Xiaomi’s smartwatch game has steadily evolved since the first Mi Watch came on the scene in 2019. We’ve seen various Xiaomi wearables since – some with simple proprietary operating systems that have changed names more than features, and some with Google’s more capable, but power-hungry WearOS. Xiaomi Watch S3 is the first smartwatch from the brand to launch with HyperOS, the maker’s in-house operating system that powers numerous other devices including IoT appliances and the maker’s SU7 electric car.
Watch S3 brings everything you need in a smartwatch – a bright and crisp AMOLED screen, a standard mix of health and activity tracking, GNSS positioning, NFC payments, and the ability to take calls from your wrist. It’s also highly customizable with interchangeable watch bezels and straps, allowing you to adapt the watch to your style.
At €150/£130 in Europe, Xiaomi is positioning Watch S3 as its go-to smartwatch for 2024, and we’ve spent the last two weeks testing it out.
Xiaomi Watch S3 specifications
- Display: 1.43″ AMOLED touchscreen, 466 x 466 px resolution, 60Hz refresh rate, 600 nits peak brightness
- Straps: Detachable straps, 22mm width, 140-210mm adjustable length
- Features: 5ATM rating, Real-time heart rate monitor, 24/7 Blood Oxygen level monitor, Sleep tracking, Stress monitoring, Sports tracking, VO2 Max, Step Counter, Meditation, Notifications, Idle Alert, Phone Finder, Weather Forecast, Music and Camera Control, Recorder, Alarm, Stopwatch, Compass, Barometer, Flashlight
- Sports Modes: Outdoor Run, Indoor Run, Outdoor Walk, Outdoor Cycle, Hiking, Strength Training, Jump rope, Freestyle (150+ more in Mi Fitness app)
- Sensors: 12-channel PPG optical heart rate sensor, SpO2 sensor, 3-axis accelerometer, barometer, rotor Vibration Motor
- Connectivity: Bluetooth 5.2, Compatible with Android 8.0 and iOS 12+, dual-band L1+L5 GNSS, NFC (market dependent), microphone and speakers
- Battery: 486 mAh
- Colors: Black, Silver
- Dimensions: 47 x 47 x 12 mm
- Weight: 44 grams without strap
Design
Watch S3 brings a familiar design that falls in line with the Xiaomi Watch 2 generation. It’s a large watch with a 47mm casing and a 1.43-inch AMOLED screen, which certainly takes some getting used to if you’re coming from a smaller watch or smartband. The big new addition to the Watch S3 is the stainless steel bezel, which is detachable and allows for unparalleled customization options.
A quick counterclockwise twist and turn detaches the bezel and frees up the watch to take in any of the four additional styles, which we only presume will grow in number from here. The bayonet mount, like you’d find on a camera lens, is a neat design choice that locks in securely. Each watch bezel comes with its watch face, which immediately toggles on when attached.
The interchangeable bezels, coupled with the endless option of 22mm watch bands, enable unprecedented customization, a great way to give new life to the watch down the line. Sadly, the bezel is just for looks and doesn’t add any functionality like you’d get on a Galaxy Watch6 Classic and its rotating bezel. Our silver Watch S3 review unit comes bundled with a matching stainless steel watch bezel and silver fluoro rubber watch strap.
Watch S3 feels as premium as the more expensive smartwatches we’ve tested, with its sleek aluminum frame, stainless steel watch bezels, and the plethora of 22mm watch strap options. Despite the large form factor, it somehow feels light and unobtrusive on the wrist, weighing 44 grams without the strap and 12mm thick. It’s also 5ATM waterproof, so swimming sessions are a go.
The 1.43-inch AMOLED display offers saturated colors and great viewing angles. It gets bright enough for outdoor use, maxing out at 600 nits of peak brightness and also features a dedicated auto-brightness sensor. The display refreshes at 60Hz, making it feel snappy, and it’s protected by Gorilla Glass 3. Some of the always-on display options are harder to see in direct sunlight.
There are two buttons for navigation, with the top one acting as a shortcut to the app menu while also doubling as a back button, while the bottom one is programmable and can be paired to launch any app but acts as a shortcut to the workout page by default.
Despite its aluminum alloy frame and stainless steel bezel, Xiaomi Watch S3 weighs 44 grams, which doesn’t feel heavy on the wrist and is comfortable to wear all day long. The retail box features the Watch S3, its proprietary two-pin magnetic charging puck which ends in a USB-A cable, and the usual mix of manuals. Wireless charging seems to be the only omission.
Features
Xiaomi Watch S3 packs a long spec sheet with one of its key features being HyperOS. Xiaomi’s proprietary IoT platform looks familiar to MIUI Watch, but sadly does not support third-party apps outside of China.
There are 31 built-in apps including Amazon Alexa, a phone dialer, a voice recorder, an NFC cards app alongside all of the usual set of apps you’d find on a smartwatch like an alarm, a detailed weather app, as well as health and activity tracking apps. You also get reminders, calendar, contacts, media controls, breathing exercises, a barometer, compass, flashlight, and a camera shutter.
Watch S3 features a microphone and speaker allowing you to make and take calls from your paired phone over Bluetooth. Our review unit does not feature eSIM connectivity, though Chinese versions do, gaining total independence from your phone. Xiaomi is also offering push notifications on the watch for most apps, but these are usually just simple alerts without the option to reply or take any additional actions.
There are two vibration settings with standard and strong values. In addition to the two physical buttons, Xiaomi added quick gestures, a gimmicky way to launch additional apps by tilting your wrist 90 degrees or performing a circular motion. Options are limited here with support for summoning Amazon Alexa, the weather app, rejecting incoming calls, and triggering the remote camera shutter function on your paired phone.
Watch S3 also supports dual-band (L1 and L5) satellite positioning over BeiDou, GPS, GLONASS, Galileo, and QZSS as well as NFC payments through Xiaomi Pay. The caveat with payments is that you can only add Mastercard-issued cards and pay at Mastercard payment terminals.
On the health tracking side, Watch S3 features a 12-channel heart rate sensor with 24/7 heart rate monitoring, SpO2 tracking, stress, and sleep tracking with an updated new sleep algorithm offering REM sleep and breathing scores.
Xiaomi’s Mi Fitness app is one mandatory installation you’ll need on your paired phone to toggle most of the functions on the Watch S3. The watch supports a total of 161 workout modes covering just about every activity you could think of from running and weightlifting to nuanced activities like kite flying and board games.
You have access to the full list of activities within the Workouts app on the watch, which is neat, and Mi Fitness can keep up to a month’s worth of health and workout data. You can also sync your health and activity data with Apple Health, Google Fit, Strava, and Suunto.
There are 13 pre-loaded watch faces with varying levels of customizable elements for watch complications and accent colors. You’ll find a great selection of additional watch faces within the Mi Fitness app too.
Watch S3 also comes with fall detection and emergency assistance functions, though they are limited to Android users. These include the ability to call emergency services or an emergency contact of your choosing and send out an SMS message in the event of a fall. You can also store your key medical data on the watch, which will be displayed when you trigger the emergency assistance feature. Keep in mind that these settings need to be configured within the Mi Fitness app on your phone beforehand.
Software and Performance
While its naming is new, HyperOS did not offer any tangible differences over previous non-Wear OS Xiaomi watches during our testing. The app icons and menus have received a new coat of paint, but that’s about it. Xiaomi says that HyperOS will allow for more seamless connectivity and integration between its devices down the line, but for now, it’s mostly the same thing under a new name.
While Google’s WearOS offers extensive third-party app support and savvier smartphone replacement skills, a watch like the S3 with HyperOS is preferable if you just want to cover the basics of a smartwatch while also getting great battery life. Apart from a dedicated maps app and the option to reply to notifications, I did not feel I was missing any functionality on the Watch S3 during my review period.
The UI is simple and runs without any noticeable lag. You can interact with the watch in a few ways – by double-tapping the screen, raising your wrist, or by pushing either of the side buttons. From there, you can swipe down for notifications, or swipe up from the bottom to toggle the control center page.
Swiping left or right gives you access to your widgets, which are cards of apps bundled together. You can configure up to four apps in a single widget card directly from the watch or within the widgets tab on the Mi Fitness app. Notifications on the Watch S3 come promptly, but we already covered the lack of any additional functionality as you can only dismiss them.
The onboard speaker does the job, but it’s a bit hard to listen to during calls in noisier environments. The microphone handles voice pickup well, with people on the other end of calls reporting loud and clear reception on my part. The watch kept a stable connection to my paired iPhone 15 Pro throughout the review period with no drops.
Health Tracking
Watch S3 supports configurable heart rate tracking via a 12-channel PPG optical heart rate sensor. You can configure the readings between 1 and 30-minute intervals, with the shorter values eating up more of your battery life. Heart rate readings were on par with other recently tested smartwatches. You can also set high and low heart rate alerts, with alerts appearing once you’ve passed or dropped below a predetermined threshold.
Blood oxygen tracking (SpO2) is also supported with 24/7 readings. In terms of accuracy, we found both the heart rate and SpO2 results offer similar values to what you’d get on competing smartwatches and other health trackers like dedicated pulse oximeters. Don’t expect medical-grade readings here as wearables like this are meant for tracking your general well-being. We compared the heart rate and blood oxygen measurements from the watch with those from a specialized heart rate monitor and pulse oximeter and got similar values.
Xiaomi is advertising its new sleep analyzing algorithm with claims of improved accuracy, and we can confirm it does a great job of logging accurate go-to-sleep and wake-up times. You get a detailed breakdown of your sleep by category with deep, light, and rapid eye movement (REM) sleep. Wearing the Watch S3 for a week will generate your own personal sleep insight report with an assigned sleeping animal based on your sleeping pattern, as well as a recommended schedule on how to set your day for optimal rest and recovery.
I did experience a bug with a few random additional awake times added to some sleeping sessions, even though I was in bed and did not get up at all during those nights. Hopefully, Xiaomi can fix this with future
Source: GSMArena