Xiaomi Watch S4 41mm review: Beautiful smart watch at a reasonable price

When Xiaomi introduced the Watch S4 with its robust 47mm case in spring 2025, it was an instant hit. Solid battery life, decent performance, and a premium look attracted thousands of customers. However, not everyone has room on their wrist for a watch that looks like a cockpit instrument from a fighter jet. And that’s precisely why we have the Xiaomi Watch S4 41mm – a more elegant, lighter, and significantly more refined variant that the brand introduced alongside the Xiaomi 15T series.

The smaller version is primarily aimed at people with narrower wrists, which in practice mainly means women. But Xiaomi made a smart decision – instead of a sporty design, it opted for elegant minimalism with premium materials, so the watch doesn’t look like a miniature fitness tracker, but like a real piece of jewelry. And the Sunset Gold edition with a diamond in the crown? That’s the icing on the cake that few expected. Our Svět Androida editorial team tested the more understated black version, which also looks good and certainly won’t go unnoticed on the wrist.

Moreover, beneath the elegant surface lies solid hardware with an AMOLED display, dual GNSS, continuous skin temperature measurement, and a plethora of sports modes. The battery lasts up to 8 days, and new safety assistance with an SOS button has also been added.

Design and Craftsmanship: 32 Grams of Elegance with a Diamond

The Watch S4 41mm has a diameter of 41.2 mm and a thickness of 9.5 mm, which is significantly more compact than the standard 47mm version. A weight of 32 grams without the strap means you barely feel the watch on your wrist – something especially appreciated by people who dislike heavy watches. The case is made of stainless steel with a glossy finish, which looks premium but is quite prone to fingerprints.

Xiaomi offers four color variants. The basic black and mint green come with a fluoroelastomer strap with a woven texture – soft, non-slip, and suitable for sports. I must say it’s very comfortable to the touch and for everyday wear. The white variant has a leather strap for a more elegant look. And then there’s the star of the entire collection – Sunset Gold with a gold Milanese strap and a lab-grown diamond in the crown.

Yes, you read that correctly – a real diamond is set in the crown. Xiaomi states that it’s a “lab-grown” stone, which is a modern technology allowing a real diamond to be produced without mining. Is it a marketing ploy or truly added value? It depends on your perspective. The fact remains that the crown looks luxurious and has a faceted surface that sparkles at the right angle of light.

The craftsmanship is excellent. The buttons have a pleasant response, the crown rotates smoothly, and the entire watch feels solid. 5 ATM water resistance means it can withstand a shower, swimming in a pool, or even waves at sea. However, you shouldn’t take them into a sauna or under a hot shower.

Display: A Bright Circle That Won’t Disappear in the Sun

The display has a diagonal of 1.32 inches in a circular design with a resolution of 466 × 466 pixels, resulting in a density of 352 ppi. This is sharp enough for text to appear legible and icons to have smooth edges. The AMOLED panel offers vibrant colors and deep blacks.

A maximum brightness of 1,500 nits in HBM mode (High Brightness Mode) ensures readability even in direct sunlight. In practice, this works reliably – the display remains visible even during outdoor sports activities. The 60 Hz refresh rate is better than cheaper watches, which often only have 30 Hz displays. Animations are smooth and touch response is instantaneous.

Xiaomi has prepared over 200 watch faces, including interactive ones with virtual pets. The funniest is a capybara trying to balance oranges on its head – silly, but amusing. Gamification works by having your daily movement determine how quickly the pet grows. It’s a small detail, but it can motivate greater activity.

The Always-on display is available, but it logically consumes battery. Xiaomi handles this cleverly – you can set a time window for when AOD should be active, and it turns off outside of that. Practical if you only want the watch active during working hours, for example.

Hardware and Sensors: Improved Measurement with a New Module

The Watch S4 41mm features an improved heart rate module with 4-LED and 4-PD sensors, which, according to Xiaomi, ensures higher accuracy and stability of measurement even during intense movement. In practice, this means the watch can measure heart rate in real-time even while swimming, which will be especially appreciated by swimmers who want to monitor their exertion in the water.

A new feature is continuous skin temperature measurement using a highly accurate contact sensor. The watch can detect changes as small as 0.1 °C and alert to abnormal temperature increases – for example, during a fever. For women, this function has another significance: in combination with menstrual history data, it can more accurately predict the female cycle, including ovulation days and fertile periods.

GPS here is dual GNSS with L1 and L5 frequency support, which means accurate location tracking even in urban areas or dense forests. The system supports five satellite systems (GPS, Galileo, GLONASS, BeiDou, QZSS).

Other sensors include an accelerometer, gyroscope, compass, barometer, ambient light, and digital thermometer. This is a solid set of features that covers all basic and advanced functionalities.

Health Features: Comprehensive Monitoring with Practical Tips

The Watch S4 41mm offers all-day monitoring of heart rate, blood oxygen saturation (SpO2), stress levels, and of course, advanced sleep tracking. The latter has undergone significant improvement – the watch not only analyzes sleep phases but also offers a 21-day plan to improve sleep habits developed in collaboration with international sleep experts.

The plan includes optimizing sleep patterns, managing daytime naps, recommendations for evening activity, and relaxation before bedtime.

The Health Check-up feature allows you to get a quick overview of your health status with a single tap – heart rate, SpO2, sleep quality, stress level. However, all these functions must be manually enabled in the settings.

Fitness and Sport: 150+ Modes for Every Activity

The watch supports over 150 sports modes, covering practically anything – from running, swimming, and cycling to yoga, skiing, or even diving.

Skiers will appreciate fall detection. If the watch registers a hard impact and subsequently no movement for 60 seconds, it automatically triggers an alarm and, after another minute, initiates an emergency call to a pre-set contact. The function requires a Bluetooth connection to the phone (as they don’t have LTE connectivity), but in a critical situation, it can save a life.

For cyclists, there’s Bluetooth heart rate broadcasting – the watch can transmit heart rate data to a cycling computer or trainer. Devices like Garmin Edge, Bryton, or Magene are supported, but you need to check if your specific device supports the BLE protocol for heart rate.

Software and User Experience: HyperOS with Limitations

The watch runs on Xiaomi HyperOS and pairs with a phone via the Mi Fitness app. Compatibility is broad – it works with both Android and iOS, but you’ll get the greatest benefit with Xiaomi phones thanks to Xiaomi Interconnectivity. This allows you to control media playback on your phone, find a lost mobile by ringing it, or even remotely trigger the camera.

The interface is intuitive. Rotate the crown to navigate menus, swipe down to open quick settings, swipe up for notifications. Xiaomi has redesigned the vertical interactive frame, which now offers Xiaomi Smart Hub – controlling smart devices directly from the watch. However, this feature requires a phone with HyperOS 2 or 3, so owners of older Xiaomi or other brands do not have it available. Unfortunately, the smart panel was not available on the Galaxy Z Fold7.

An interesting feature is customizable finger-snap gestures. You can use them to reject a call, open the weather, or launch your phone’s camera. It works surprisingly reliably, although occasionally I experienced false detection and a call was automatically rejected. Hopefully, an update will fix this.

The problem arises with third-party applications. The Watch S4 41mm is limited to Xiaomi’s first-party apps – Alarm, Weather, Tasks (via Mi Notes), Calendar. You cannot install Spotify, YouTube Music, or anything else.

Another drawback is the inability to reply to messages directly from the watch. You can see notifications, you can reject a call, but you cannot reply to an SMS or WhatsApp message directly from the watch. Xiaomi Interconnectivity partially addresses this through quick replies, but only on phones with HyperOS.

Safety Features: SOS Button and Location Sharing

As described above, the Watch S4 41mm has a dedicated SOS button – press the bottom button three times and the watch will automatically call an emergency number. In less critical situations, you can share your real-time location with pre-set contacts. The function requires the watch to be constantly connected via Bluetooth to the phone, and the Mi Fitness app must be updated.

On Android, sending SMS messages with the current location also works, but on iOS, this function is unfortunately limited by the system. The watch also has an emergency siren – a loud alarm to deter potential attackers or attract attention from bystanders.

Battery: Eight Days with Reasonable Use

The 320 mAh battery is rated by Xiaomi for 8 days of light use. In practice, I even managed 10 days with AoD turned off.

With normal use, including active high-precision sleep monitoring, all-day stress and SpO2 tracking, intelligent heart rate monitoring, and 180 minutes of GPS exercise per week, expect 4 days. With the always-on display and intensive use, it’s 2-3 days.

What about payments?

The Watch S4 41mm has an NFC chip, but in the Czech Republic, payments can only be made with cards from ČSOB or mBank. If you have a different card, you will need to download the Curve app, register, and use their services. While it’s annoying, you are still able to enable payments (unlike, for example, Huawei).

Price and Availability: From 3,399 to 3,999 CZK

The Xiaomi Watch S4 41mm is available on the Czech market in four variants. The black and mint green with a fluoroelastomer strap start at 3,399 CZK. The variant with a white leather strap costs 3,799 CZK. The most expensive is the Sunset Gold with a diamond and Milanese strap for 3,999 CZK.

Verdict: Elegant Watch with Brains, but Limited Software

The Xiaomi Watch S4 41mm is the most elegant watch Xiaomi has ever produced. Compact dimensions, premium materials, an improved display, and solid hardware make it an attractive choice for people who want an elegant piece of jewelry with smart features.

Health features are excellent – continuous skin temperature measurement, improved sleep monitoring with practical advice, accurate heart rate tracking even while swimming. Female cycle prediction based on temperature changes is a feature that will be especially appreciated by women looking for more accurate data than classic calendar apps offer.

Sports features cover all basic and advanced needs – 150+ modes, dual GNSS, Bluetooth heart rate broadcasting for cyclists, fall detection for skiing.

But then there are the software limitations. The inability to install third-party applications, the inability to reply to messages directly from the watch – these are shortcomings that will frustrate you in daily use. If you are used to the freedom of Wear OS watches, Xiaomi HyperOS will feel limited.

Who are the Watch S4 41mm ideal for? For people with narrower wrists who want an elegant watch with good health and fitness tracking features but don’t need advanced functions. If notifications, heart rate, GPS tracking are enough for you, and you want it wrapped in a premium design, you’ll be hard-pressed to find a better option for 3,399 CZK.

However, if you expect a full-featured watch with broad app support and the ability to pay with a card from the watch, you will be disappointed. And unfortunately, for that price, you can already get competitors with Wear OS, which offers significantly more in terms of software.

Editor’s rating: 82%

How do you like the Xiaomi Watch S4 41mm?

We thank Xiaomi for providing the watch.