Xiaomi Watch S4 Smartwatch Review: Sleek Design Meets Midrange Functionality
The Xiaomi Watch S4 Smartwatch positions itself as a polished, midrange wearable that blends refined aesthetics with core health and lifestyle tracking. At $209.99, it competes in the same arena as the Galaxy Watch 6 and Pixel Watch 2, but takes a different path—prioritizing smooth performance, essential health features, and a classic round watch design without overloading on complexity.
With its 1.43-inch AMOLED display, rotating crown, and lightweight aluminum build, the Watch S4 feels more premium than its price suggests. It runs Xiaomi’s proprietary HyperOS, which enables fast UI navigation, customizable widgets, and reliable Bluetooth calling. It’s not Wear OS, and doesn’t have access to the Google Play Store—but for users looking for speed and simplicity, that tradeoff may be welcome.
Health tracking covers the basics well: continuous heart rate, SpO₂, sleep stages, and over 150 workout modes are included. While GPS performance and app insights aren’t on par with higher-end fitness brands, casual users will find the data sufficient and attractive. Battery life is another highlight, with 5–7 days of typical usage per charge, and fast magnetic charging included.
If you're an Android user looking for a sleek lifestyle watch with reliable fitness tracking, solid battery life, and a non-intrusive interface, the Xiaomi Watch S4 Smartwatch hits a compelling balance—especially if you don’t need third-party app support or advanced training metrics.
MSRP (when available or best estimate): $209.99
Price: Check Price on Amazon
✅ Xiaomi Watch S4 Smartwatch Pros
✅ Refined round design
Lightweight aluminum alloy case with a rotating crown gives the Xiaomi Watch S4 Smartwatch a high-end aesthetic that blends seamlessly into both casual and business settings.
✅ Bright 1.43" AMOLED display
Offers excellent sharpness, color, and smooth 60Hz refresh rate, making it responsive and easy to read in all lighting conditions.
✅ Smooth performance with HyperOS
The proprietary OS feels fast, with fluid navigation, customizable tiles, and minimal lag—even during multitasking.
✅ Reliable Bluetooth calling
Built-in mic and speaker allow clear phone calls from the wrist, with noise cancellation that works surprisingly well in quiet settings.
✅ Solid battery life
Typically lasts 5–7 days per charge depending on usage, and can go even longer in battery saver mode.
✅ Comprehensive fitness tracking
Supports 150+ sport modes, plus heart rate, SpO₂, sleep stages, stress monitoring, and basic workout summaries.
✅ Fast magnetic charging
Goes from 0 to 100% in just over an hour—convenient for users on the go.
✅ Customizable watch faces and widgets
Offers good personalization for users who want to match their look or prioritize certain metrics on-screen.
❌ Xiaomi Watch S4 Smartwatch Cons
❌ No third-party app support
HyperOS doesn’t support apps like Spotify, Google Maps, or Strava, limiting its utility for power users.
❌ Limited ecosystem integration
No syncing with Google Fit, Apple Health, or popular fitness platforms—data stays mostly within the Xiaomi ecosystem.
❌ Inconsistent GPS accuracy
Some users report minor tracking drift during runs or rides, especially in urban environments.
❌ No NFC for payments
Despite a polished design, the lack of contactless payment support limits real-world convenience.
❌ Sleep tracking lacks depth
While it provides duration and stages, insights are minimal compared to Fitbit or Garmin.
❌ Voice assistant support is region-limited
Xiaomi’s XiaoAI is not fully supported outside of China, and there’s no Alexa, Siri, or Google Assistant.
❌ No altimeter or temperature sensor
Lacks environmental tracking common in fitness-first watches at this price.
❌ Companion app (Mi Fitness) feels basic
Offers essential data but lacks the polish and depth of Fitbit or Samsung Health.
Smart Features & Core Tech
Xiaomi Watch S4 Smartwatch
Health & Wellness Sensors
The Xiaomi Watch S4 Smartwatch includes all the expected health tracking tools for its price range. You’ll find continuous heart rate monitoring, blood oxygen saturation (SpO₂), sleep stages, stress monitoring, and all-day activity tracking. While it lacks more advanced metrics like skin temperature, ECG, or HRV readiness scores, the basics are implemented with surprising polish.
Sleep tracking covers duration, light/deep/REM stages, and breathing quality—though users report that insights are relatively surface-level. Heart rate and SpO₂ tracking are consistent during daily use, though accuracy can drop during high-movement activities like HIIT or cycling.
There’s no altimeter or barometer, which limits its appeal for outdoor enthusiasts who track elevation or weather shifts. Still, for everyday wellness and casual fitness, the Xiaomi Watch S4 Smartwatch checks most boxes.
Smart Health Insights
Instead of offering deeply analytical metrics like Garmin or Polar, Xiaomi leans into ease-of-use. The Mi Fitness app provides straightforward summaries—daily steps, heart rate trends, workout duration, and stress levels—without overwhelming users with graphs or jargon.
Over 150 sport modes are supported, including outdoor runs, walking, HIIT, indoor cycling, and yoga. The watch automatically detects some basic workouts and offers customizable fields for exercise display. Post-workout summaries are informative but brief—distance, pace, HR zones, and time, mostly.
Don’t expect VO₂ max estimates, training load, or recovery time. The Xiaomi Watch S4 Smartwatch is more of a smart lifestyle watch than a training tool.
Voice Assistant & Productivity Features
The Xiaomi Watch S4 technically supports XiaoAI, Xiaomi’s proprietary voice assistant—but it’s region-locked to China and not usable on international versions of the watch. There is no built-in support for Alexa, Google Assistant, or Siri voice input.
However, you can manually control some Alexa-enabled smart home devices via your smartphone and Mi Fitness app, meaning limited indirect Alexa integration is possible—just without voice interaction or on-watch execution.
On the productivity side, the Watch S4 handles alarms, weather updates, timers, call logs, and calendar notifications. You can also initiate phone calls via Bluetooth and receive message previews, but can’t respond with voice or type unless using canned replies (Android only).
Display & UX Enhancements
The 1.43" AMOLED display is one of the standout features. It’s bright (up to 600 nits), color-rich, and supports a 60Hz refresh rate, making scrolling and swiping feel smooth. Outdoor readability is good, even under direct sun, and animations are fluid across the board.
Navigation uses a combination of touch gestures and a tactile rotating crown. The crown not only scrolls through menus but can also be pressed to access the app drawer or wake the screen—useful during workouts or with wet fingers.
Watch face customization is broad, with dozens of downloadable options, some with live metrics or themed animations.
Additional Tools & Bonuses
The Xiaomi Watch S4 Smartwatch includes several lifestyle extras:
- Bluetooth calling with noise reduction (dual-mic array)
- Weather, stopwatch, and compass
- Find-my-phone function
- Female health tracking
- Theater and DND modes
- Breathing exercises for stress relief
- 5ATM water resistance for swimming or shower use
While the absence of app store support limits expandability, the out-of-box toolkit covers most daily-use scenarios comfortably.
Performance & User Experience
Xiaomi Watch S4 Smartwatch
Health & Fitness Accuracy
For general lifestyle users, the Xiaomi Watch S4 Smartwatch offers reliable health tracking—especially in areas like step counting, heart rate, and basic workout summaries. The built-in sensors perform consistently in steady-state cardio exercises like walking, treadmill use, and outdoor runs. Heart rate readings tend to stay within ±5 bpm of a chest strap during moderate exertion, though occasional spikes or lags may appear during high-intensity intervals.
Sleep tracking does a good job detecting duration and general stage breakdowns, but the insight level is relatively shallow. You’ll see a basic timeline of light, deep, and REM sleep, but there’s limited guidance on what to do with that data. Nighttime SpO₂ is tracked passively but not deeply analyzed.
Workout tracking is reasonably accurate for indoor and GPS-based activities. Over 150 workout modes are available, but many are simply display labels—the actual metrics reported don’t change drastically between them. Still, the basics—distance, time, heart rate zones, and pace—are clearly presented.
Where accuracy suffers slightly is GPS tracking. The Watch S4 does include onboard GNSS support (GPS, GLONASS, Galileo), but some users report minor drift in high-rise or tree-covered areas. It’s good enough for casual runners, but likely won’t satisfy serious outdoor athletes.
Step tracking tends to err on the generous side, particularly with wrist-based movement during commutes or chores. Stress tracking and blood oxygen readings are average in reliability—neither groundbreaking nor wildly inaccurate.
In short, the Xiaomi Watch S4 Smartwatch is accurate enough for casual fitness tracking and health monitoring, but falls short of the precision and depth offered by more fitness-specialized brands.
Notifications & App Integration
The Xiaomi Watch S4 Smartwatch handles notifications cleanly but with some notable limitations—particularly for iOS users. Paired with an Android device, it can display calls, texts, calendar reminders, and most app alerts (e.g., WhatsApp, Instagram, Gmail) with customizable toggles from the Mi Fitness app. Message previews are crisp and easy to read, thanks to the AMOLED display and large fonts.
Android users also get limited reply functionality via preset responses. There’s no support for custom text input, emoji, or voice reply—everything is canned. Still, for basic acknowledgment or quick replies, it's useful.
iPhone users are more restricted. You can view notifications, but cannot interact with or respond to them in any way. Additionally, syncing reliability can be hit or miss—some iOS users report delayed alerts or dropped connections after longer sessions.
There’s no notification backlog or message history view, so if you miss an alert, it’s gone unless you check your phone. Vibration alerts are strong and adjustable, but there’s no sound or haptic patterns beyond the standard buzz.
As for broader app integration: there is no support for third-party apps. HyperOS is a closed system with no app store or sideloading. You can’t install Spotify, Strava, or even basic utilities like Google Calendar or Google Maps.
In short, the Xiaomi Watch S4 does a good job as a notification reader, especially for Android users. But it’s not built for interaction or ecosystem extensibility—an important distinction for those seeking smartwatch-like productivity.
Smart Assistant & Voice Control
This is one of the Xiaomi Watch S4 Smartwatch’s weakest areas, especially for international users. While the hardware includes a microphone and speaker—used for Bluetooth calling—there is no built-in voice assistant support outside of China.
Xiaomi’s proprietary voice assistant, XiaoAI, is only available on China-region firmware and isn’t functional on global units. Even when accessible, XiaoAI’s language support is limited and doesn’t integrate well with Western ecosystems.
There is no integration with Alexa, Google Assistant, or Siri, and no support for voice commands, dictation, or wake-word activation. This omission puts the Watch S4 behind other lifestyle smartwatches at this price point—like the Fitbit Versa 4 or Huawei Watch GT series—which offer at least basic voice assistant access.
You can still manually control Alexa-enabled devices via your smartphone’s Alexa app while wearing the watch, but this is no different than any standard phone-connected Bluetooth device. The Watch S4 itself cannot trigger routines or respond to voice commands natively.
For users who prioritize hands-free utility—like setting timers, replying to messages, or controlling smart devices—the lack of assistant support is a noticeable gap.
Given the absence of voice functionality altogether, this category earns a default lifestyle rating of 1.5 out of 5.
Battery Life
Battery life is one of the Xiaomi Watch S4 Smartwatch’s strongest selling points. Xiaomi claims up to 10 days of typical use but in real-world scenarios with moderate notifications, heart rate monitoring, and a few workouts per week, users report an average of 5–7 days—which still puts it ahead of many Wear OS competitors.
When used more intensively—with frequent workouts, continuous SpO₂ tracking, and always-on display enabled—battery life shortens to around 3–4 days, which is still respectable considering the 1.43-inch AMOLED screen and 60Hz refresh rate.
There’s also a battery saver mode that disables some background features and can stretch life well beyond a week for minimalist users.
Charging is handled via a magnetic cradle and takes around 75–90 minutes for a full top-up. While not as fast as some competitors, it’s convenient enough to fit into a morning routine or overnight charge.
Notably, the Watch S4 lacks wireless charging or reverse charge support—something a few premium lifestyle watches are beginning to adopt—but that’s forgivable at this price.
Overall, the Xiaomi Watch S4 Smartwatch delivers dependable, upper-tier battery performance in the lifestyle category—especially given its bright display and full-color animations.
Comfort & Design
The Xiaomi Watch S4 Smartwatch stands out for its clean, high-end aesthetic and lightweight construction. With a round aluminum alloy case and polished metal bezel, it strikes a more classic silhouette than the square-bodied smartwatches common in its price range. The rotating crown and side button provide tactile input and subtle flair, while the 1.43-inch AMOLED screen sits flush behind slightly curved glass for a sleek finish.
At just 48g including the strap, the watch feels light on the wrist, even during sleep or workouts. The bundled fluoroelastomer strap is soft, flexible, and breathable—similar to those found on Apple and Samsung watches—and can be swapped for any standard 22mm band, giving users style flexibility.
Despite its elegant looks, the watch is practical. It’s rated 5ATM water resistant, making it safe for showers, rain, and casual swims. The watch fits snugly on smaller wrists, and the side button and crown are well-positioned for right-handed users—though lefties may wish for a flip option in software.
Display quality is a standout: the AMOLED panel is vibrant, crisp, and easily viewable even outdoors. Watch face customization is rich, with dozens of options available via the Mi Fitness app, ranging from minimalist to data-dense layouts.
Overall, the Xiaomi Watch S4 Smartwatch achieves a strong balance between fitness-ready comfort and boardroom-friendly design, making it suitable for all-day wear across a variety of use cases.
Companion App & Ecosystem
The Xiaomi Watch S4 Smartwatch pairs with the Mi Fitness app, a unified platform for syncing health metrics, customizing watch settings, and viewing basic fitness data. The app is clean and well-organized, with tiles for steps, workouts, sleep, stress, and SpO₂—all easily accessible from the home dashboard.
However, the app’s simplicity comes with limitations. Compared to ecosystems like Fitbit, Garmin Connect, or Huawei Health, Mi Fitness offers fewer insights and less historical analysis. You’ll see daily summaries and trends over time, but no in-depth guidance or multi-week training feedback. There’s also no coaching, workout planning, or recovery analytics.
Integration with other services is limited. The app does not natively sync with Google Fit, Apple Health, or Strava, and there’s no support for importing/exporting data to third-party platforms. This creates an ecosystem silo—what you track on the Watch S4 mostly stays within the Mi Fitness app unless you manually export data or use a workaround.
Watch customization is handled well within the app, with dozens of downloadable faces and widget configuration. You can also adjust settings like vibration strength, call handling, app alerts, and workout goals.
Overall, Mi Fitness is functional and clean, but clearly optimized for casual users. Power users looking for multi-platform syncing, advanced metrics, or coaching tools will likely find the experience limiting.
Final Verdict
Xiaomi Watch S4 Smartwatch
The Xiaomi Watch S4 Smartwatch delivers a polished experience for users who prioritize style, battery life, and core tracking features over deep integration and smart productivity. It’s sleek, lightweight, and genuinely attractive—looking far more expensive than its $209.99 price tag would suggest. The rotating crown and AMOLED screen offer a tactile, responsive UI that feels snappy and modern, and its weeklong battery life outpaces many more expensive Wear OS rivals.
But where the Watch S4 excels in physical design, it compromises on software depth. The lack of a voice assistant, app store, or third-party ecosystem ties it firmly into Xiaomi’s walled garden. The Mi Fitness app is adequate for casual wellness monitoring, but fitness-focused users may quickly bump into its limitations—especially the lack of export or sync to Google Fit or Strava.
That said, for users who just want a reliable, attractive watch that handles workouts, calls, and notifications cleanly—and who don't need lifestyle frills like payments or a smart assistant—it lands in a very comfortable sweet spot.
In a market where many watches try to do too much, the Xiaomi Watch S4 Smartwatch sticks to what it knows and executes it well. Just don’t expect it to be your digital butler.
FAQ
Xiaomi Watch S4 Smartwatch
Does the Xiaomi Watch S4 Smartwatch have built-in GPS?
Yes, it supports GPS, Galileo, GLONASS, and Beidou. However, some users report mild tracking drift during runs in urban or wooded areas.
Can I install third-party apps like Spotify or Strava?
No. The Watch S4 runs on Xiaomi’s HyperOS, which does not support third-party apps or offer an app store.
Is there a voice assistant built in?
Not for global users. XiaoAI is technically supported, but it only works in China. Alexa, Google Assistant, and Siri are not available on the watch.
Does the Xiaomi Watch S4 Smartwatch support Bluetooth calling?
Yes. The Watch S4 includes a built-in mic and speaker for making and receiving calls when connected to your phone.
Can I make contactless payments with the Xiaomi Watch S4?
No. There is no NFC chip for mobile payments, so you can’t use it for Google Pay, Mi Pay, or similar services.
How long does the battery last?
On average, 5–7 days with moderate usage. Heavier use (e.g., workouts, always-on display) shortens that to about 3–4 days.
Is the Xiaomi Watch S4 Smartwatch compatible with iPhones?
Yes, but with limited functionality. Notifications work, but you can’t reply, and syncing issues are more common than on Android.
Is the Xiaomi Watch S4 Smartwatch waterproof?
Yes. It has a 5ATM water resistance rating, making it safe for swimming, showering, and light water activities.
Additional Information
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