Introduction and unboxing
This is Xiaomi’s Watch S4 and it’s among the most customizable smartwatches you can get now. It comes in a single 47mm version and in three case colors – silver, grey, and black, but its case bezel can be changed on the fly, giving you practically endless options.
We have the Rainbow model, which is a shade lighter than the Black one. It comes with a unique black bezel with colorful accents and a fluororubber strap with multi-colored stitching. The watch is €170 at the time of this article.
Inside the retail box is the watch, its strap, and a 2-pin magnetic charger. The charger uses USB-A plug, which is disappointing in 2025. It’s also slightly fiddly to attach the charger properly – rival watches like Samsung’s Galaxy Watch and Huawei’s Watch also use a proprietary charger, but it’s magnetic – just plop the watch on top and forget about it.
What’s inside the box
We also have the additional Dual-tone Ceramic bezel and strap kit, which completely overhauls the watch’s appearance. The watch is smarter about swapping bezels, too – there’s now a warning when you remove the bezel – the watch vibrates constantly until you place the bezel back on the watch. A welcome change, considering how easy it was to accidentally pop the bezel off on the Watch S3 and lose it.
The case has a bayonet-style mechanism, where the bezel locks into place.
The additional camera bezel and leather strap
Design and build quality
Even better, Xiaomi went with a standard 22mm band size, opening a world of possibilities for both third-party and Xiaomi straps. Who doesn’t love variety?
There are hundreds, if not thousands, of 22mm lug watch straps on Amazon, AliExpress, and the like, in genuine leather, fake leather, rubber, ballistic nylon and more. But there are also third-party bezels for the Watch S4 already, so you can customize it to your heart’s content!
The Xiaomi Watch S4 has a classic look. The bezel sits prominently on the round case and protrudes a few mm above the screen glass cover, protecting it from scratches.
The case is made of an aluminum alloy, while Xiaomi doesn’t specify anything about the glass, but we’d guess it has some level of scratch resistance.
While some watches use a more hardy and premium stainless steel for the exterior, the aluminum used in the Xiaomi Watch S4 allows for a lightweight package of just 44.5g. In comparison, the OnePlus Watch 3 is 49.7g, while the Galaxy Watch6 Classic is 59g.
The screen is a huge improvement over its predecessor. It’s a 1.43-inch 466x466px 60Hz unit that’s brought the old 600 nits up to 2,200 nits. It’s a noticeable bump – this panel will leave you wanting for nothing, even in the brightest of conditions.
There’s an always-on screen mode that’s tailored to each individual watch face.
There are two controls on the right side of the Xiaomi Watch S4 – one is the new rotating crown, which doubles as a pusher, and below it is another button that sits more flush with the case.
The rotating crown adds a welcome layer of control to the smartwatch. It’s precise, and has a lovely vibration feedback.
The controls
The heart rate and blood oxygen combo sensor sits on the bottom of the watch (it lights up in green and red). This is also where the two pins for the magnetic charger sit.
The 1.43-inch 466x466px AMOLED display is, again, superb – crisp and bright. But it’s Xiaomi’s effort in making sophisticated watch faces that makes it even better. There are nine built-in faces, all high quality, all featuring a myriad of customizable widgets for different data – battery life, steps, the day of the week, etc.
Our only slight gripe is that all the watch faces are black – great for AMOLED battery endurance, sure – but we’d like a few lighter faces too. You can find a lot of additional watch faces in the Mi Fitness app, so it’s all good.
The Xiaomi Watch S4 is kind of unique in that it’s a large watch at 47mm, but also light. It’s for the unique user who likes them big but light! The Watch S4 lends itself perfectly to the duty of a fitness or sleep tracker.
On the other hand, people who like a little heft to their watch won’t be the biggest fans of this one.
Xiaomi equipped the Watch S4 with its HyperOS 2, with seamless device connection with Xiaomi’s Smart Hub. A push on the crown tak
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