The Xiaomi Watch S4 smartwatch offers a comprehensive suite of features within a stylish and classically-inspired design. Departing from the prevalent square and boxy aesthetics of current smartwatches, this model embraces a traditional form factor while incorporating advanced smart capabilities. The result is a versatile smartwatch suitable for diverse styles, further enhanced by the user-replaceable strap system. During testing, the included gray strap was easily exchanged for a black variant. This proved to be a surprisingly straightforward process, requiring only a simple slide of the fingertip against the release button located on the underside of each end.

Useful Additional Features
The 1.43-inch screen size provides an optimal viewing experience. It strikes a balance between being sufficiently large for easy navigation and avoiding excessive bulk. The dimensions feel well-suited for navigating the interface via touch. Navigation is also possible using the rotating crown, which functions as a scroll wheel. Adjacent to this is a rectangular button, which when pressed, grants access to additional smart functions, including:
• A flashlight function, which utilizes the screen. While functional, increased brightness would be beneficial.
• A phone-finding feature that triggers a ring on the connected smartphone – particularly useful for locating misplaced devices.
• A function designed to expel moisture from within the watch.

Beyond Basic Activity Tracking
The Xiaomi Watch S4 emphasizes health and fitness tracking. It monitors metrics such as steps taken, heart rate, blood oxygen saturation (SpO2), sleep patterns, and stress levels. During a brisk walk, the watch delivered a notification stating: “7,000 steps completed – great job!” A double-tap on the watch face displays summarized statistics on movement, steps, and calorie expenditure. The Mi Fitness app, compatible with the watch, provides more comprehensive data analysis. This app was tested with an iPhone 13 Pro. Functionality may potentially expand when paired with a Xiaomi phone.
The watch automatically enters a low-power mode when inactive. A wrist-shake gesture reactivates the screen, although the responsiveness of this feature can be affected by the tightness of the watch band. A looser fit may result in inconsistent activation. This can be mitigated by tightening the band or by manually pressing the crown. For optimal data collection regarding heart rate and other biometrics, a snug fit is generally recommended.

Impressive Battery Performance: Up to 15 Days
For users with active lifestyles, a quick 5-minute charge can provide up to two days of usage. Currently, after six days since the last full charge, the battery level remains at 72%.
Standard features include push notifications for apps and SMS messages. The watch also supports answering phone calls.

Final Verdict
In conclusion, the Xiaomi Watch S4 is a stylish and feature-rich smartwatch with a strong emphasis on health tracking. While generally impressive, improvements could be made to the flashlight’s intensity and the reliability of gesture-based screen activation with a looser fit. Nevertheless, the Xiaomi Watch S4 represents a compelling offering in the smartwatch market.
Xiaomi provided a review unit for this evaluation. The provision of review materials does not influence our editorial independence. Our reviews are conducted independently, with a focus on providing accurate information to our readership.