Xiaomi Watch S4

The Xiaomi Watch S4 in its 41mm version is a round stainless-steel smartwatch aimed at people who want a slimmer, more classic-looking watch than the typical sports model. It combines a 1.32-inch AMOLED screen, built-in dual-frequency satellite positioning, a skin temperature sensor and a battery that Xiaomi rates at up to eight days under light use. This page is based on the published specifications and manufacturer information. It covers where the watch fits among Xiaomi's wearables, what the hardware offers, and the limits a buyer should know about.

Place in the lineup

Xiaomi's global product page lists this model as the Xiaomi Watch S4 41mm, which signals that the "S" series is the brand's more elegant, jewellery-leaning line rather than its rugged sports line. In the wearable range it sits above Xiaomi's inexpensive fitness bands such as the Xiaomi Smart Band 10, offering a full round watch face, a stainless-steel frame and a more complete sensor set. The release date used on this page is 2 March 2025, used because the manufacturer pages consulted here do not state an on-sale date, and availability of the 41mm model and the Sunset gold edition differs by region.

Four colours are listed: Black, White, Sunset gold and Mint green. They come with different straps. The black and mint green versions use a fluororubber strap, the white version a leather strap, and the Sunset gold edition a Milanese mesh strap and, according to Xiaomi, a lab-grown diamond set in the crown. Xiaomi says the Sunset gold edition may not be sold everywhere.

Design and display

The case is 41.2 x 41.2 x 9.5 mm and the watch weighs about 32g without a strap. The frame is stainless steel. Xiaomi says that thickness excludes protrusions and that weight excludes the strap supplied in the box. For many wrists, especially smaller ones, a 41mm case is the main attraction: it is noticeably more compact than the 45mm to 47mm cases common on sports watches. Straps are adjustable, with roughly 120 to 190mm for the fluororubber, leather and white versions and 130 to 190mm for the Milanese strap.

The display is a 1.32-inch AMOLED panel with 466 x 466 pixels, which works out to 352 ppi. Xiaomi quotes a high-brightness-mode figure of 1,500 nits, and notes that this is the maximum when the entire screen lights up. The refresh rate is 60Hz and may vary between interfaces. Xiaomi advertises more than 200 watch faces, including animated pet faces tied to a "Pet Park" feature in which daily calories burned are exchanged for food for a virtual animal. Whether that appeals is a matter of taste, but it shows the watch is aimed at a style-conscious and casual-fitness audience.

Water resistance is rated at 5ATM. Xiaomi explains that this means it can be worn in swimming pools and for shallow water activities near the shore, but it is not suitable for hot showers, saunas or diving.

Health and sports features

The sensor set includes a heart rate sensor with blood oxygen measurement, an accelerometer, gyroscope, ambient light sensor, compass, barometer and a skin temperature sensor. Xiaomi says the temperature sensing can detect changes as small as 0.1 degrees Celsius. It can be used for single measurements to spot a raised skin temperature, such as with a fever, or for all-day monitoring with a configurable alert threshold. The same data also feeds female cycle predictions, which Xiaomi says combine vital signs with menstrual history to estimate period start, ovulation and fertile windows.

Sleep tracking is another focus. Xiaomi says it worked with international sleep organisations on the recommendations, and the watch offers a sleep score, a bedtime routine view, ideal sleep duration and a multi-day sleep improvement plan. A one-tap Checkup app gives a quick overview of heart rate, blood oxygen, sleep and stress. All-day blood oxygen and stress monitoring are available, along with breathing exercises. As with all consumer wearables, these readings are meant for general wellness awareness; they are not a substitute for professional medical advice.

For sports, the watch offers more than 150 modes, a post-workout report with a heart rate curve, aerobic and anaerobic training effects, load and recovery time, and live heart rate display in swimming mode. Heart rate can be broadcast over Bluetooth to bike computers. A professional skiing mode adds fall detection; if you do not respond within 60 seconds, the system calls your emergency contact. Positioning uses built-in L1+L5 dual-frequency GNSS covering GPS, Galileo, GLONASS, BeiDou and QZSS, which should help with accuracy in built-up areas compared with single-band watches. The watch is compatible with Health Connect and some third-party apps such as Suunto, according to Xiaomi.

Safety features

Xiaomi puts weight on personal safety. Pressing the lower button three times starts an emergency SOS call to your chosen contact. An emergency siren can be triggered from the screen, and a live location-sharing request can be sent to your emergency contact list. These features are useful for people who walk or run alone, though they depend on a connected phone and on the contact being reachable.

Software, battery and connectivity

The watch runs Xiaomi HyperOS 3 and pairs with Android 8.0 and later or iOS 14.0 and later through the Mi Fitness app. Bluetooth 5.4 handles the connection. Bluetooth calling is supported through the paired phone (not third-party app voice calls, which Xiaomi says are not supported), and NFC is included, although availability varies by region. There is one microphone and a speaker. Charging uses a two-pin magnetic dock.

The battery capacity is 320 mAh. Xiaomi's figures are up to 8 days for light usage, up to 4 days for normal usage and up to 3 days for heavy usage. Those are manufacturer numbers, and features such as always-on display, continuous monitoring and frequent GPS workouts will push real life toward the lower end. Even so, several days between charges is a clear advantage over full-featured watches that need charging every day or two.

Who it is for

The Watch S4 41mm suits people who want a smaller, more elegant round watch with solid health tracking and decent endurance, and who are comfortable using Xiaomi's Mi Fitness app. It will appeal to those who find 45mm-plus sports watches too bulky. Someone choosing between this and a mainstream smartwatch such as the Galaxy Watch8 should consider the ecosystem: Xiaomi's watch works with both Android and iOS phones, but it does not offer the kind of deep phone integration that a platform-specific watch provides. The page Xiaomi Watch S4 vs Galaxy Watch8 lines up the numbers, and the rankings give a wider view.

Compromises

The display refresh rate is 60Hz and the screen is small, so dense information can be harder to read than on larger watches. A single microphone and the exclusion of third-party voice calls limit the call features. NFC availability depends on the country. The 5ATM rating makes it suitable for swimming but not for diving or hot showers. The Sunset gold edition may not be available in every market. Finally, Xiaomi's pages do not state a price or an official on-sale date for the watch, so confirm both with your local seller. For its size and set of features, it is a well-rounded option for style-focused wearers, with the usual caveat that battery claims and health readings are manufacturer figures rather than independent measurements.