Alen FLEX Vs Levoit Core 600S – Trusted Comparison (2023)

The Alen FLEX and Levoit Core 600S are top-in-class air purifiers that can help remove pollutants, allergens, and other harmful particles from the air in your home. However, the Levoit focuses on providing more advanced features along with high-quality filtration capabilities. The Alen, on the other hand, has a sleek design, premium build quality, and outstanding filtration technology.

Alen FLEX Vs Levoit Core 600S - Side by Side
Comparing the sleek designs of the Alen FLEX and Levoit Core 600S air purifiers.

They both use three-stage filtration technology that guarantees fantastic performance and fewer pollutants in the air. 

As for the features and options available, I must say that Levoit Core 600S offers much more. It has an air quality sensor, air quality indicator, auto mode, smart app, and many more features. Alen FLEX cannot boast similar features.

Keep reading the article and find out whether the Levoit Core 600S smart features could be the trigger in deciding which one is a better buying option!

Specs: Levoit Core 600S Vs Alen FLEX

Product ImageLevoit Core 600SAlen FLEX
ModelCore 600SBreatheSmart FLEX
Dimensions (inches / cm)12.3 x 12.3 x 23.6 inches (31.3 x 31.3 x 60 cm)8.5 x 15 x 25 inches (21,6 x 38,1 x 63,5 cm)
Weight (pounds / kg)13.7 lb (6.2 kg)15 lb (6.8 kg)
Clean Air Delivery Rate (CADR)410 CFM (697 m³/h)245 CFM
Coverage (4.8 ACH) 635 sq. ft. (59 m²)300 sq. ft. (28 m²)
Performance Ratings
Filtration TechnologyPre-filter, True HEPA Filter, and Activated Carbon FilterPre-filter, True HEPA Filter, and Activated Carbon Filter
Filter Replacement IndicatorYesYes
Filter Lifeup to 12 months9-12 months
Power Consumption 49W50W
Operating Costs Ratings
Number of Fan Speeds5 – Sleep Mode, Low Mode, Medium Mode, High Mode, and Turbo Mode4 – Speed 1, Speed 2, Speed 3, and Turbo Mode
Air Quality Sensor YesNo
Air Quality IndicatorYesNo
Auto Mode YesNo
Smart App YesNo
Voice Control YesNo
Other FeaturesLight SensorDisplay InfoDisplay LockTimerControl Panel LockTimer
Noise Level (low – high)43.9 – 68.5 dBA41.2 – 53.7 dBA
Noise Ratings
Best Suited For
Living Rooms
Large Spaces
Smart Home Integration
Living Rooms
Neutralizing VOCs
Quiet Operation
Warranty2-year1-year to Lifetime
In-Depth ReviewLevoit Core 600SAlen BreatheSmart FLEX
PriceCheck Price on AmazonCheck Price on Amazon

Features Overview

Straight at first, the obvious difference between Alen FLEX and Levoit Core 600S reflects in the number of features available. The said difference works in favor of the Core 600S, which has more to offer. Let me show you. Keep reading. 

Air quality sensor and Air Quality Indicator

Since Alen FLEX doesn’t have the air quality sensor or the air quality indicator installed, I have to point out the awesome AirSight Plus laser particle sensor Core 600S has. If you have read some of my previous comparisons, you are probably familiar with this feature. Its main job is to track the real-time air quality and send the information to other parts of the device.

For example, the sensor collects data on the current amount of PM2.5 particles in the air and communicates with the indicator placed on top of the air purifier. The indicator will light up in various colors, showing real-time pollution.

The great thing is these two features are running even when the device is in standby mode, and you can always monitor through the app. 

Auto Mode

Another feature available only within Levoit Core 600S is Auto Mode. There is a sort of joint action between the Auto mode and the Air quality sensor. Once you turn this mode ON, the air purifier will be set to the optimal operating level. This means that, depending on the data collected by the sensor, the air purifier will adjust its operating speed. That way you will never have to worry if you are protected enough. 

Top view of the Alen FLEX and Levoit Core 600S
I took a close-up image of upper parts of these air purifiers.

Since this feature is also available through the VeSync app, you get a little bit more from it. By more, I mean three specific operating modes such as the Quiet, the ECO, and the Efficient Auto Mode. I am sure you want more info on these options so go ahead and find it in the Core 600S standalone review, but do come back later. 

Filter Reset Indicator

Before you start thinking that there is no single feature in common, I am here to prove you wrong. Both FLEX and Core 600S have this option. The filter reset indicator turned out to be one of the essentials since it gives one of the most important information that affects the overall air purifier operating system. 

As you may know, that information keeps you updated on how far are you from replacing the air purifier’s filter. Whether you like to keep track by yourself or not, this feature will be nothing but of help. 

Sleep Mode

Having a Sleep mode feature, a little less a stand-alone one puts the air purifier in a competing position. In this case, only Levoit Core 600S has this speed level. Too bad for the Alen FLEX air purifier. You can turn it ON through the app too, and it instantly switches the air purifier to your bedroom’s best friend. It also turns OFF all the indicators within a few seconds. 


Having a Timer is always a plus for any air purifier and it comes almost as a pure must. Keeping your air purifier under control can save you time and money. Since Alen FLEX doesn’t have the Smart App available, you can only set the Timer manually. You get to choose between 2, 4 or 8 hours

As for the Levoit Core 600S, you can set the Timer either manually through the Control Panel or the VeSync app. The first option lets you set the time between 1-12 hours, but the latter one gives you additional 12 hours, meaning the time range is 1-24h

Display off and Display Lock

To show that Alan FLEX is not just a simplified air purifier, the producer gave it some extra features. 

For example, if you wish to use the FLEX in a bedroom during the night, you can easily turn off the indicators by pressing the power button once. Assuming the air purifier is turned ON previously. The next button press will turn OFF the device.

Display or Control Panel Lock serves to protect your air purifier mainly from curious children and pets, as well. A simple 5 seconds button press is enough to activate this option but also to deactivate it. 

Levoit Core 600S also has these two features, only named differently, but the purpose is the same. Only thing is, once you turn ON the Display off feature, the indicators will only be dimmed. 

Smart App

Being able to connect to a Smart app is still a privilege for most air purifiers, even though we’re living in an AI era. However, for the purpose of this comparison, it is important to signify why Levoit Core 600S had the advantage. The VeSync smart app gives so much more options if you wish to entirely use all that this air purifier has to offer. Most features are either unavailable directly on the Control Panel or can’t be entirely controlled. 

And, if you wish to use some of the available online assistants such as Alexa or Google Assistant, you can do it through the VeSync app. Don’t be afraid to use it, you will surely like it as much as I did. 

Control Panel

Positioned at the top of both appliances, Control Panel consists of the most relevant control buttons for each air purifier. I must note that Alen FLEX does have far fewer buttons than Levoit Core 600S. Besides the Power button, there are the filter replacement button, the timer, the speed level, and the lock button. I will be writing about each one of them in this comparison. 

Alen FLEX and Levoit Core 600S control panels
A close-up of the user-friendly control panels on the Alen FLEX and Levoit Core 600S.

The Core 600S has a kind of futuristic control panel, yet somehow I find it difficult to handle due to light reflections that can be quite annoying. In addition to all the buttons that FLEX has, the Core 600S has the Auto and the Sleep mode, air quality, and Wi-Fi indicator, plus the PM2.5 display.

Need I say that all these buttons are also available through the VeSync app? Yes, they are. 


Another obvious fact is the difference in shapes between Alen FLEX and Levoit Core 600S. The first is flat and rectangular, while the other one is cylindrical. Hence the difference in the airflow. The FLEX air purifier has suction holes placed upfront, on both sides, and at the bottom. The air runs through the filters and gets dispersed into the room through the upperside holes. 

On the other hand, Core 600S has air inlets all over the bottom part of the appliance, after which the air gets filtered and released through the grills on top.  


Sometimes, it is not the years of warranty that count, but the quality of the product itself and the producer’s reliability. Levoit company has a verified and proven quality, which is why I believe they might prolong the warranty life from the initial two years

On the other side, wish you become an Alen FLEX owner, you will be protected only for a year. However, if you subscribe to an annual filter replacement from this producer, you will be provided with a lifetime warranty. Hint, more data is available on the website

Coway AP-1512HH Vs Alen FLEX Alen FLEX Vs Levoit Core 400S Related comparisons

Filtration Technology

I am glad to notice that both FLEX and Core 600S share the best possible and optimal combination of filters. Hollow on the inside, Core 600S has a large filter situated at the bottom of the device. And, since this air purifier is CARB certified, it is 100% safe to use

Levoit Core 600S and Alen FLEX Filtration Technology
The Alen FLEX and Levoit Core 600S filters.

The Alen FLEX air purifier has filters positioned frontally. Since filters are not physically attached one to another, you can easily change various available types of filters. There is a basic Dust, Mold, and Pet odors version available. But you can also upgrade it to additional Smoke or Heavy Smoke versions

If you wish for ultimate protection from excessive pollution, this is the combo you need. Let’s see why.


First comes the first, a pre-filter. It is the number one filter that will stop all the larger allergens like dust, lint, fiber, pet hair, and pet dander from penetrating deep into the air purifier. That way a pre-filter also protects the True HEPA filter and allows it to shine. 

True HEPA filter

Being the crucial link in the filtration process it is essential to keep this filter protected from all the large particles that could harm it long term. It is capable of capturing 99.97% of airborne particles, such as dust, smoke particles, and allergens such as pollen and pet hair. 

Activated carbon filter

Coming up as a third in a row, an activated carbon filter is responsible for keeping all the unpleasant and everyday smells coming from your kitchen or pets. For this comparison, I used the second version of the Alen FLEX filter mentioned above, which contains 0.66 lbs of activated carbon and does a great job of neutralizing odors

Contrary, Levoit Core 600S has an exclusive ARC formula, that results in outstanding purifying results. The producer claims that this formula is effective with formaldehyde, benzene, ammonia, hydrogen sulfide, and volatile organic compounds (VOCs).

How to replace filters on both of these devices?

Before I get any deeper into the explanation, remember that both Alen FLEX and Levoit Core 600S have a Filter reset indicator, which will be an important assistant in maintaining your air purifier. 

If you pay close attention to the photos I posted here, you will notice the order of filters within Alex FLEX and the fact that it’s no big deal to replace any of the filters. It will take you from 9-12 months before this process is needed, but if you regularly clean and maintain it, the filter can last for a full year. 

Levoit Core 600S has quite a larger filter than some other air purifiers, so the producer usually recommends replacing it within 6-12 months in order not to affect the performance. Of course, keep it clean and do some vacuuming from time to time and your air purifier will be good to go. 

How to replace Alen FLEX filters? How to replace Levoit Core 600S filter? Filter replacement

Performance Tests 

As I’ve mentioned earlier, Alen FLEX and Levoit Core 600S are almost equally powerful. The first one has 50W of motor power, while the second one has 49W. But the part where they differ a lot is the room coverage. The FLEX air purifier can cover up to 300 sq. ft. while Core 600S can purify twice as bigger space, up to 635 sq. ft. 

In this comparison, I had both air purifiers tested individualy, while running at top speed for an hour. Let’s see the results.

560 sq. ft. Room Tests

Given the coverage that the Levoit air purifier can provide, I expected that this test would be a piece of cake for Core 600S. And it was. An outstanding 96% of improved air quality. But, what surprised me the most is the 94% rate that Alen FLEX reached in the same room size. As you can see for yourself, these two air purifiers can easily dignify competitors. 

Air Quality Improvement In 560 sq. ft. Room
Levoit Core 600S
0% 100%

560 sq. ft. Room

* Data measuring time is 60 minutes.

730 sq. ft. Room Tests

The second test I conducted was maybe too big a bite to chew for Alen FLEX because it improved the air quality by around 89%. On the contrary, the Core 600S reached 93% without trouble, which is a great result. 

Air Quality Improvement In 730 sq. ft. Room
Levoit Core 600S
0% 100%

730 sq. ft. Room

* Data measuring time is 60 minutes.

Overall, the Levoit Core 600S is slightly better at performing what it is supposed to do, which is to provide you with clean air. 

Noise Test

To begin with, Alen FLEX has three basic speed levels with the additional Turbo mode. Even though it is missing the Sleep Mode, this air purifier is SleepScore certified. This means that the noise it produces, or so-called Pink noise, helps the user to sleep better, without interfering the sleeping process. With a noise between 41.2-53.7 dBA, this is one of the most silent air purifiers I have ever tested. 

The Levoit Core 600S has a different situation. It comes with low, medium, and high fan speeds, along with the Sleep and the Turbo mode as stand-alone speed levels.

While in Sleep mode, this air purifier produces 43.9 dBA, which is above the FLEX noise level, but still good enough to be able to keep it in the bedroom during sleep. As the speed increases, the noise level does get higher, especially while in Turbo mode when it reaches up to 68.5 dBA. However, the Turbo mode always brings better airflow, so I can’t quite complain about it. 

Product Noise Range (dBA)
Alen FLEX 41.2 – 53.7 dBA
Levoit Core 600S 43.9 – 68.5 dBA

No matter that the Levoit Core 600S is an excellent device, in this case, I was utterly overwhelmed by the impeccable and sleek Alen FLEX purifying process. Being so silent, you will barely notice it is in the same room as you

Operation Costs

When two tech products have almost the same motor power, it is not always easy for a user to make the right decision. In that case, some other factors get involved. Such as the product price, which is not going in favor of Alen FLEX this time. Especially since replacing the old filter with the new one would also cost less in the case of Levoit Core 600S. That is why I like putting devices to a test, to see if they’re really over/underestimated. 

Image of the Levoit Core 600S and Alen FLEX motors
The powerful motors that drive the Alen FLEX and Levoit Core 600S air purifiers for efficient air cleaning.

I have left both air purifiers running for a whole month, 24h at the top speed level. By the end of the testing period, the Alen FLEX air purifier gave me a $2.1 electricity bill. As opposed to it, Core 600S got me $4.2 to pay. 

Product Wattage Range (W)
Alen FLEX 0.4 – 24.3W
Levoit Core 600S 1.2 – 48.2W

For me, Levoit Core 600S feels like a better and more affordable version. It is not only about the initial product price but also looking at it in long term, you wouldn’t have to spend much money on replacing the filter. 

Which One Does It Better?

The Levoit Core 600S and Alen FLEX are designed to improve your room’s air quality. Outstanding results in performance tests, reliability, and long-lasting filters characterize them both. And, whichever you choose, I’m sure you won’t be wrong.

However, the winner’s title in this comparison goes to the Levoit Core 600S air purifier. It is an excellent device with smart features and outstanding filtration technology. It performed slightly better than the Alen FLEX, is suitable for much larger rooms, and is cheaper for annual maintenance.

Do you have any questions or suggestions after reading the comparison? If you have, please add a comment in the comment box below the article.

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