Levoit 400S Air Purifier – The Best?

Released just a few weeks ago on April 18, 2021, Levoit is now selling their brand new 400S model air purifier. I’ve been testing the 400S in several different rooms in my house over the past two weeks and I’ll share my results here.


I’ve been shipped a complimentary unit to review from Levoit. While we were given the unit to test and review, the opinions expressed below are my own and in no way influenced my overall review of the product.

We’ve been eyeing an air purifier for our new home in the desert area of South West Texas for a couple of years but never got around to actually getting one. The shopping journey was quite daunting with all the choices out there and not knowing who’s product review you can really trust.

It’s really dusty here and the HVAC air filters downstairs and upstairs constantly have to be changed every 4-6 months. Our allergies are especially bad during the windy season, which seems to be year round! So I knew we really needed an air purifier in my home. 

As we’re all concerned about our baby and our family’s health, especially from the air we breathe, I thought an air purifier would be a great addition.

Levoit 400S Promo Code

For our readers, get 5% off the Levoit Core 400S air purifier!
Valid 5/10/21 – 5/17/21
Promo Code: 5CORE400SKOL (apply at Checkout)

Why Levoit?

Levoit is America’s #1 selling air purifier company. Before we were even contacted by them to review their soon to be released air purifier 400S, I had already decided Levoit was going to be the brand I bought for my home. I just couldn’t decide which one, and in our Texas sized home, I didn’t see any of their air purifiers, in stock, that could support a 400 Square Foot room. So I delayed my purchase and moved on to other projects like landscaping for the Spring.

The Best Air Purifier

The right air purifier for your home depends on several factors:

  • Room: Identify the room you want purified
  • Filter Size: Measure how many square feet the room has
  • Quiet Operation: Determine if the air purifier in the room will have to be quiet (ie needs to be quiet as it’ll be in a bedroom)
  • Filtration Level: Select how much filtration you want the air purifier to handle

Previous Core series air purifiers have favorable reviews on CNET and Oprahmag.com, and from my experience, I fully expect the 400S to also get rave reviews. 

The main concern is buying one properly sized for the room you want it in. You could have a terrific air filter but if it’s in a room that’s too large for it’s filtering capabilities, you’ll probably end up disappointed. I tend to shop for ones that are larger than needed, just to be on the safe side.

Levoit 400S Air Purifier Specs

Here are the specs of the Levoit 400S:

  • Max Room Size: 400 square feet
  • Room Air Exchanges: 5 in an hour
  • CADR Rating: 260 CFM
  • Filter Lifespan: 
  • Noise Levels: 24 dB to 52 dB

Levoit Core 400S

The 400S is part of the “Core” series of air purifiers. It’s the largest model in this series that filters up to a 400 square foot room which will filter the air 5 times in an hour. The “S” on the end of 400S also signifies it is 1 of 2 Core Series air purifiers that is Smart connected. 

Levoit Smart Connected Air Purifiers

The previous high-end air purifiers I purchased were all very basic devices. They had an on/off switch and fan speed. That’s it. It was all about the filter!

Fast forward to today, we have WiFi connected air purifiers. Upon opening the 400S I thought having a smart connected air purifier was gimmicky and useless at best. I quickly changed my tune after seeing how easy it was to connect to it from an app, get WiFi on my protected network setup and configured, and all of the functionality I have using the app.

VeSync App

The app was free, easily downloaded, and went into a setup wizard. It automagically found the air purifier, connected to it, got it connected to WiFi, and ended with me having full remote control of the air purifier! Super impressed.

Everything you can do from the air purifier, you can do on the app. At least I’ve found that to be true so far. 

Probably the most useful thing I found from the app was the dirty air history. The app records every 15 mins the dirtiness of the air around the air purifier. 

What I Love About The 400S

There are way more controls than I know what to do with on the 400S. Things like setting up schedules to turn on and off the filter. Programming the fan speed on pre-set intervals, etc. 

The killer function to me is the “Auto” setting. With one click of a button, I just leave the air purifier running 24hrs a day and depending on the dirtiness of the air, it automatically increases or decreases fan speed. This has worked the best for me. 

Levoit 3-Stage Filtration System

Like other Core series air purifiers, the 400S uses their state of the art 3-stage filtration systems. This new 400S uses their Levoit ARC Formula, which is a fancy name to mean it’s a top of the line air purifier. It easily purifies dust (I have plenty of that here), pollen (we even have that here with all the home owners landscaping in the desert), pet dander (yes, I have that too with our family Pug), and smoke particles (none of that). 

It ships with a H13 True Hepa Filtration system. 

The 3 Stages

Stage 1:  Pre – Filter, gets the larger particle such as hair, lint, pet fur, and bigger dust particles.

Stage 2: HEPA Filter, removes 99.97% of all air pollutants down to 0.3 microns in diameter. This is especially effective in removing cooking odors, fireplace smoke, or cigarette smoke.

Stage 3: Carbon Filter, absorbs gasses such as smoke, VOC’s (volatile organic compounds) commonly used in cleaning products.

Noise Levels

Levoit air purifiers are among the quiet ones. None of their units cross the 55 dB noise levels.

In fact, the 400S runs 99% of the time in any of our bedrooms at the lowest speed, which I’m assuming means its only 24 dB’s loud. 

To put that in perspective, 20 dB’s is equivalent to whispering. That’s barely audible. I and my daughter don’t even notice it running at night while we’re sleeping.

Setup Process: Simple enough for anyone to do

As you can see in the unboxing video below, setup is super simple. 

Setting up the Levoit 400S air purifier couldn’t be any easier. The purifier comes completely assembled. All you need to do is rotate the unit upside-down, twist off the bottom panel, and remove the round HEPA filter out of the unit so you can remove the plastic bag it ships in. Then re-insert it, replace the bottom panel, and lock it back on, and you’re ready to use it.

Plug it in, and you’re done. You can run the unit completely from the touch panel on the top of the air purifier. If you’re interested in the app (I highly recommend it!), download the app from the Apple AppStore or Google Play, launch it, and it’ll start a wizard and practically get connected for you.  The whole process took us less than 5 minutes which included downloading and setting up the App.

Design: A modern and clean look

I live in a Desert Modern house. Stucco on the outside, very clean lines, and very modern looking. The 400S is white with blue indicator lights and blends in beautifully. 

It’s a great looking air purifier that I think would fit in any home. 

Night Mode

One of the things I’ve disliked on many air purifiers I’ve owned in the past is the brightness of the display screen. So many of them were so bright during sleep, it bothered my sleep. I’d have to resort to getting an index card and tape and using that to cover the display screen.

On the first night, I experienced that problem. I thought this was such a “smart” air purifier, perhaps they had resolved this issue with a dimmer switch. After reading the manual, indeed, they did have a solution for the screen brightness during sleep. It’s called “Night Mode”. All you have to do is activate it on the display screen, or using the VeSync app!

At first I thought I’d be able to use the VeSync to setup a schedule that automatically enables the Night Mode, but it does’t appear that I’m able to do that with the way I run the 400S 24hrs a day. The solution though, is to enable Night Mode all the time. If I need to use the display screen, just tap the screen and it’ll turn on. I actually find myself using the VeSync app 100% of the time and never using the display screen, so I just leave Night Mode enabled 24 hours a day.

Levoit 400S Unboxing

The Levoit was shipped to my house and it came in a carboard box. And inside of that was the product box. It came well packed and had zero damage to the unit or the boxes.

Here’s an unboxing video:


We first had the 400S in the master bedroom. It’s common for me to wake up around 2 – 3 am with a stuffy nose. I figured my allergies were kicking up due to something in the air (mold spores?). After running the air filter for about a week, then looking back at the history of the air quality, not once did it ever cross higher than 003 ug/m3 as measured by their laser dust sensor with PM2.5 measurement standard. I determined air quality in the master bedroom was way better than I had expected. 

At first, I thought the laser sensor must not be that sensitive and not all that accurate. As a test, I removed the bed sheets and fitted new ones. The next day I checked the history, and it spiked to 18 ug/m3, as you can see in the chart below. Very cool to see that the sensor actually picked up all that dust, the Auto Setting sped up the fan, and filtered it all out in about 3 hours back down to 002 ug/m3.

To continue testing, I moved the 400S to my daughters room. Unlike the master bedroom, it’s carpeted, has a kid living in it, and has her little Pug in there most of the day and all night. 

Frequently Asked Questions

Final Thoughts

Levoit Core 400S air purifier is an excellent and large air purifier that is easy to use and has great room coverage. I’m so glad they made a large unit that can finally work for my house. It is ozone free and safe for kids and pets too.

Even though I was given this unit to test, my unbiased opinion is that I probably would have bought this unit anyways. I was waiting for a 400 square foot air purifier. Little did I know the Core series didn’t have one yet! 

I wholeheartedly recommend the 400S. It can filter large rooms, but the size of the unit itself is like a small trash can. It looks beautiful and looks and works well in any room in our house. 

1 thought on “Levoit 400S Air Purifier – The Best?”

  1. Thank you for all the information. I was wondering Which system I would use to cover the whole first floor. 1000 ft.². Open concept.

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