Xiaomi Mi Band 1S (Review)

Written by Adrin S

When Xiaomi released the Mi Band just over two years ago, it turned the market for personal fitness trackers on its head. Suddenly for the first time, people could buy a fitness tracker for less than $20. The Mi Band made wearable fitness trackers accessible to the masses and ushered in the era of affordable fitness wearables backed mostly by other Chinese manufacturers.


Two years after its release, the Mi Band now has a successor — the more advanced Mi Band 2 but still continues selling well thanks in part to its highly affordable price tag and reliability. It has also undergone an update, in the form of the Mi Band 1S which features a heart rate sensor. The Mi Band 1S is about as basic as it gets with fitness trackers. You can track how many steps you take each day, know how well you sleep at night and also take your heart rate at any time (the original Mi Band did not have an HR sensor).

Xiaomi Mi Band 1S Highlights
  • Magnesium-aluminum alloy casing
  • Band material: TPSiV
  • Battery capacity: 45mAh (10 to 30 days standby)
  • Waterproof rating: IP67
  • Bluetooth 4.0 compatible
  • Android 4.4 / iOS 7 or higher required for Mi Fit app
  • Heart rate and motion sensors

With the Mi Band 1S (let’s call it 1S for short), there is no LCD display. To configure it or view recorded data, you need to install the Mi Fit app on your smartphone. The built-in 45mAh battery gives a decent 4 weeks of use before it needs to be recharged (if you don’t use its vibration alert feature extensively). Use its vibrator often, and the 1S will give about two weeks of service before it needs a recharge.


Sleep and Activity Tracking

The band tracks your movements using a motion sensor which detects how many steps you take or how long you stay still. The more steps you take, it is assumed the more active you are. Sleep is tracked when your wrist shows little to no movement at all and sleep data is divided into light sleep and deep sleep. When your wrist stops moving for a prolonged period of time, the 1S assumes that you’re having deep (REM) sleep and tracks it as such.

Although this is not exactly the most accurate way of detecting REM sleep (the band has no way of detecting if your eyes are moving while closed and other signs like that), it sure works quite well. Very often, when my sleep data shows a solid 1 hour of REM sleep the previous night, I actually feel very refreshed the next day. When only 10 minutes or less of REM sleep is recorded (due mostly to sleep interruptions at night), I generally feel a bit lethargic the next day. As a “sleep tracker” that costs less than $20, the Mi Band 1S is simply great value.

It doesn’t disappoint as a fitness tracker as well although sometimes the motion sensor does get fooled by certain movements that it sees as “steps”. For example, you can take a bus that’s traveling along a bumpy road and the 1S will detect all those bumps as steps even though you’re sitting all the time.

Heart Rate Monitor

Another interesting feature on the Mi Band 1S is the heart rate sensor. The 1S, like many other cheap fitness trackers that feature HR sensors in the market today, have a built-in optical sensor that detects blood flow underneath your skin which is then translated as how fast your heart is beating. The 1S takes about 10 seconds to measure this blood flow and comes up with a heart rate each time you request a reading.


Although the HR sensor works well, it is not a substitute for a real heart rate monitor like the kind you’d get with Polar or Garmin devices that feature HR readings. The HR feature on the 1S does not give you real-time HR readings. This means each time you need an HR reading, you have wait a while for it to perform a reading before you see a figure. This is not something you want if you’re a serious athlete who needs a constant HR reading that updates itself every few seconds or so during a training session.

The HR feature on the 1S will probably work well if you’re just looking to get a resting pulse when you wake up in the morning or at any other time of the day. Just don’t expect to give you much insight into your HR during an exercise session.


As a fitness tracker, the Xiaomi Mi Band 1S offers plenty of value. Costing less than $20, it surprised me with its quality and reliability. I’ve not had any reliability or quality issues with the 1S since I got it. Battery life is also decent if you don’t overuse the vibration alerts. The heart rate sensor is definitely a key selling feature but if you’re a serious athlete looking for accurate real-time HR monitoring during training sessions, then this device is not for you. As an entry level fitness tracker, the 1S doesn’t disappoint. It’s a great buy if you need something basic without the extra bells and whistles you get in more expensive trackers. If you’re interested in getting one, GearBest has it for $12.79.

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Adrin S

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