Xiaomi Watch S3 review: The chamelion of smartwatches
Xiaomi Watch S3
Pros
- Highly customizable design for unique style
- Premium build quality and comfortable fit
- Accurate GPS and heart rate tracking
- Long battery life (especially without AOD enabled)
- Great value for the price point
Cons
- Lacks skin temperature, HRV readings
- No external heart rate chest strap compatibility
If you thought smartwatches all looked the same, the Xiaomi Watch S3 is here to challenge that notion. Launched a few weeks ago as an update to the 2022 Watch S2, it stands out from the crowd with its focus on sleek design, impressive build quality, and a unique twist – literally!
This device looks intriguing on paper, with its customisable bezel and the promise of a refined smartwatch experience. But what’s it like in real life? I set out to find out. These are my impressions after about 10 days of testing.
The $150 Xiaomi Watch S3 can be purchased from Xiaomi’s official store.*
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Xiaomi Watch S3 review: Design, hardware
Look & feel: premium build, very customisable
The Xiaomi Watch S3 sheds any notion of being a run-of-the-mill smartwatch the moment you hold it. Crafted from a lightweight yet robust aluminum alloy frame (weighing in at a mere 44 grams), it exudes a quality that belies its price tag. While I tested the sleek silver version, the black iteration offers an equally stylish option.
This is a watch built to last, comfortable enough for all-day wear, and ready to tackle your active lifestyle. Swapping out the included straps is a breeze thanks to the quick-release mechanism, allowing you to personalize the look in seconds for different occasions.
The most eye-catching design element, however, is the interchangeable bezel. With a simple twist and click, you can transform the watch’s appearance. Align a new bezel, and when paired with a fresh strap and watch face from the companion app, the S3 feels like a completely different watch.
This level of customization is a novelty, letting you tailor the device to your tastes. In fact, all the pictures in this review are the same watch, even though in some of them it looks like a totally different timepiece.
The watch’s 1.43-inch AMOLED display is a stunner. Protected by corning glass, it boasts a sharp 466 x 466 resolution, rich colors, and a peak brightness of 600 nits. It delivers exceptional clarity indoors and outdoors. While direct sunlight can slightly dim the view, information remains easily readable thanks to the auto-brightness feature.
Beyond the visuals, the Watch S3 boasts a comfortable, 12mm thin profile that sits neatly on your wrist. Having said that, measuring 47mm, its diameter is quite large. I would therefore consider this to be a masculine watch – less suitable for women and those with small wrists.
In addition to its robustness, the thing is 5ATM water resistant, meaning you can take it swimming or for a jog in the rain without worry. Two flat buttons flank the right side of the watch. The top button acts as a home/back button and a shortcut to the full app list, while the lower button is programmable by default to launch the workout screen. Navigating the watch OS is intuitive: swipe left or right to switch between watch faces, swipe down to access notifications, and swipe up to access settings.
Overall, the Xiaomi Watch S3 punches above its weight in the look and feel department. It’s a device that feels every bit premium and stylish, with the added bonus of extensive customisation options.
Under the hood
The Xiaomi Watch S3 doesn’t just look good; it also packs a punch under the hood. Its array of sensors includes a 12 channel optical heart rate sensor (with 24/7 blood oxygen sensor), accelerometer, gyroscope, geomagnetic sensor and barometric pressure sensor. These enable comprehensive health and fitness tracking. The watch also has a microphone and speakers.
You get the convenience of both Bluetooth 5.2 and Wi-Fi for seamless connection to your smartphone or compatible networks. Plus, there is built-in dual-band GNSS (BeiDou, GPS, GLONASS, Galileo, QZSS) for location tracking of your outdoor workouts. More about the accuracy of this later.
Battery Life: Long lasting, with a caveat
The Watch S3 runs Xiaomi’s HyperOS operating system, designed specifically for the company’s range of products. In fact this is the first smartwatch from the outfit to run on that operating system. The benefit of this lightweight and streamlined software is long battery life.
The Xiaomi Watch S3 is powered by a 486mAh lithium-ion polymer battery, charged using a 2-pin magnetic dock which ends in a USB-A cable. Xiaomi claims up to 15 days on a charge with typical Android use and 14.5 days with iOS. If you opt for the Always-On Display (AOD) feature, expect around 5 days of battery life. In my experience, these figures are largely representative of real-life usage. Unless you enable the AOD, you will rarely need to reach for the charger, making the Watch S3 a reliable companion.
Xiaomi Watch S3 review: Health & fitness tracking
A strong focus, with room to grow
The Xiaomi Watch S3 strikes a balance between sports watch and smartwatch functionality, making it a great choice as a fitness watch. It reliably covers all the essential health tracking basics.
You should really take some time to delve through the settings when you purchase the device. A few options to toggle and tweak. For example, you can set the frequency of heart rate readings between 1 and 30 minute intervals. The higher the frequency the more it will reduce battery life. Or you could set up high and low heart rate alerts.
In my testing, metrics like step counting, sleep tracking, resting heart rate measurements, and blood oxygen levels proved comparable to a high-end Garmin Forerunner on my other wrist. This means you can confidently rely on the Watch S3 to give you an accurate picture of your overall health and fitness baseline.
The Watch S3 pairs with the Mi Fitness app, offering a functional and easy-to-navigate software experience. While slightly lacking in visual flair compared to some competitors, it presents your fitness and health data clearly.
The sleep stats, in particular, are very detailed. In fact Xiaomi has advertised its new and improved sleep analysis algorithm. You also get an overall sleep score along with a “Sleep animal” that represents your style of sleep. We’ve already seen that on Fitbit devices and the Google Pixel watch. This is something similar.
Unfortunately, Xiaomi doesn’t venture far beyond these core metrics. Advanced features like skin temperature tracking and heart rate variability (HRV) monitoring, increasingly found in wearables, are absent here. This feels like a potential missed opportunity to appeal to those more serious about tracking their vitals metrics. That said, what Xiaomi has included works well and delivers the insights you need for a well-rounded health picture.
The timepiece also has your safety in mind! It includes fall detection and emergency assistance features (for Android users). If you fall, it can contact emergency services or a chosen contact, send an SMS for help, and even display important medical information. Set up these potentially life-saving features beforehand using the Mi Fitness app.
The Vitality Score: Exercise motivation
Beyond that, there’s something Xiaomi calls the Vitality Score. Many other brands’ watches have this, but under different naming conventions. The metric is calculated based on your personal details (age, resting heart rate, maximum heart rate) and your workout data over the past 7 days.
The Vitality Score adheres to the World Health Organization’s (WHO) Guidelines on Physical Activity and Sedentary Behavior. These guidelines outline the recommended levels of exercise for optimal health. By tracking your exercise intensity and duration, the Watch S3 can determine how well you’re meeting those recommendations and provide a simple score to keep you motivated.
Think of it as exercise points – the more you move and workout according to WHO recommendations, the higher your score will be. Regularly achieving a weekly Vitality Score target of 100 has proven health benefits. While it might be a fancy term, this score can provide great motivation to stay active.
Xiaomi Watch S3 review: Sports tracking
The Xiaomi Watch S3 boasts the ability to track over 160 different sports activities, with automatic detection for some of the most common ones. As a keen runner, this was the functionality I was most eager to put to the test.
The Watch S3’s GNSS impressed me with its quick connection times. Even in varied terrain, from heavily built-up areas to open spaces, it locked on within seconds – often matching or only slightly trailing my dedicated Garmin running watch. Distance tracking was accurate, with some discrepancies, 300-400 meters over a 10k run compared to the Garmin, when navigating dense urban Central London areas. In open spaces, the accuracy was much better, with almost no differences compared to the Garmin.
What stood out for me was the Watch S3’s heart rate tracking accuracy. Average heart rates and maximum heart rate readings closely mirrored those from my Garmin, typically within 2-3 bpm. This is likely due to the Watch S3’s upgraded heart rate sensor. What’s more, the comfortable, secure fit on the wrist minimizes movement and ensures consistent contact for optimal sensor performance.
While targeted towards a broader audience than hardcore runners, the Xiaomi Watch S3 pleasantly surprised me with its sports tracking capabilities. For regular training runs and even the occasional race, the GPS and heart rate accuracy proved more than sufficient. This, combined with its vast exercise tracking library, makes the Watch S3 a valuable companion for a wide range of workouts.
The Xiaomi Watch S3 is clearly narrowing the gap with dedicated sports watches. While it lacks the ability to connect with external heart rate chest straps, it now offers advanced metrics previously found only on higher-end devices. I was pleased to see accurate VO2 Max estimations (comparable to my Garmin), recovery time guidance, aerobic and anaerobic training effects, and training load insights.
It even provided predicted race times, which were a touch optimistic, but again, this mirrored the sometimes overly-optimistic predictions I receive from my Garmin! So perhaps I am not pushing myself hard enough…
Xiaomi sets itself apart with a unique metric – “Running Ability.” Rather than just providing a single number or score, this feature delves into the different aspects that make up a strong runner.
It analyzes your explosive strength (your ability to generate short bursts of power), aerobic explosive strength (how well you can sustain short bursts of high-intensity exercise under aerobic conditions), anaerobic ability (your capacity for intense exercise bursts without utilizing oxygen), aerobic ability (the efficiency of your body in using oxygen during sustained exercise), general endurance (your ability to maintain exercise over a longer period), and maximum endurance (how long you can sustain maximum effort).
I was pleased to be in the “Advanced athlete” category. Having built up my training over the past 18 months to run marathons, it is where I expected to be.
Xiaomi Watch S3 review: Smartwatch features
Beyond its fitness focus, the Xiaomi Watch S3 delivers solid smartwatch functionality for everyday convenience. Stay connected with incoming notifications from your smartphone. Quickly view text messages, social media updates, call alerts, and calendar reminders right on your wrist.
While you can’t generally interact directly with notifications (like responding to texts), the Watch S3 ensures you’re always in the loop. What you can do is answer and make calls from your connected phone using a built-in microphone and speaker. Chinese models also feature eSim connectivity so you can do this untethered from your smartphone.
The app selection isn’t as robust as something like the Apple Watch or Wear OS devices. You get around 30 built-in apps. And the Xiaomi Watch S3 does offer a selection of third-party apps – but unfortunately none outside of China.
An interesting feature are wrist-based gestures. They offer a quirky way to launch apps like Alexa or reject calls, but the overall functionality is limited.
As mentioned, the vibrant AMOLED display is your canvas to personalize. The extensive selection of watch faces available through the Mi Fitness app offers a plethora of styles. From minimalist designs to data-rich information hubs, there’s a watch face to suit your taste and keep your most important information at a glance.
Finally, you can also control music playback from your smartphone directly on your wrist. Play, pause, skip tracks, or adjust volume during a run or when you’re on the move, leaving your phone tucked away. For even more convenience, you can transfer MP3’s directly to the watch. There’s a total of 2110 MB storage space that can be used for that purpose. The transfer is easily done through the Mi Fitness app.
Xiaomi Watch S3 review: The bottom line
The Xiaomi Watch S3 defies strict categorization. While it isn’t a full-fledged smartwatch and might lack some advanced features for hardcore athletes, it earns its place as a stylish and capable fitness watch. The unique focus on design, with easily interchangeable bezels and extensive watch face options, makes it truly stand out. You can tailor it to your unique style and make it feel like a whole new device with just a few easy adjustments.
The Watch S3 also delivers where it counts. Its premium build, comfortable fit, reliable GPS tracking, accurate heart rate monitoring and detailed performance metrics are sure to please those serious about their athletic pursuits. While the lack of features like skin temperature tracking, HRV monitoring, and external heart rate strap compatibility might be a miss for some, its focus on the core experience delivers a compelling package at its reasonable price point.
If you prioritize style, everyday fitness tracking, and the ability to customize your wearable to match your mood or outfit, the Xiaomi Watch S3 is an appealing and well-rounded choice that won’t break the bank.
The Xiaomi Watch S3 can be purchased from Xiaomi’s official store. It typically retails for around $150. Availability at other retailers should follow soon.*
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No paying ability outside China, I’d assume?
Supports Mastercard payment terminals. Check your region on this link: https://www.mi.com/global/support/nfc-bank
I’m very disappointed with this watch. The worst part for me is the lack of access to apps like WhatsApp and Google Maps. For a watch in this price range, I expected at least some basic app accessibility. While it performs well for simple fitness tracking, it’s frustrating when I receive a notification and can’t interact with it—like replying to a message or even using maps. A watch that costs half as much can manage these basic interactions. I hope future updates will address these limitations. Without access to such simple app interactions, it feels like the watch is missing essential functionality. excluding those the heart beat monitor seems a bit off the sleep tracking seems consistent at times the step counter is ok the work out tracking i expected to be very in-depth such as tracking my sets and reps even if it would be manual would have made a world of difference if its for running and waking it seems ok if ure someone in weight lifting its useless if its for cardio or sports activity seems ok.