconds for the first drip to get to your cup.

After the first drip it takes an additional 60 seconds to brew a full 8-oz cup and then the machine turns itself off right away because there is no internal tank to keep warm.

I measure coffee in the cup at about 181 degrees on average when I use a pre-heated coffee mug, but the last ounce or so comes out closer to around 170. Even still this machine will consistently brew coffee at a higher temperature than most other K-cup brewers.

A Few Questions I Get All The Time
How To Unclog A Keurig
Do Travel Mugs Fit Under Keurig Coffee Makers?
What Are The Smallest K-Cup Coffee Makers?

Still Not Sure Which Keurig To Buy?

These entry level models aren’t the only Keruigs worth looking at, many of the higher end models can usually be purchased with big discounts throughout the year so I recommend looking at a few other higher end models to see if pricing is good enough to upgrade units.

Linked below are some other Keruig model reviews and comparisons I have published here on the site for your convenience.

K-Cup Coffee Maker Reviews
Keurig vs Cuisinart
Best Biodegradable & Compostable K-Cup
K-Mini vs K-Compact
Difference Between The K-Supreme Plus & K-Supreme Plus SMART
K-Elite vs K-Select
K-Elite vs K-Supreme
Keurig K-Café vs Nespresso Vertuo Plus
Keurig K-Supreme Plus SMART Review

Brian Mounts

Head blogger, editor, and owner of "Top Off My Coffee", a website that has been educating readers about coffee brewing techniques and equipment since 2012.

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