Redmi Watch 4 review – Wareable

With solid entry-level releases from Amazfit, Honor, and Nothing arriving over the last year, the Redmi Watch 4 is the Xiaomi sub-brand’s latest attempt to stay competitive.

To entice those looking to scrape maximum value from the bucket of smartwatches released in 2024, Redmi – as you would expect – is adding a few neat features to this year’s edition. 

It still boasts the same square-cased, Apple Watch-like design as previous generations, though the materials, screen size, and strap mechanism have all been tweaked. 

The insides, too, are getting an upgrade. Redmi promises improved accuracy from the sensor array packed inside the Watch 4, and that extra chunk has also freed up room for a bigger battery unit. 

It’s certainly an improved smartwatch compared to its predecessor, but there are still major caveats to choosing a device at this end of the market. Here’s how we’ve got on with the Redmi Watch 4 during testing.

Price, competition and availability

As we alluded, the budget smartwatch market has popped considerably over the last few years.

New offerings like Xiaomi’s Poco Watch and CMF by Nothing’s Watch Pro (£70) have entered the market while existing manufacturers – Huawei and Amazfit – are churning out more capable watches than ever. 

With the Redmi Watch 4 coming in at £80, it’s actually a bit cheaper than many of the true watch-style devices, which often sit north of £100/$100. The most comparable here are the Amazfit Bip 5 (£90) and Honor Watch 4 (£100), though there are also a ton of fitness tracker-smartwatch hybrids such as the Xiaomi Smart Band 8 Pro (£60) and Huawei Band 9 (£50). 

Price is important, obviously, but it’s much of a muchness here. Most devices in this £50-100 bracket perform very similarly, so the deal-breakers can often be the availability. Those in the UK and Europe can often access these quite easily, but Chinese brands like Xiaomi and Huawei (and, by extension, their sub-brands) don’t have quite the same presence in the US. 

While the Redmi Watch 4 is available via third-party retailers in the US, it can often come at a bit of a premium, so consider that when weighing it against alternatives.

Design and display

One of the headline upgrades Xiaomi has dealt the Redmi Watch 4 is an improved display size; the brand has bumped it to a 1.97-inch here, versus the 1.72-inch screen offered on the predecessor. 

It may not sound like much, but that extra quarter-of-an-inch does make a huge difference – even if the actual AMOLED panel is pumping out the same 450 x 390 pixels and 600 nits of peak brightness. 

If you found the previous screen too cramped, the latest Redmi’s growth should allay your issue. By the same token, though, it is a bit of a shame for those with smaller wrists. 

There’s already an incredible amount of choice on offer for those with larger wrists, and the jump from a 43mm case to a 48mm one – though it has huge benefits in screen readability – surely won’t be to everybody’s taste.

Thankfully, the increase in size hasn’t resulted in the Watch 4 becoming too heavy to wear for things like arm-swinging workouts or sleep tracking. In fact, even though Xiaomi has swapped the Watch 3’s plastic body for an aluminum one here, the Watch 4 is actually lighter.

It clocks the scales at 31.5g, which is remarkable for a watch of this size.

We have less strong feelings about the move to a quick-switch band mechanism. It is slightly easier than using the pin bars to change out a strap on the Watch 3, but it’s hardly revolutionary. 

This and another new design detail – the move to a crown from a single side button – probably adds slightly to the overall feel of the device being more premium than its price tag, but it’s not really a major factor; we still think the Watch 4 and its band feel very cheap on the wrist in comparison to a Wear OS smartwatch, Apple Watch or Garmin watch.

The good news in this regard – if it is good news – is that we don’t think the Watch 4 looks cheap. It simply looks like every other budget watch trying to emulate Apple’s square case design, and we daresay we like the flat-edge display design a bit more than the curved Apple Series and SE devices.

At this price, it’s easy to be forgiving, too. Ultimately, the Watch 4 is a nice-looking device with a healthy display that’s best for those with bigger wrists. It’s not perfect or premium, but you won’t do better for £80.

Smart features and software

Now that we’re a few generations into most budget smartwatch series’, software has generally been refined to a good level. Game-breaking bugs or feature omissions are rare, and that form was followed by the Watch 4 during our testing.

Xiaomi’s HyperOS is a fairly barebones smartwatch software experience, but it does work incredibly smoothly here. The swipe-to-view screens are neat and colorful, and there are lots of unique watch faces with matching always-on display (AOD) versions. 

With apps, there’s no ability to add more from a third-party store like Google Play, but the preloaded drawer does give you access to the basics – syncing for calendars, notifications, and weather, as well as the ability to mirror music playback and calls – alongside dedicated homes for tasks like to-do lists, focus time and smartphone photo-taking control.

You can even link up your Alexa account (above) and access the Amazon smart assistant from the wrist – a neat alternative to the Google Assistant support on Xiaomi’s Wear OS smartwatches. This assumes you’re connected to your smartphone, though, given that there’s no option for cellular support with the Watch 4.

While you can set up the Watch 4 with either an iOS or Android phone, as well, you’re still stuck with the Mi Fitness app as your second home to view all your data. It’s neat enough to navigate, but, ultimately, this does still feel like an app stuck in 2016.

Everything you track can be viewed there – fine – but there’s no consideration given to what your goal is or what data is actually important to you. It’s a hub and not much else – unless you want to tweak settings or sift through the scores of historical data. 

Still, like with some design elements, the shortcomings of Mi Fitness are totally passable for a device at this price. Just don’t have high expectations and you’ll be fine.

Tracking performance

When Xiaomi announced the Redmi Watch 4 would launch with improved, 4-channel sensor technology, we were encouraged. After all, the nitty gritty of heart rate monitoring and sleep tracking is where watches at this price range typically fall to pieces (metaphorically, of course). 

It was a bit of a surprise, then, that the Watch 4 was still plagued by the same kind of inaccuracies as comparable watches and previous versions.

We found heart rate monitoring during cycling, swimming, and strength training to be consistently wide of the mark, with session averages typically around 10 beats-per-minute (BPM) lower than that tracked on Whoop and the Garmin Epix Pro (Gen 2). 

It’s natural for a device a fraction of the price of these gold-standard wearables to fall short, but there was often just too much going on here to glean an accurate enough picture of a workout.

There were a couple of occasions when the sensor dropped to nearly resting heart rate (RHR) levels for minutes at a time, as shown below, and it also struggled to keep up with changes in intensity. 

Sleep tracking, meanwhile, was very good at picking up our falling asleep and wake-up times – always within 5-10 minutes of Oura, Garmin, and Whoop. As usual, Xiaomi also throws in plenty of features to try and color the picture – sleep stages, sleep animals, breathing scores, blood oxygen data, and nightly HR averages.

On the surface, it’s crazy to think you can get this kind of stuff in a budget watch. However, the heart-related figures were, again, totally inaccurate, and the other stuff – like sleep stages and breathing scores – are pretty arbitrary across all wearables, so it’s a bit difficult to give credit.

Rather than our typical RHR of around 45-50 BPM, the Redmi typically tracked our overnight average in the mid-70s. Blood oxygen also saw an average of <95%, which, compared to other trackers and a pulse oximeter, just isn’t the case.

When this kind of shoddy data is combined with Xiaomi’s half-baked attempt at advanced workout metrics, it’s a tracking experience that becomes hard to recommend. 

Unlike most trackers, Xiaomi works these out using your previous sessions – not heart rate. And this ensures something like the training effect tool (above) is still far too sensitive to anything above a recovery intensity, leading to things like recovery time suggestions almost always bordering on the ridiculous, or VO2 max estimates that are miles off. 

It could be argued that these will even out over time into a relatively accurate place, but it doesn’t fill us with confidence when wild data is still front and center after a couple of weeks of very regular exercise. 

It leaves the Watch 4 as a device limited to giving rough ideas of calorie burn, distance (there is a built-in GPS, which a running injury has prevented this reviewer from testing), steps, heart rate, and sleep.

Battery life

With no intensive apps or features to power, battery life is an area in which the Redmi Watch 4 excels. The bigger footprint ensures the battery unit is much bigger than its predecessor; Xiaomi has stuck in a 470mAh pack here, up from the 289mAh present in the Watch 3. 

What does that give us in real terms, then? 

Even after we turned on all the settings Xiaomi likes to turn off by default, such as the AOD, advanced sleep tracking, blood oxygen monitoring, and stress tracking, battery drain was still only around 10-12% per day.

We didn’t harness the GPS for outdoor tracking, which we suspect would see that drop slightly, but the brand’s estimate you could reach 20 days in ‘typical usage’ (which we translate to most modes being turned off) feels about right.

And you can always employ the battery-saving mode shown above, limiting things to steps and time-telling, and get around 30 days if you really need to squeeze things out.