- Large and vibrant display
- Solid battery life
- Cheaper than other flagships
- Average accuracy in all key areas
- Lacking proper smartwatch features
- Design doesn't feel that 'Pro'
The Xiaomi S1 Pro represents the company's first real attempt at a more premium smartwatch.
After arriving late to the party - only launching its first smartwatch outside of China in 2020 - we've now seen several efforts from Xiaomi, but none have commanded the same price as the S1 Pro.
And despite bossing the world of budget fitness trackers for nearly a decade, the company has yet to really find the same traction with its smartwatches.
Not much has changed when it comes to the Pro edition, unfortunately, though there are a couple of bright spots for those desperate to strap a Xiaomi smartwatch to their wrist. Here's our full take.
Design and display
Xiaomi has bumped up the display for the Pro edition, and the 1.47-inch AMOLED display feels much more prominent than on the standard S1 due to the reduced bezel size.
The case size is still 46mm, though a fancy new digital crown has been added in place of one of the S1's pushers. And despite sticking out a fair bit, this actually works really nicely, making for a really intuitive way of navigating menus and on-watch stats.
The lug design is also improved, we think, now featuring a small gap between the bezel and feeling less chunky than the standard S1.
While there are definite improvements over the cheaper sibling, though, we're not totally convinced about the actual look.
The display is crisp and the UI is very smooth, but the case's look also feels pretty outdated - in fact, it really reminds us of some of Fossil's old smartwatches, like the Q Explorist.
With Samsung, Apple, Google and other major smartwatch players cementing their unique case designs, the S1 Pro instead feels very generic.
We expect some will like the pretty barebones styling. But, even then, we also don't think it achieves the kind of premium, classic timepiece feel that Xiaomi has tried to install.
The leather band feels relatively cheap, while the stainless steel case and overall size are odd fits for a watch that still leans much more toward fitness tracking than pure smartwatch features.
The S1 Pro is, at least, fairly durable. Xiaomi has installed sapphire glass over the top of the AMOLED display, and it has remained very scratch-resistant.
We typically find screens or cases with scratches on from our opposing hand's ring, or dings from the gym, but it's held up very well.
We also feel pretty good about recommending it for the water - even if, as we say, the design isn't super practical for workouts.
We haven't tested it out in a swimming pool setting, but, even with a leather strap, it felt fairly resilient after showers, and there's been no screen fogging or anything alarming.
Xiaomi has slapped a 5ATM water rating on the S1 Pro - that should mean it's able to withstand water pressures equivalent to 50m.
If you were expecting Xiaomi to take a leap forward in this area with the S1 Pro, get ready to be disappointed. Despite being styled as a smartwatch, the Pro still just basically offers the bare minimum.
Alexa support is limited to screen read-outs, despite the presence of a speaker, and there are no third-party apps for you to flesh the library of stock options out with. Xiaomi Pay also proved relatively buggy, and is something we gave up on after not being able to get past the initial setup screen.
With no cellular option, either, it means the S1 Pro doesn't really have much more to offer than your typical fitness tracker.
Notification support may appear relatively rich on screen and can support texts and calls once you've enabled them in the Mi Fitness app, but the third-party notification support is actually limited to a crop of mostly China-only apps, which is a real shame.
The new MUIU Watch OS software is responsive and easy to make your way around, at least, even if it's not actually hugely different from what came before.
This is also backed up by a decent array of watch faces for you to cycle through and customize within the Mi Fitness app. Whether you prefer digital or analog faces, you're well catered for here - and it does at least make the S1 Pro feel a bit more of a smartwatch.
Workout tracking accuracy
While we're not entirely surprised to see the S1 Pro continue to forego some smartwatch features, the specs sheet does suggest that it'd be able to offer a pretty solid tracking experience.
From our tests, though, the accuracy of the eye-catching dual-frequency GPS and heart rate monitor falls short of the top options around. There are some neat insights for runners, such as cadence estimations and stride details, but, largely, this is a workout tracking experience that's available on most other fitness trackers.
Heart rate tracking comparison
We'll preface this by saying that the S1 Pro actually performed reasonably in a good portion of the 10 workouts we logged with it. Steady-paced runs and strength sessions were typically always within a few beats of our Garmin Forerunner 265 when we were checking in real-time, and the post-workout averages lined up nicely with Whoop, as well, as shown below.
However, it did also have a couple of unmitigated disasters.
On one outdoor recovery run shown below, the S1 Pro appeared to register our heart rate climbing during a hill section, but then got stuck around this heart rate reading for the remainder of the exercise.
This resulted in the average BPM for the session being 170BPM, rather than the 146BPM average that Garmin and Whoop both logged.
We had a similar experience in a strength training session.
After our heart rate dropped significantly mid-session, it then failed to get back up to speed, logging the rest of our workout in the sub-100 BPM range and well below the averages of our other devices.
Instinctively, this feels like a software glitch that Xiaomi could resolve with a future software update, but, for now, just be aware that the heart rate monitoring during workouts is prone to the odd hiccup.
Dual-frequency GPS accuracy
After initially only being available on premium sports watches, dual-frequency GPS is now beginning to trickle down to mid-range devices like the S1 Pro.
However, despite the watch being able to communicate via GPS, GLONASS, Galileo, BDS and QZSS satellite systems, the implementation here isn't completely solid.
The location lock-on was swift - and things are helpfully marked with a signal icon throughout outdoor workouts - but it also seemed to underreport distances by quite a significant margin on a couple of occasions.
While two runs we tracked were both right in line with our Garmin and had us encouraged, another two were close to being half a mile behind.
When you go back and look at the tracking worm, as well, the level of detail just isn't really in the same ballpark.
Take the example above. While the Forerunner 265 is able to zero in on exactly where we were running on the pavement, the S1 Pro instead has us placed on the nearby field.
And we'd actually say this is one of the more generous examples we could have used, with the majority of lines drawn by the tracking worm actually even further from where our trail actually took place.
It was a very similar story when we tested the Watch S1 last year, so, all in all, it's pretty disappointing that Xiaomi hasn't found a way to improve consistency since then.
Health tracking features and accuracy
The S1 was a device packed with health features, and Xiaomi has ramped things up for the Pro version by adding a skin temperature sensor.
As a package, it means the Pro is able to take SpO2 readings, track your sleep, provide stress alerts, and deliver on-the-spot temperature measurements.
Kind of strangely, most of these are turned off by default, meaning you'll have to head to the device's settings in the Mi Fitness app just to receive basics such as sleep stages.
Once you've navigated that hurdle, though, our tests showed that things like blood oxygen readings and calorie burn estimations were largely in line with what you would expect from the likes of Whoop and Oura.
Resting heart rate readings sat well above our usual baseline, though it appears Xiaomi takes this from a random point in the day when it deems you as non-active, as opposed to taking this from your heart's lowest BPM or average BPM during sleep.
Despite some decent accuracy here, though, we would note that none of it feels that consequential.
Unlike the best health watches, there's no knock-on effect to tracking any of this data. With no daily recommendations or trends that are highlighted to you, it means something like a bad night's sleep sits in isolation from the rest of your health insights, and you're left to piece it all together yourself.
A lot of the data is also pretty hard to engage with in the Mi Fitness app, suffering from the same inaccessible feel as Apple Health, which, pretty predictably, it seems to take some inspiration from.
An example of this is presented with something like skin temperature data. While readings are logged neatly, there's nothing really for you to take away - and it also relies on you manually taking readings to populate it, as with other areas of the app.
With the likes of heart rate variability and ECG readings also scarce, it all just feels a bit half-baked from Xiaomi.
Sleep tracking accuracy
This general theme is pretty summed up in the S1 Pro's sleep tracking. We've been logging our nighttime rest against Oura and Garmin, finding that the general picture is mostly accurate but lacks any of the real detail of these other platforms.
For example, end figures on restorative and light sleep are usually within the same ballpark, as shown above, but the sleep stages are much less detailed. You'll wake up to long periods of certain sleep stages being registered, and, oddly, there's no appetite from Xiaomi here to log any awake time.
In a good chunk of our tests, like the one shown below, it also wouldn't differentiate between 'Deep' and 'REM' sleep, simply choosing one or the other.
We don't put too much stock into the accuracy of any wrist-based tracker's sleep stages, but it is also true that the experience here doesn't feel quite as thought out as what we see from others.
For those wanting the pure basics, such as total time in bed, it will certainly be enough, but this level of insight is also available in trackers available for a fraction of the price.
Battery life and charging
For all of the S1 Pro's sore spots, the battery life is one area that's pretty difficult to argue with.
Xiaomi is promising 14 days here, and, in use, it does feel like a jump from the standard S1.
With that said, you'll need to be strategic if you do want to get the most out of the 500mAh unit. As we've already mentioned, some tracking features are turned off by default, and turning them on takes a few days off that 14-day estimation straight away.
The always-on display is another feature that will hit those battery hopes.
Without any GPS-tracked exercise, we would experience a daily drop-off of around 5-10%, which would equate to around 10-11 days. However, with an hour-long run using dual-frequency tracking shaving off around 10% itself, this is a big factor in how much you can hope to extend it.
Given that we did track outdoor exercise very frequently, we were only able to make the S1 Pro last around 8 days.
Still, since we turned on the always-on display and all the tracking features, we'd rate this as pretty good going - even if we'd also wager this would drop down further if Xiaomi installed some proper smartwatch features.
If you did have any lingering battery concerns, this should be allayed by the S1 Pro's speedy charging. Throwing the S1 Pro onto the charging disc for around 20 minutes will see it gain around 40%, so you're pretty unlikely to suffer here.
How we test