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I reviewed the Xiaomi Watch S3 in March 2024, and the company launched its successor earlier this year. More recently, they have launched the smaller 41mm version, which has a more feminine design and is better suited for smaller wrists.
Like the previous models, the Xiaomi Watch S4, available in both sizes, utilises Xiaomi HyperOS, making it more of a feature watch than a true smartwatch, similar to WearOS on devices like the OnePlus Watch 3. However, the benefit is a lower price point and excellent battery life.
Most smartwatches, especially these feature watches you get from Xiaomi, Huawei and other brands, have very incremental improvements between generations.
The main difference between the Xiaomi Watch S4 models is the introduction of the new 41mm model. The S4 and S3 adopted a chunkier, more masculine (for lack of a better word) aesthetic, whereas this is a bit more elegant and will appeal to those with smaller wrists who don’t want that oversized watch look.
| Preview | Product | Rating | Price | |
|---|---|---|---|---|
| XIAOMI Watch S4 41mm, Smartwatch, 41mm case diameter,... |
£129.99 | Buy on Amazon | |
| XIAOMI Watch S4 Smartwatch, Fitness Tracker, 1.43 AMOLED, 15... |
£109.99 | Buy on Amazon |
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Xiaomi Watch S3 vs S4 Specification
| Specification | Xiaomi Watch S3 | Xiaomi Watch S4 41mm |
| Dimensions | 47 × 47 × 12 mm | 41.2 × 41.2 × 9.5 mm |
| Weight (without strap) | 44 g | 32 g |
| Display | 1.43″ AMOLED, 466 × 466 pixels, 326 PPI | 1.32″ AMOLED, 466 × 466 pixels, 352 PPI, 60 Hz, 1500 nits HBM |
| Frame / Materials | Aluminium alloy, interchangeable bezels | Stainless steel (Silver, Sunset Gold with lab-grown diamond crown) |
| Straps | Interchangeable (Chrome Yellow, Ocean Blue, Dual-tone Ceramic, Rainbow) | Fluororubber (Black, Mint Green), White leather, Gold Milanese |
| Water Resistance | 5 ATM | 5 ATM |
| Battery Capacity | 486 mAh | 320 mAh |
| Battery Life | Up to 15 days (typical use) | Up to 8 days (light use), 4 days (normal), 3 days (heavy) |
| Charging | 2-pin magnetic charging dock | Magnetic charging dock |
| Operating System | Xiaomi HyperOS | Xiaomi HyperOS |
| Connectivity | Bluetooth 5.2, Dual-band GNSS | Bluetooth 5.4, Dual-band 5-system GNSS |
| Sensors | Heart rate (12-channel) with SpO2, accelerometer, gyroscope, geomagnetic, atmospheric, ambient light, hall sensor | Heart rate (upgraded) with SpO2, accelerometer, gyroscope, ambient light, electronic compass, barometer, temperature sensor |
| Health Features | 24/7 heart rate, SpO2, stress, advanced sleep monitoring, sleep animal insights | Heart rate, SpO2, temperature tracking (skin), improved sleep monitoring with 21-day plan, female cycle prediction |
| Sports Features | 150+ modes, skiing mode, VO2 Max, training load, recovery, 10 running courses | 150+ modes, advanced swimming mode, skiing mode with fall detection, running guide with posture recognition, sports vlog recording (Xiaomi/POCO phones) |
| Safety Features | Gesture controls, wrist movement operations, supports Bluetooth phone calls | Dedicated SOS button, emergency call and location sharing, emergency siren, fall detection (skiing), gesture controls (finger snap) |
| Watch Faces | 180+ watch faces, portrait watch face (with HyperOS devices), bezel-linked dials | 200+ watch faces, interactive Pet Park, customisable widgets |
| Special Design Features | First Xiaomi watch with interchangeable bezels, customisable style | Compact size, slim stainless steel frame, Sunset Gold edition with faceted crown and diamond |
| Compatibility | Android 8.0+, iOS 12.0+ | Works with Mi Fitness app, enhanced with Xiaomi HyperOS 2/3 devices |
Features
Design and Display
The watch is designed for wearability with a compact 41.2mm diameter and a slim 9.5mm profile. It weighs approximately 32 grams without the strap. The middle frame is constructed from stainless steel, available in silver and gold finishes. For the display, it uses a 1.32-inch AMOLED screen. This screen has a resolution of 466 by 466 pixels and a 60 Hz refresh rate, capable of reaching 1500 nits of brightness in high brightness mode for clear visibility. A variety of strap materials are available, including fluororubber, leather, and a Milanese option. Users can personalise the device with a choice of over 200 watch faces.
Health and Wellness Monitoring
The device includes an upgraded heart rate module that also measures blood oxygen levels. An innovative skin temperature sensor is incorporated, which provides data for enhanced female cycle prediction, detects abnormal skin temperatures, and can issue overheating alerts. Sleep tracking capabilities are also upgraded, offering multi-dimensional insights and a 21-day guided plan for sleep improvement.
Fitness and Activity Tracking
For fitness enthusiasts, the watch supports over 150 sports modes. It features a dual-band five-system GNSS for precise outdoor positioning during activities like running. It provides professional modes for specific sports, including an advanced swimming mode and a professional skiing mode that includes fall detection. The watch also offers a comprehensive running guide and posture recognition. Data can be shared with external platforms such as Suunto, Strava, and Health Connect. A sports vlog function allows users to control a connected Xiaomi smartphone to record video during workouts.
Performance, Safety, and Smart Features
Powered by Xiaomi HyperOS, the watch offers a smooth user interface with customisable widgets and navigation via a rotating crown. The 320mAh battery supports up to 8 days of light use. For connectivity, it uses Bluetooth 5.4. Safety is addressed with a dedicated SOS button that enables quick emergency calls and shares real-time location. For smart interactions, the watch supports NFC payments and customisable finger snap gestures for quick access to functions like rejecting calls or opening applications.
Unboxing / Design
The first impression is that the watch feels premium despite its size. The stainless steel frame provides a polished look, and it is surprisingly lightweight at just 32 grams minus the strap.
The display is protected with a flat glass panel and has a subtle crown, alongside a push button for power and quick actions.
The band is 18mm wide, soft, and comfortable. Replacement is easy thanks to a quick-release feature. My review sample was in the default white colour, but there are black and mint green options, plus a fancier Sunset Gold version for those wanting a dressier look. The strap feel well-made, and the Milanese gold option looks to be especially suited for more formal occasions.
The S4 41mm measures 41.2 x 41.2 x 9.5 mm. It has a notably slim profile compared to mainstream sports watches, making it ideal for those with slender wrists. Xiaomi has kept the aesthetic minimal, which suits both men and women depending on strap choice. I found it discrete and comfortable during all types of wear, including overnight sleep tracking.
Display wise, Xiaomi equips the S4 41mm with a 1.32-inch AMOLED panel. The 466 x 466 pixel resolution is above average for this size, leading to excellent pixel density, sharp menus and clear notifications. Colours are punchy, and the 60 Hz refresh rate gives smooth navigation. All menus and content are easily readable, even for users who might struggle with small screens.
Brightness, at 1500 nits, is sufficient for legibility in strong sunlight, and the Always-on Display is well executed, adopting a simple analogue clock design. In my experience, it beats cheaper LCD watches and is very close to Huawei’s GT-series in display quality.
The frame is stainless steel, adding robustness and style, and I have found it resists scratches well through daily use. Button feel is crisp, and the rotating crown works for scrolling and quick access throughout menus.
Set Up
Setting up the Xiaomi Watch S4 is a standard process for modern wearables. The watch is compatible with both Android (8.0 and above) and iOS (12.0 and above) devices. To begin, users need to download the Mi Fitness app from their respective app store. The app guides you through the pairing process, which uses Bluetooth to connect the watch to the smartphone. Once connected, the watch syncs data with the phone, and users can begin customising settings, watch faces, and notification preferences directly from the app. For users with Xiaomi phones running HyperOS 2 or 3, the integration is enhanced, allowing for a more seamless experience with features like the portrait watch face and sports vlog recording.
Health Tracking
Xiaomi has packed the S4 41mm with an upgraded heart rate sensor, incorporating both SpO2 and skin temperature monitoring. During daily exercise and sleep, I found accuracy to be reliably within 1 bpm of a Polar chest strap and just as consistent with Coros during yoga sessions. The watch has also been tuned for female cycle prediction, using skin temperature data, though thorough testing of this feature would require longer-term use.
The checkup feature gives a one-minute readout of SpO2, heart rate, stress and sleep quality, which a nice convenience feature. Sleep tracking is solid, with staging that closely matches my Garmin, generally within 15 minutes’ variance for night totals. It also provides a 21-day guided sleep plan intended to help users form better habits, though this is only useful if you are committed to daily logging and feedback. For stress tracking, I found results to be broadly in line with competitor watches, usually pegged to heart rate and movement patterns.
There are some differences between the Xiaomi and my Garmin for things like sleep. My Garmin has a sleep coach, sleep factors and some basic feedback. The sleep coach provides some insightful information for your current sleep needs. But Xiaomi also breaks down your sleep into stages and then provides a bit more detail in the interpretation. You can then start a sleep improvement plan, which tries to guide you through ways to improve your sleep over 7 days.
Fitness Tracking
After years of wearing a Garmin, I refuse to give up on wearing a Garmin, as I want all my fitness data in one place. So, during my review period, I wore the Xiaomi on one arm and my Fenix Epix Gen 2 on the other. I swapped wrists every day just to make sure the results were consistent.
One thing I immediately noticed was that the Xiaomi locked onto GPS faster. I don’t have the Epix Gen 2 Pro, so the Xiaomi has a slight advantage with the dual-band 5-system GNSS. GPS lock typically took 3-5 seconds, which is genuinely impressive. Even in areas with tall buildings where GPS usually struggles, the watch maintained accurate tracking.
I found the fitness tracking to be excellent – the GPS track aligned well with the Garmin, and the heart rate tracking was similarly accurate. Though, as with all wrist-based heart rate monitoring, it can be prone to inaccuracies. I actually find my Garmin more prone to inaccuracies during high-intensity intervals.
The watch provides useful metrics during activities, including elevation gain/loss, cadence, stride length, training effect, and VO2 Max estimates. A few years ago, that would have been excellent, but many brands have replicated the features found on Garmin and now include more advanced metrics like running power and cycling power. The Xiaomi S4 doesn’t offer these advanced metrics, which is disappointing but understandable at this price point.
Auto-detection for workouts works reliably. If you start running without manually triggering a workout, the watch will notice and ask if you want to start tracking. This works for walking, running, and cycling in my experience.
The swimming mode tracks laps, stroke type, and SWOLF scores. The 5 ATM water resistance rating means it’s suitable for swimming, though I’d avoid deep diving or high-pressure water sports. I tested it in the pool, and tracking seemed accurate for lap counting.
Data export to Strava worked seamlessly. Activities appeared in Strava within minutes of finishing and syncing. The integration also works with Suunto and Health Connect, which gives you flexibility in how you manage your fitness data.
Smart Watch Features
The HyperOS interface is clean and responsive. Swiping up from the watch face shows notifications, swiping down accesses quick settings, and swiping left or right cycles through widgets. The rotating crown provides an alternative navigation method that feels precise.
Notifications work well with both Android and iPhone. You can read messages, view emails, and see app notifications. Quick replies aren’t available for most messaging apps, but you can use preset responses for rejecting calls. Call handling is straightforward – the watch has a speaker and microphone for Bluetooth calls. Audio quality is acceptable for brief conversations, though you wouldn’t want to conduct a lengthy call through the watch.
Music controls work as expected, allowing you to play, pause, skip tracks, and adjust volume on your connected phone. There’s no onboard music storage, so you’ll need your phone nearby.
The watch faces deserve mention. The default selection is varied, from simple analogue designs to complex digital faces packed with information. You can customise complications on many faces to show the data you want at a glance. The interactive Pet Park watch face is a quirky addition – you raise a virtual pet that moves around your watch face. It’s not particularly useful, but it’s fun.
Weather information is displayed clearly, pulling data from your phone. You get current conditions and a multi-day forecast. The compass works reliably once calibrated, and there’s a flashlight function that turns the screen bright white, useful for finding things in the dark.
Battery Life
The 41mm model has a battery capacity of 320mAh vs 486mAh on the standard 47mm model.
Xiaomi claims the normal S4 can achieve 15 days of typical use. With the 41mm model, they are more precise; they claim 8 days for light usage, 4 days for normal use and 3 days for heavy use.
The quoted numbers don’t look favourable for the 41mm model. You have a battery that is 34% smaller, but a battery life that is likely less than half. Obviously, the display plays a part in this; the 1.32-inch display is only 7.69% smaller than the 1.43-inch display.
I did some quick napkin maths, and a very rough guess is that the battery life should be about 23% shorter battery life compared with the 486 mAh model.
In terms of real-world usage, I got around 4 days. I would say that my usage was a bit more than normal. I didn’t use the smart watch features much, but I did use GPS a lot and had all the features enabled.
Price and Alternative Options
| Preview | Product | Rating | Price | |
|---|---|---|---|---|
|
| XIAOMI Watch S4 41mm, Smartwatch, 41mm case diameter,... |
£129.99 | Buy on Amazon | |
|
| XIAOMI Watch S4 Smartwatch, Fitness Tracker, 1.43 AMOLED, 15... |
£109.99 | Buy on Amazon |
The Xiaomi Watch S4 41mm has an RRP of £130 and is available from Mi.com for £120.
The larger Xiaomi Watch S4 has been out since March and is available for £110. I would hope that in a few months, the 41mm will be available for the same price.
Xiaomi also has the Watch 2, which is a WearOS watch that is the same price at £120. It is not really comparable due to the aesthetic and underlying OS, but it is certainly worth considering if you are looking for a proper smartwatch.
Huawei just launched the Watch GT6, and they have a 41mm model that has a considerably higher RRP of £230. The much higher price point is justified as it appears to be a superior watch, including better fitness features, including mapping features and cycling power, plus a much longer battery life.
OnePlus also recently launched the 43mm model of the OnePlus Watch 3, which has a RRP of £270 but is discounted to £230. This is a fully fledged smartwatch with WearOS, but unlike many other WearOS watches, it has a fantastic battery life, and I’d probably buy this over the Watch GT6, considering the matching price point.
If you were to go with Garmin, the Venu 4 41mm is the best alternative, which is priced significantly higher at £470. It is vastly superior for fitness tracking, but the aesthetic is a little bland compared to the above options, and it is hard to recommend to anyone other than those seriously into fitness.
Overall
I have been a fan of Xiaomi watches for several years now. As a fitness enthusiast, they won me over with the Strava integration, which they implemented long before Huawei and some other brands.
The fact that they are not fully fledged smartwatches means the battery life has always been excellent, which is a major factor for me, and the pricing has been very attractive.
Admittedly, they haven’t convinced me to ditch my Garmin, but I consistently recommend them to friends getting into fitness who want a semi-decent watch to track activities, or just those wanting an affordable smartwatch that looks more premium than a fitness band.
As for the Xiaomi Watch S4 41mm, it continues the trend of great watches. The main selling point here is the overall aesthetic; it will appeal to more buyers than previous generations, which were limited to just one size.
While the watch is a bit too small for my tastes, my partner likes it, which confirms the above.
The S4 models don’t introduce much more than was on offer on the S3, certainly not enough to justify the upgrade from S3 to S4. In the case of this watch, I don’t think that is an issue.
The fitness tracking is solid, with accurate GPS and heart rate monitoring that matches or exceeds what you’d expect at this price point. The dual-band GNSS is a standout feature that you usually only see on more expensive watches. Health monitoring features cover the basics well, and the sleep tracking provides useful insights.
My one minor gripe is that the battery life is noticeably smaller than previous generations. I got around 4 days of use, which is fine and unavailable due to the smaller design, but it makes a big difference compared to the 10+ days I got on the larger S3.
The lack of advanced fitness metrics like running power or training readiness might disappoint serious athletes, but for casual fitness enthusiasts, the metrics provided are more than adequate. The watch does what it needs to do without overwhelming you with data.
At £120, the Xiaomi Watch S4 41mm offers good value. It’s not the best watch in every category – Garmin beats it for fitness tracking, WearOS watches offer more app flexibility, and Huawei’s GT6 has longer battery life. But the combination of design, features, and price makes it a sensible choice for many users.
Overall, if the design appeals to you and you want a capable fitness tracker with smartwatch features that doesn’t cost £300+, then I can recommend the Xiaomi Watch S4 41mm. Just don’t expect it to replace a dedicated sports watch if you’re training for marathons, and be prepared to charge it more frequently than you might like.
Xiaomi Watch S4 41mm Review
Summary
The Xiaomi Watch S4 41mm is a stylish and compact smartwatch alternative that balances fitness tracking, health monitoring, and everyday convenience at a very competitive price. Its design makes it well-suited to smaller wrists, and it delivers accurate GPS and heart rate tracking, though the shorter battery life compared with the larger model is noticeable. It is not a replacement for a high-end sports watch, but for casual fitness enthusiasts or anyone seeking a premium-looking wearable without a high price tag, it offers excellent value.
Overall
90%-
Overall - 90%90%
Pros
Compact, lightweight and premium stainless steel design
Accurate dual-band GNSS with quick GPS lock
Reliable health and sleep tracking features
Good value for money
Cons
Shorter battery life than the larger model
Limited advanced fitness metrics
Lacks third-party app support compared with WearO
I am James, a UK-based tech enthusiast and the Editor and Owner of Mighty Gadget, which I’ve proudly run since 2007. Passionate about all things technology, my expertise spans from computers and networking to mobile, wearables, and smart home devices.
As a fitness fanatic who loves running and cycling, I also have a keen interest in fitness-related technology, and I take every opportunity to cover this niche on my blog. My diverse interests allow me to bring a unique perspective to tech blogging, merging lifestyle, fitness, and the latest tech trends.
In my academic pursuits, I earned a BSc in Information Systems Design from UCLAN, before advancing my learning with a Master’s Degree in Computing. This advanced study also included Cisco CCNA accreditation, further demonstrating my commitment to understanding and staying ahead of the technology curve.
I’m proud to share that Vuelio has consistently ranked Mighty Gadget as one of the top technology blogs in the UK. With my dedication to technology and drive to share my insights, I aim to continue providing my readers with engaging and informative content.
Last update on 2025-10-10 / Affiliate links / Images from Amazon Product Advertising API
