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Xiaomi Mi Air Purifier 2S Review: Is It Worth Buying?

Xiaomi Mi Air Purifier 2S Review: Is It Worth Buying?

I decided that I need an air purifier for various reasons. The main one is that I spend over 12 hours in the same room (as my bedroom is also my office – not a perfect setup, I know, but that is it!) Ideal or not, the truth is that I spend so much time in a single room and I need to make sure that everything around me is as perfect as it can get – including the quality of the air that I breathe.

I am fortunate enough to live in Europe, in an area where the air quality is not as bad as it is in other parts of the world, but it’s getting worse each day.

I do suffer from all sorts of allergies, too, and hearing that the Xiaomi Mi Air Purifier (2S or later) cleans the air from allergens as well as other harmful microscopic particles – and it doesn’t cost an arm and a leg like most of the other highly reviewed air purifiers do – I decided to give it a try.

Spoiler alert: I ended up purchasing the Xiaomi Mi Air Purifier 2S later on, so I was really happy. Read on for the entire story.

I did a lot of research before making the purchase and I concluded that the Mi Air Purifier is the safest bet here: since I wasn’t entirely confident that it will make a difference, I considered its low price a risk worth taking. Cheaper products had bad reviews and other air purifiers that had similar or better reviews were a lot more expensive.

So I placed my order on Gearbest, which is a site that usually ships directly from China (where the air purifier is made), but might have options to send from the EU, US or other parts of the world – you just have to check out and see.

However, it doesn’t really matter where you get your Xiaomi Mi Air Purifier shipped from, as it is the same product. And then, a couple of weeks later, the little fellow arrived! (this is the original Air Purifier, but the 2S that I ordered afterwards looks even better, with a sleek new display on it)

Now, it’s worth mentioning that there are a few models available out there: I initially bought the original Mi Air Purifier, but there are more recent versions as well, like the Xiaomi Mi Air Purifier 2s, the 3… but all in all, apart from some minor design differences, these products are basically the same thing.

They have similar designs and all work following the same principles and even use the same filters… so I’d say that this review would apply for any model. But it’s worth having in mind that I am talking about the one I have linked to above.

How does the Mi Air Purifier work?

Now that we’re over the huge intro, let’s get straight to the important part: how does the Xiaomi Mi Air Purifier work and, most importantly: should you get one?

The way this air purifier works is really simple: it is built like a tube with a filter inside, and an internal fan that twists and turns the air in your room.

There are small holes to the side of the Xiaomi Mi Air Purifier that allow it to suck in all the dust and other particles (microscopic or not), which are then kept in the device’s air filter. It filters the air from all sorts of particles – including allergens, pollen and the dangerous for our health PM 2.5 and PM 10 particles.

So it basically sucks bad air in and pushes clean air out!

From starters, the thing that I liked the most about this air purifier is that it can connect to your smartphone via an app and you can control it with your phone – as well as get interesting information about the air quality, how much of the filter is left, how long it’s been running for, the room temperature and humidity and so on.

Here’s how things look in my case, at the moment, in terms of usage:

So, after using it for over 1750 hours (which is almost 3 months, since it didn’t run non stop), I can say that… it definitely works and I am extremely happy with it.

I actually have been using it for more than one year and decided it was so good that I invested in another one for our living room.

I’ve heard many people saying that they completely felt a difference, that they started breathing better and so on and so forth… but that wasn’t really my case at first, to be honest.

Sure, the app itself tells me that the air quality is sometimes low-ish at around 40 PM2.5 which is towards the higher limits of the “good” air quality and with the Xiaomi Mi Air Purifier turned on, the numbers go down to 5 PM2.5, which is great… but the truth is that it’s not really a difference you can feel as these particles generally have no smell.

All I can say is that I have tested it and started shaking a messy rag around it – it was old and full of dust and the air quality indicator on the purifier instantly jumped to over 100, recovering eventually as the device did its job.

So it definitely works and it does clean the air. Probably you get to really feel the difference if you’re in an area with more polluted air: I guess that going down from a constant 200 or 100 to a 9 is easier felt than going down from 40.

Since buying it, I also had moments (especially during the winter here) when the air quality outside was really bad – 150+ and as soon as I opened the windows, the quality of the air inside started to get low as well. So the sensor is working and the air purifier is doing its job!

My air quality early in the morning after opening the window and making the bed
The air quality in my room with the air purifier working, after just 30 minutes.

My main reason for getting the purifier – or at least initially – was the pollen and allergen cleanse of the air. When the allergy season starts, things are horrible for me and having this purifier around makes my life so much easier.

You do have to keep it running constantly in order to have your air clean – and as soon as you open a window, you start sneezing, but all in all it’s much better with it than it was before I got my Mi Air Purifier 2S.

All in all, it’s really nice to have this around and – as you will see further down in this review – there’s actual physical evidence that the purifier cleans a lot of bad stuff from your air. But even without seeing the evidence, you will start feeling better after a few days of using it, your nostrils will be cleaner in the morning (if you have it in your bedroom) and overall you will be satisfied without a doubt.

The annoying part

There is one pretty annoying thing about the Mi Air Purifier 2S: it has multiple fan speeds that you can activate or deactivate as you see fit. The highest fan speed seems to be the most effective, as it really stirs and shakes the air and the dust and other particles in the room.

The problem is that the device automatically slows down after 3 hours, meaning that if you want it to run at full speed constantly, you have to either press the button on it or use the app to turn it back on.

Now, the engineers who built this probably know better than I do and 3 hours might be enough to clean the air in the room for a longer period of time.

But the truth is that on the low fan speed, the Mi Air Purifier doesn’t seem to be able to stir things up to much. It might keep the air around it extremely clean, but not the entire room – or at least this is how I feel is the case.

On the other hand, it does have a lot of time to cycle the entire area in 3 hours and clean the air thoroughly, so if you don’t open the window or allow air pollutants back in, you should still enjoy fresh, clean air.

The problem of the high speed fan is also that it’s not the most pleasant thing to have around during the winter, but I do think it makes everything more pleasant during the summer as it also cools you down a little bit.

But even if you have to constantly increase the fan speed every 3 hours, it’s not a deal breaker in my books.

The design

Compared to all the other air purifiers that I saw – cheaper or more expensive, the Mi Air Purifier is the winner, in my opinion, in the design category.

Apart from its minimalist, elegant look, I also thing that its rectangular shape makes it perfect for keeping the air cleaner, as it basically has a 360-degree working area, sucking in the microscopic particles on all sides.

Official photo of the Mi Air Purifier 2S with its nice display to keep an eye on the air quality.

It is also made in such a way that it remains relatively silent, even when the fan is running at top speed, while running it at lower speeds is practically completely silent.

I haven’t tried sleeping with the high speed fan on as it’s still winter here, but I don’t think I would have a problem with that. However, it would turn off after 3 hours anyway, going silent as the auto mode can barely be heard. So if you’re worried about noise – don’t be! It’s not a problem, even with the fan at maximum speed!


Xiaomi claims that their air purifier needs about 10 minutes to completely clean the air in a regular sized room, so the 3 hours it works on high fan mode should be more than enough for it to deliver and keep your air as clean as possible.

Now, looking at the numbers and indicators on the smartphone app, it does a pretty solid job when it comes to cleaning the air. It even recorded an increase in harmful particles when I did the dirty rag test and cleaned the air up in a breeze (no pun intended!) So it definitely works as advertised.

And when it comes to changing its filter, you will really see that it saved you from breathing in a ton of dust and unhealthy particles. Here’s how my filter looked like when I changed it for the first time:

I was shocked to see it so dirty
You can see here how thick that whole mess was
Finally, replaced with a brand new & clean filter.

From a personal point of view, I can’t say that I really feel a major difference. However, since the air around me wasn’t insanely polluted anyway, it’s understandable. The air pollution is something that harms our bodies long term and generally you won’t feel too much of a difference when the air becomes cleaner.

But it should definitely help your health long term and I am confident that the Xiaomi Mi Air Purifier 2S does that. The allergies test proves it and all the other tests that I ran confirm that it works – including the way that filter looks. It just makes me sick thinking that I used to breathe in all that dirt over the years!

Have in mind that although the product itself is really cheap compared to others, its replacement filters don’t follow the same rule and are relatively expensive (at least when comparing them with the price of the purifier).

You can run a vacuum over them and use them again after the first life cycle, but apparently that reduces how effective they are and you shouldn’t do this more than once.

You can order new filters on GearBest or Amazon. (Affiliate link) However, all air filters are expensive when it comes to air purifiers, so there’s not much you can do here… but it’s an investment worth making and you will most likely only change the filter once each year – and look at my images above if you need extra convincing!

The filter than you need replacing every several months.

All in all, I believe that investing in an air purifier for at least the room where you and your family spend most of your time is a smart decision. The quality of the air worldwide is going down and we should do our best to protect ourselves wherever we are.

These products are becoming, unfortunately, a necessity and not a luxury item in our world today and we owe it to ourselves (and our families) to do our best to keep us healthy. This does mean that we should do everything we can to keep the planet clean and healthy… but also use technology to help when we can’t.

Being fairly priced (despite the relatively expensive air filters), the Xiaomi Mi Air Purifier 2S is a product that I will definitely keep running in my bedroom/office as well as living room, knowing that the air that I breathe is safer thanks to it.

If you agree, you can check out the price and order yours here.


Monday 20th of April 2020

Thanks for the review. To keep the original filter clean, I purchased some electrostatic cotton filters to wrap around the Xiaomi filter. When I install one, it's as white as snow. After a few weeks operation, they become grey or black. Then I put a new one and my original filter is still as blue as on its first day! The cotton filters will block big particles of dust and the Xiaomi filter is blocking pm2.5. After one year, the air purifier asked be to change the filter and was kind of acting strangely. I removed the RFID chip below the original filter and all is fine again now. When the air pollution peaks at 2 or 300pm2.5 outside (I live in a very polluted city) I manage to get between 15 and 40pm2.5 inside my room. Best purchase ever!


Wednesday 22nd of April 2020

Can you please share the details for the electrostatic cotton filters?

Calin Ciabai

Wednesday 22nd of April 2020

Thank you for sharing this tip, I will try it out as well! Happy to hear that you are satisfied with the product, it is indeed doing wonders!

Jackie Solomon

Saturday 28th of September 2019

I just bought version 3!


Thursday 26th of September 2019

I have two of this model in my condo. I highly recommend having them because they do work very well. Through experience I can tell you that you do not need to have it on high speed for 3 hours. I live in Bangkok Thailand and the air is not that great here so I use the filter to clean the air in my condo. To me it appears that when the purifier is showing 10 (and on its way down) that it is similar to a AQI (air quality index) of around 30+ outdoors. Because of this I like to see no more than a 3 showing in the little window of the purifier. I think Mi purposely shows a lower number on the 2s so that the customer does not worry about a reasonable level of PM 2.5. Believe me, these things are great. Mi also makes a portable, handheld, very small PM 2.5 rechargeable meter that you can take with you. This small portable device has been a great help for me to determine where the high levels of 2.5 happen. The maximum reading on this device is 600 and after that it cannot read any higher. Near my condo is a canal which has boats that work as buses to take people up and down the canal and these boats have diesel engines. If the wind is blowing from the back of the boat when it stops and pushes the diesel fumes through the boat it can read 600 and I believe it would go higher if it could. Possibly as high as 1,000. Because of this small handheld device I have been able to determine Hotspots for Air Pollution. As an example when I go to the boat I will not wear a air mask until I get to the pier. When the first boat comes I will put a mask on, and if I am going to my local shopping mall I will wear my mask until I enter the mall away from the doors and then remove it. When I compare the handheld meter to the air purifier they are almost identical. Usually around 1 number different . If the air pollution is bad it does seem to bleed into my condo and hallway exiting my condo. I can open my door step into the hallway close my door and this device will go from a two or a three instantly up to 25 or 30 when the air pollution is bad outdoors. If you want to filter more of your air Mi/Xiomi also makes a Pro Version. The pro version uses the same filters as the smaller 2s system but it has two sets of fans connected together and the box is much larger so it can flow a higher volume of air, cleaning the room more often at a quiet noise level. The 2s is capable of cleaning larger rooms but if you run it at a high speed it is fairly noisy. I have found that I can run mind on manual speed so it can hardly be heard (or not at all) and my air quality remains around 1 or 2. I highly recommend always running the purifier in manual mode so that the speed of the fan can be up versus the automatic mode where the speed of the fan is often too low to properly clean the air. I recommend Outdoors using a cloth material mask 2.5 that can be washed. I actually have about 10 of these masks and can wash them about every two weeks. The need for washing is because the mask will smell inside if it's not cleaned. I use vinegar and baking soda. If you cough inside the mask it will smell and especially if you happen to sneeze inside the mask you will not like wearing it the rest of the day. I do recommend getting the portable Mi Hand Held PM2.5 Meter and determine where the air pollution is high during your daily routine. These air purifiers have made my life much better.

Calin Ciabai

Friday 27th of September 2019

Thank you for taking your time to share your experience! I also purchased a second air purifier from Xiaomi after writing this review, for my living room. It is indeed a perfect product (and I will update the article soon to show, for examples, how the filters look before changing them).

I didn't know about the handheld air quality meter - it does sound like a good addition for somebody who lives in an area that is a bit more polluted than it should be. Great advice overall, thanks for taking the time to share it with us!


Friday 14th of June 2019

Allergy season hit, has it helped?

Calin Ciabai

Monday 17th of June 2019

It isn't very easy to say since I don't spend all my time inside the room, but I have the feeling that my allergies went better this year. I feel the best in the morning - in the past, I used to wake up with a clogged nose and sneeze like crazy until my drops kicked in. This allergy season, while not completely symptom free, I felt better and it was easier breathing. So I would say that although the air purifier helps, it won't completely get you rid of all the symptoms (unless you somehow manage the unadvisable of spending 24/7 inside the room with it running)