Limited but expressive

Review: Xiaomi Watch S4 41 mm - appearance above all

A small and sleek watch with a focus on appearance, but also training and health.

Published 9 December 2025 - 16:36

This is a smartwatch that can have several different expressions. The Watch S4 was released earlier this year, but this is a new more compact model. I test several of the different models of the S4 41 mm, all with different appearances and made of different materials. The reason for this is that I first get to choose which model I want to test and I opt for the gold one, as it has an appearance that stands out among smartwatches. It simply looks more like a traditional and also neat little watch.

Slides around and falls off

The strap is in gold metal and the fastening is a magnetic connection that is supposed to keep the watch in place. By moving one part of the fastening, I can adjust how large the strap should be. The problem is that it doesn't work. No matter what I do, the strap becomes both too loose and has poor locking ability. It slides up and down the arm when I walk and when I sleep, and several times, when I make even the slightest jerky movement, like running for example, the whole watch with its strap falls off the arm onto the ground.

I have experienced this before, in the sense that I know how different an experience I can have with a watch depending on which strap comes with it. I think it's wrong to completely judge the watch itself based on just the strap, so I ask for another example of the watch, this time one with a rubber strap and proper fastening. The experience becomes largely completely different.

Doesn't have many advanced features, but has battery life

Basically, the Xiaomi Watch S4 41 mm is a simple watch. It has Xiaomi's own operating system, which means you can't download apps, don't have e-sim, can't respond to notifications from the phone from the watch, but you do have training, health, and sleep tracking, you have contactless payment in stores, and you have good battery life of around a week.

When I use the watch, both the model with the gold strap and the one with the rubber strap, as the functions and features are identical, a night's sleep tracking takes about 6-7 percent. After two days of use with both sleep tracking and a longer training session per day with gps, the watch's battery has gone from 100 to 64 percent. A total battery life of just under a week, then.

Accurate but limited

The training measurement, both distance and gps position, seems to be accurate when I compare it with other measurement methods. All data is collected in the Mi Fitness app and there, as well as directly in the watch, I can follow the data that has been collected. I get information about my sleep, my general health, and details about the training session. I am supposed to fill half circles with calorie goals, steps, and movement every day. I can follow all this as well as calculated Vo2Max, running ability, and training load, but I miss analysis and guidance. Now it just becomes a long list of values that are difficult to put into context without help.

From the app on the mobile, I can choose to share workouts to Strava, Health Connect on Android or Apple Health on iPhone, as well as Suunto. When I choose to automatically send all my workouts to Strava, they are regularly uploaded without a GPS route, which almost negates the entire benefit. In other areas too, the Xiaomi Watch S4 41 mm is limited. As I mentioned, I cannot reply to notifications directly on the watch. Connected to an Android, I can load music files into the watch and play independently of the phone, but this is not possible with an iPhone. Somewhat surprisingly, Xiaomi has its own electronic wallet so you can tap payments with the watch in-store, but the selection of banks is limited, only Swedbank, SEB, and Curve.

One thing at a time

Unfortunately, multitasking is limited, or rather almost non-existent in the watch. If a workout is in progress, I cannot do anything else on the watch, such as record a voice memo, check the calendar, or even read any incoming notifications without first ending the workout. At least I can see the time as the time indication is also available in the workout view.

It may not be such a big problem, as the watch does not have many functions. The interface is simple. A press on the round button brings up the icons for temporary functions, and if I swipe up from the watch face, I get today's training status, heart rate trend, weather, and then apps. Some watch faces can display selected information directly so you always have easy access to steps, blood oxygen level, sleep, and so on directly on the watch face.

The watch is limited in function and this means the battery life is good. I get about a week of battery life. The functions that are available work well, but I think both the analysis of your training is missing and that some functions are lacking, so the watch has clear priorities.

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