Xiaomi Mi Band 4 Review: Fitness tracking done right and done cheap, again

Xiaomi Mi Band 4 Review: Fitness tracking done right and done cheap, again

One of the biggest draws from Xiaomi as a brand is the fact that one can expect a really strong value deal from practically everything that the company decides to put its name to — ranging from smartphones to accessories to just about everything in the Xiaomi ecosystem. In countries like India, Xiaomi has brought about a revolution in the segments that it has existed in, pushing down prices very hard and driving up the utility to the end-user. Much of the same is true for Xiaomi’s presence in the fitness tracker segment — a segment that was once dominated by expensive options that did the task well but could be afforded by only those who were serious about staying fit. Xiaomi’s entry into the fitness tracking segment with the original Mi Band sowed the seeds of rapid change, expanding the target audience of this segment from established fitness aficionados to amateurs who were just looking to get started. With the new Mi Band 4, Xiaomi is bringing in some big, and colorful, changes to its fitness tracker, making a competitive product even more attractive. The band has been very well received in China, selling out 1 Million units within just eight days of its launch in the region; so we expect to see similar fireworks in other regions.


So, does the Mi Band 4 live up to the hype? Read on as we find out.

Xiaomi Mi Band 4 – Specifications

Specifications Xiaomi Mi Band 4 (Asia) / Xiaomi Mi Smart Band 4 (Europe)
Display 0.95-inch AMOLED, full color, capacitive touch screen
Display Resolution 128 x 240
Color Depth 24 bit
Screen Brightness Adjustable, up to 400 nits
Screen Protection 2.5D Tempered Glass with anti-fingerprint coating
Weight 22.1g
Water Resistance Rating 5 ATM
Buttons Single Touch Button for waking up and going back
Battery 135mAh LiPo, non-removable
  • 3-axis accelerometer
  • 3-axis gyroscope
  • PPG heart rate sensor
  • Capacitive proximity sensor
  • Bluetooth 5.0 BLE
  • NFC (China only)
Wrist Band
  • 18mm width
  • 155mm – 216mm adjustable length
  • Material: Thermoplastic Polyurethane
  • Removable
  • Compatible with Mi Band 3
Pricing ~$30 in certain regions


The Xiaomi Mi Band 4 is immediately recognizable as the successor to the Mi Band 3, but it comes with its own set of differences. With the Mi Band 4, Xiaomi has opted to upgrade from the Mi Band 3’s 0.78″ OLED touchscreen to a 0.95″ AMOLED full-color touchscreen. This is the single biggest difference across the two generations, and the changes it brings along are positive. The display on the band is now bigger, brighter, colored and has greater visibility in broad daylight. The display alone immediately elevates the Mi Band 4’s value above its price point and makes it worth the year-on-year upgrade all by itself. You can now see more data on your wrist with a simple glance, and opting for a color display opens up the possibilities of customizing the watch faces through many more combinations.

Xiaomi Mi Band 4

The display alone immediately elevates the Mi Band 4’s value above its price point and makes it worth the year-on-year upgrade all by itself.

Comparatively speaking between the Mi Band 3 and the Mi Band 4, the casing of the tracker is now thicker. The front glass now has a flat appearance against the curved edge display on the Band 3; and there is no indentation for the touch button, which is a non-issue either way. Xiaomi has managed to retain cross-compatibility for the straps across the two generations of bands. Both the Mi Band 3 and the Mi Band 4 come with a black color strap, and other color options need to be purchased separately. Since the bands are compatible, you can use the bands that you purchased for the Mi Band 3 on the Mi Band 4 with no issues, as I did.

What isn’t cross-compatible is the charger, as the Mi Band 4 comes with a new charger design. The tracker now has pogo pins exposed on the bottom as opposed to the pogo pins being stealthily hidden away on the side in the previous-gen product. Despite the change, you still have to pop out the tracker from the strap to charge it. The charger has a cup-like design, with a USB Type-A on the other end of the wire. Chargers have always been a weak point for the Mi Bands in my experience — I have had difficulty in getting my tracker to charge reliably, consistently and effortlessly on the Mi Band 3; and I foresee even more of the same as the Mi Band 4’s chargers are worse in my opinion. Even within just 3 charges, I have already begun facing issues with getting my tracker to tightly sit within the charger cup — the pogo pins just bounce it out all the time, and the small latches on the inner sides of the charger are ineffective to hold the tracker in place due to the build material and design of the charger. I have had to hold my tracker in place by placing a heavy object on top, so I count the charger as a negative. Hopefully, Xiaomi explores better charger designs for the next generation. Magnets, maybe?

Xiaomi Mi Band 4 Charging

The Mi Band 4 that is sold in China comes with NFC for payments and a microphone to control Xiaomi’s voice assistant. Both of these hardware features are absent from the Band that is sold outside of China. For an Indian user like myself, where NFC is barely used, the absence of NFC is not a big issue. But for users in Europe where NFC sees higher usage for payment solutions, the lack of this hardware module can be a problem. Similarly, the absence of a microphone could be an issue for users who rely on voice assistants a lot — but do note that in China, this microphone is tied to Xiaomi’s voice assistant. You cannot use it with other assistants or for other functions.

Overall, I really like the design on the Mi Band 4. It has a very understated and discreet look to it, one that does not have any intention of drawing attention to itself. This may not work in the favor of the Band when the occasion demands a flashy accessory on your wrist, but my personal preference is for function over form, and the Mi Band 4 aces this aspect.

User Interface and Experience

The user interface with Xiaomi’s fitness tracker is divided into two parts — what you see on the band and what you see on your device through the Mi Fit app.

Mi Band

The Mi Band 4 lets users use customizable watch faces (band faces?). There are a few options available within Mi Fit, but you can also easily sideload watch faces from third-party websites such as amazfitwatchfaces.com, and even use animated faces. Depending on the watch face, the band homescreen can display the time, day, date, steps taken, distance walked, calories burned, and band battery status. You can also set up the band to display your notifications from your phone —  because of the color display and the larger screen size, you can now see app icons and more data at a glance, bringing along a lot of utility when compared to the Mi Band 3.

You can swipe left from the homescreen to quickly jump into the music control screen. With this screen, you can control music which is currently playing on your connected smartphone. You can resume, pause, go to the next track or previous track and control volume. Volume controls are not very fine and change in large steps — but there’s only so much you can do on such a small display. Music Control is one of my favorite features on the new Mi Band 4: my new Sony WF-1000XM3 noise-canceling earbuds do not come with volume controls, so having the ability to control volume came in handy on my wrist.

Xiaomi Mi Band 4 - Music Control

Xiaomi Mi Band 4’s music control features came in handy for me when I had to charge my phone at the airport, and still wanted to listen to music through my wireless earbuds.

Another handy addition is the ability to lock the Mi Band 4 with a 4-character PIN (1 to 4 only) when it is not being worn. This fixes one of the minor issues I had with the previous Mi Band 3, as now others cannot read your notifications (in uncleared history) if you leave the band unattended. When the Band 4 is locked, only the homescreen is visible.

Swiping down on the homescreen brings you pages for Status (Steps, Distance, Calories, Idle Alerts), Heart Rate, Workout (Outdoor Running, Treadmill, Cycling, Walking, Exercise, Pool Swimming), Weather, Notifications, and More (DND, Alarm, Music, Stopwatch, Timer, Find Device, Silent, Band Display, Settings (Brightness, Lock Screen, Reboot, Factory Reset, Regulatory, About)).

There’s a lot to explore within the Smart Band, but unfortunately, I could not locate any means to hide away options that I do not plan to access regularly, as one could on the Mi Band 3. This appears to be an odd omission, as there are far more features that can be initiated or accessed right from the band itself without needing the Mi Fit app. Some means of organization would have been appreciated here, and I hope a future update to the Band firmware brings back this ability.

Mi Fit

The second leg of the Mi Band 4 experience rests with the Mi Fit app, which can be downloaded on both Android and iOS.

The Mi Fit app should be familiar to anyone who has used a Mi Band in the past, as it serves as the primary means of communication with your Band. The Mi Fit app is divided into three tabs: Workout, Friends, and Profile. Most of the changes related to the Mi Band 4 reside within Profile > Mi Smart Band 4. From here, you can control and customize various aspects of your band, including loading up the different watch faces and setting up which apps can notify you on the Band, and idle alerts. The app is also needed to update the firmware on the Band from time to time, so it does form an essential part of the Mi Band 4 experience.

If you would prefer not using the Mi Fit app, you currently do not have a lot of options. The primary recommendation of Gadegtbridge, the open-source app that lets you connect to various trackers without needing to transmit any data to the vendor, has not yet been updated with Mi Band 4 support.


The Mi Band 4 focuses on fitness and activity tracking as one of its highlight selling points, and for the most part, the Mi Band 4 does not disappoint, especially when you keep in mind its price.

The Mi Band 4 comes equipped with a 3-axis accelerometer and a 3-axis gyroscope, allowing users to count their steps, track distance walked and calories burned. The band is particularly sensitive towards registering steps, as I often ended up walking ~30 steps in my sleep, despite not really moving out of bed. This count came through the hand movements I probably made during my sleep. Trying out controlled and counted walking, the Band has a variance of about ~3%, meaning that you are likely to register hand movements and incomplete steps as complete steps too. The inaccuracy is within bearable limits though, and the Mi Band 4 should provide you with reliable data on your steps for the most part. You can also view your step count history to get a better idea of how your performance has changed over time.

The Mi Fit app attempts to categorize activities automatically, which is great if you are a casual user who wants to spend more time doing the activity rather than pouring through data. These data categorizations can sometimes be off, so if you prefer your data to be accurate, I would suggest periodically monitoring the same. Inaccuracies with categorization are an inherent limitation to smart trackers, so I do not judge the Mi Band 4 too harshly on this aspect.

Much like how the step tracking is handled automatically, sleep tracking is also handled automatically. The thicker Mi Band 4 may not be as comfortable as the thinner Mi Band 3, so you would need some getting used to the increased bulge on your wrist while sleeping, especially if you come from the earlier Mi Band. The performance in this section is admirable, as the Mi Band 4 has been accurately able to detect when I fall asleep and when I get up, with variances lower than 2 minutes. I find this impressive because I usually spend a lot of time in bed peeking at my phone before falling asleep and after getting up, often using my phone with the kickstand to watch movies or catch up on YouTube. So wrist movement during these periods slows down without me falling asleep — and the Mi Band 4 handled it all like a champ.

Heart rate measurements on the Mi Band 4 have been a stark improvement. I have had very poor experiences with heart rate measurements on previous Bands from Xiaomi, as they failed to pick up any readings whatsoever because of my darker skin tone. This is an issue with how light-based heart rate sensors work, as they often are unable to pick up blood flow readings through darker skin. I have experimented with having friends with lighter skin tones use the same bands (Mi Band 2 and Mi Band 3 in this context), and the bands promptly returned readings. On my wrists, the same bands failed to pick up data even after multiple attempts right after they had reported success.

With this Band though, the experience has been entirely different. For the first time in my Band experience, I could manage to get complete readings without having the Band derp along the way. I do not have any means to verify whether these readings are accurate, but the fact that I managed to get some is a success in my books.

The Xiaomi Mi Band 4 also provides dedicated tracking for sports, namely Outdoor Running, Treadmill, Cycling, Walking, Exercise, Pool Swimming. While the band does not have a dedicated GPS within itself, the Band 4 can leverage the GPS of your phone to track the routes you take for activities like Running and Cycling. You also get some more detailed information here, such as average heart rate, stride, cadence, and others, depending on the activity.

Battery Life

Keeping up the positive note in this review, we come to the battery life on the Mi Band 4. Just like most things that Xiaomi sticks its name on, the Mi Band 4 provides excellent battery life that will never leave you wanting for more.

The Mi Band 4 provides excellent battery life that will never leave you wanting for more

On heavier usage patterns, with continuous heart rate monitoring, frequent notifications, lots of walking, and sleep tracking, the Mi Band 4 with its 135mAh battery managed to give me an easy two weeks of use while still having 16% of charge left to spare. On lighter usage scenarios, with the Band 4 spending a lot more time on my desk rather than my wrist, but still vibrating for every call and notification, I managed to get the battery to just about half in two weeks, meaning that the Band 4 could have potentially lasted me for the entire month if I was not too keen on exercising. Between both these scenarios, one can take an educated guess that the Band 4 should be able to handle two weeks of usage between chargings even in very intensive and heavy use scenarios; and just go on forever if you don’t use it much. The freedom to just pick up a device and not have to worry about its battery level is liberating, and whatever magic Xiaomi does with batteries and battery life clearly works even on its smart bands.

You would be glad that the battery lasts this long because charging the Mi Band 4 is one of the few pain points of this otherwise-excellent fitness tracker. As highlighted before in the Design section, the charging cradle is not well designed, and I foresee instances of frustration on this end.


The Xiaomi Mi Band 4 is part of that product lineup from Xiaomi that keeps improving and keeps surprising, year after year. Just when you thought the company has delivered the best value product, out comes another that raises the bar even higher. The Mi Band 4 is an absolute joy to use as a fitness tracker and a smart band, ticking off all the right boxes. Outside of charging, I had no major complaints with this fitness tracker, and I can confidently give it a spot on my wrist every single day.

Xiaomi Mi Band 4 / Xiaomi Mi Smart Band 4

Xiaomi Mi Band 4 XDA Forums

But what truly makes the Mi Band 4 a great fitness tracker is the fact that it manages to do everything without breaking your bank. I purchased the Mi Band 4 on my recent trip to Taiwan, costing me just under $30 (~₹2,150). Mi Bands traditionally target the ₹1,999 (~$28) price tag in India, and the Mi Band 4 might just stick with that trend too.

What truly makes the Mi Band 4 a great fitness tracker is the fact that it manages to do everything without breaking the bank.

At that price, the Mi Band 4 takes fitness tracking from established fitness aficionados who meticulously plan their exercises, to hobbyists and amateurs who are looking for the motivation to get started onto a healthier lifestyle. So if you are looking to get started with a daily run, and think getting a cheap fitness tracker would help, the Mi Band 4’s pricing and its features beyond fitness tracking ensure that you do not feel too bad if you relapse on your decision. The motivation to get fit ultimately comes from within yourself, and the Mi Band 4 just stands on the sidelines cheering you on — it’s an inexpensive decision to make for this role. Had the tracker been more expensive, you would need a stronger motivation, a stronger resolve and a more urgent need to convince yourself that you do need a fitness tracker in your life. And that is Xiaomi’s masterstroke that would help them capture this market for yet another product cycle, deservedly so.

About author

Aamir Siddiqui
Aamir Siddiqui

A journalist at XDA-Developers and the current Editor in Chief, I have been writing for XDA since 2015, despite being a qualified business-litigation lawyer. A low-end smartphone purchase in 2011 brought me to the forums, and it's been a journey filled with custom ROMs ever since. When not fully dipped in smartphone news and tutorials, I love traveling to places just to capture pictures of the sun setting. You can reach out to me at [email protected] And my Twitter is @aamirsidd94.

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