Xiaomi Watch S4 review: a budget smartwatch that feels high-end but has its limits

The Xiaomi Watch S4 is the Chinese brand’s latest attempt to deliver a premium experience at a more accessible price, and it has been pretty successful this time around.

At first glance, the Watch S4 looks and feels like a high-end smartwatch, boasting a 1.43-inch AMOLED display with excellent brightness, a rotating crown for easy navigation, and a lightweight yet durable frame.

Xiaomi has also put an emphasis on customisation, offering a range of straps, bezels, and over 200 watch faces to suit different styles. (My preference was the orange strap.) Like the Garmin Venu 3, it bridges the gap between fitness-focused wearables and everyday watches, but at a significantly lower cost.

Of course, competition to be the very best is tough, and customers are likely to be looking at the Apple Watch SE 2 and smartwatches from Samsung, Huawei, Garmin, and others before buying the S4. Let's see what the Xiaomi Watch S4 can do.

Xiaomi Watch S4 review

Price and availability

The Xiaomi Watch S4 is available in the UK for £129.99 (approx. $166.94/ AU$265.69) directly from Xiaomi, making it an affordable option compared to rivals like the Samsung Galaxy Watch 6 or the Huawei Watch GT 4.

For those outside of the UK, Europe, and China, getting the Watch S4 might prove trickier as Xiaomi does not seem to sell its devices in the US or Australia.

While some third-party retailers may stock it in those regions, availability is limited, and there is no direct pricing from Xiaomi’s US or Australian websites.

Specifications

Xiaomi only sells one version of the Watch S4 and so the specs are fairly easy to grab. Go to Xiaomi's website to see the full specifications.

• Bezel: Interchangeable, aluminum alloy frame
• Display: 1.43” AMOLED, 466 x 466 pixels, 1,500 nits HBM brightness
• Lens: High-gloss PVD finish
• Weight: 44.5g (without the strap)
• Water resistance: 5ATM
• Battery: 486 mAh and up to 15 days battery life
• Charging: 2-pin magnetic charging (with fast charging)
• GNSS: Dual-frequency positioning for outdoor tracking

Design and build quality

From the moment I first used the Xiaomi Watch S4, it was clear this is a smartwatch that punches well above its price point. The sleek aluminium alloy frame has a premium feel, with a high-gloss PVD finish that mimics the look of stainless steel.

One of the standout features of the Xiaomi Watch S4 is its interchangeable bezel system, which adds an extra layer of customisation. Unlike most smartwatches where you’re stuck with a single frame design, Xiaomi lets you swap out bezels to match your style.

It’s a clever touch that makes the watch feel more versatile, though additional bezels will set you back extra cash on top of the £130 for the S4.

The 1.43-inch AMOLED display is another highlight. With a 466 x 466 resolution and peak brightness of 1,500 nits, it’s crisp, vibrant, and easy to read even in bright sunlight, useful for use in the summer.

Colours pop, text is sharp, and the 60Hz refresh rate makes animations feel smooth. It’s not quite Apple Watch Ultra levels of polish, but for this price, it’s seriously impressive.

Xiaomi has also nailed the physical controls. The rotating crown is satisfyingly tactile and makes scrolling through menus much easier than relying solely on swipes and taps, which was the case in prior versions.

There’s also a secondary button, which can be customised for quick access to frequently used features and workouts, a simple but effective setup that makes navigation intuitive.

The strap options are another plus. Out of the box, you get a fluororubber strap, which is soft, comfortable, and resistant to sweat – ideal for workouts. But Xiaomi offers other materials, including leather and nylon, if you want something more refined. I personally liked the orange strap option.

The quick-release mechanism makes swapping straps effortless, adding to the overall flexibility of the design, and meaning the S4 could change with my outfits (which, to be fair, was mostly black gym wear).

Durability-wise, the Watch S4 holds up well. It’s rated for 5 ATM water resistance, meaning it can handle swimming, rain, and general splashes, though it’s not built for deep diving, so factor that in.

Overall, the aluminium frame feels sturdy, and while the screen doesn’t have sapphire protection, it’s resistant enough to shrug off minor knocks and scratches from daily wear. I bumped it a few times on gym equipment and it's remained scratch-free.

One minor gripe is the lack of a rotating bezel, which would have made navigation even smoother. Some users might also prefer a slimmer profile, as the watch does sit slightly chunky on the wrist compared to something like the Garmin Venu 3 or a Fitbit. But unless you have particularly small wrists, it’s unlikely to be a dealbreaker.

Features and accuracy

The Xiaomi Watch S4 packs an impressive suite of health and fitness tracking features, covering everything from heart rate and blood oxygen monitoring to stress tracking and sleep analysis.

The company has even included a one-tap health insights tool, which gives you a snapshot of key health metrics in 60 seconds. For a smartwatch at this price, it’s a surprisingly comprehensive set of features.

For general daily tracking, the heart rate and SpO2 monitoring were consistently reliable. I compared the readings to those from a dedicated chest strap and an Apple Watch, and the results were within a very small margin of difference.

Resting heart rate data felt accurate, and during workouts, the watch responded quickly to changes in intensity. Stress tracking and sleep analysis were also useful, with the latter breaking down sleep cycles into light, deep, and REM stages.

One of the biggest selling points of the Watch S4 is its dual-frequency GNSS, which helps improve location accuracy for outdoor workouts. In my tests, GPS tracking for running and cycling was generally spot-on, even in built-up areas where cheaper smartwatches can struggle. The signal acquisition was fast, and route mapping was detailed, making it a solid choice for outdoor training.

For indoor workouts, things were a little different.

Treadmill running required manual calibration to get accurate distance readings. Initially, the watch was underestimating distances compared to the treadmill’s display, but after a couple of adjustments, the accuracy improved significantly.

It's worth noting that this is fairly common with smartwatches, and Xiaomi does allow you to fine-tune distance tracking, which is a plus.

The 150+ sports modes offer more variety than most people will ever need, including myself. It covers everything from running, swimming, and cycling to more niche activities like rock climbing and rowing.

The watch automatically detects some exercises, like walking and running, but I found the auto-detection a little hit-and-miss, and it sometimes took a minute or two to register that I was actually moving, making everything out of sync.

Beyond fitness, the smart features are decent, though not as advanced as something like the Samsung Galaxy Watch 6. Notifications come through reliably, and you can answer or reject calls, but there’s no support for third-party apps like Spotify or WhatsApp.

The watch does integrate well with Xiaomi’s HyperOS ecosystem, letting you control smart home devices and sync data with Suunto for more advanced training analysis, although these products are pretty niche in the UK.

Performance

I found the Xiaomi Watch S4's day-to-day performance to be smooth and responsive, thanks to Xiaomi’s HyperOS. Swiping through menus, launching apps, and using the rotating crown all feel fluid, with no noticeable lag.

The 60Hz AMOLED display helps make animations look slick, and transitions between screens are seamless. While it’s not as snappy as something like an Apple Watch, it never felt slow or frustrating to use.

One bugbear I have is when a smartwatch is hard to use when running, especially later on when you're fatigued and just want things to happen quickly. The S4 always kept up with my frantic taps on the screen to check my heart rate and other data after 30+ minutes of running.

The rotating crown adds a welcome physical control, especially when scrolling through long menus or checking detailed health stats. This is something you don’t always find on budget smartwatches, and it makes a big difference in day-to-day usability.

In terms of connectivity and integrations, the Watch S4 performs well within Xiaomi’s ecosystem. Bluetooth 5.3 ensures a stable connection to your phone (either Android or iPhone), and notifications come through reliably.

Music controls worked smoothly, but without third-party app support, you’re limited to basic playback adjustments, which is probably one of the biggest drawbacks of the S4.

During workouts, the watch tracked heart rate, movement, and GPS data accurately, though auto-detection of exercises could be more responsive. GPS tracking was generally excellent outdoors, with little signal drop-off.

Battery life and charging

Battery life is one of the Xiaomi Watch S4’s strongest features, with up to 15 days on a single charge in typical use, far better than most premium smartwatches, like the Samsung Galaxy Watch 6 or Google Pixel Watch 2, which often struggle to last beyond two days.

Even with always-on display enabled, frequent notifications, always-on VO2 tracking, and multiple tracked workouts, I comfortably got over a week before needing to recharge.

When the battery does run low, charging is quick and convenient. The watch uses a 2-pin magnetic charger, which snaps into place easily.

A five-minute top-up provides around two days of use, making it easy to keep the watch running if you forget to charge it overnight. A full charge takes just over an hour, which is fairly standard for a smartwatch of this size.

Unlike some competitors, there’s no wireless charging, which would have been a nice addition. However, given the strong battery life and fast charging, it’s not a major issue, for me anyway.

Verdict

The Xiaomi Watch S4 is a budget-friendly smartwatch that doesn’t feel budget.

With its premium aluminium design, bright AMOLED display, and customisable bezels, it looks far more expensive than it is. The rotating crown and intuitive controls make it easy to use, while its comprehensive fitness tracking and health features hold up well against pricier alternatives.

In terms of performance, battery life, and usability, it’s one of the best smartwatches at this price. The only real downside is that some features, like treadmill tracking, need calibration for the best results.

HyperOS runs smoothly, notifications work reliably, and GPS tracking is strong, while the 15-day battery life is a major highlight, outlasting many rivals.

Smart features are slightly limited due to the lack of third-party apps and contactless payments. If you want deeper app integration, the Samsung Galaxy Watch 6 might be a better choice.

That said, if you want accurate health tracking, long battery life, and a stylish design, the Watch S4 is a fantastic choice for the money.

Also consider

If you’re looking for alternatives to the Xiaomi Watch S4, there are a few strong contenders depending on your priorities.

The Amazfit Active 2 is a great budget-friendly option, coming in at under £100 and featuring a bright AMOLED display, AI voice controls, and decent fitness tracking, along with offline maps for outdoor workouts.

For those wanting something more established, the Samsung Galaxy Watch 4 is a compelling alternative, and has previously been available for as little as £130, making it a direct price competitor to the Xiaomi Watch S4. With Samsung’s refined Wear OS software, strong health tracking, and seamless integration with Android devices, it’s a great option.

Another alternative worth considering is the Huawei Watch GT 4, which sits at a slightly higher price point but offers a refined design, excellent battery life, and more advanced fitness tracking.