Redmi Watch 4 Review – Tweakers


A large and clear OLED screen, 24/7 tracking of steps, heart rate, stress and sleep, more than 150 sports profiles, a built-in GPS receiver, the ability to take and make telephone calls directly from your wrist, and all the basic functions you need. can expect from a smartwatch: what should it cost?

According to Redmi, in any case not more than 100 euros, because the Redmi Watch 4 has a recommended retail price of 99.95 euros and can even be found cheaper in our Pricewatch. The question of course is whether cheap means expensive in this case, or whether you are indeed in the ring with this watch for a duppie. We looked into it.


Is that an Apple Watch Ultra? I’ve been asked that question more than once lately and although you can see clear differences up close, the Redmi Watch 4 does indeed look a bit similar. This is mainly due to the elongated shape and the aluminum case, the edges of which extend next to the flat screen. We tested the silver-gray version, but there is also a matte black version. The watch uses straps with its own quick-click system that fit nicely on the case. Changing is quick and easy, but you do have to rely on Redmi straps.

The watch has one button to the right of the screen in the form of a digital crown, which has both a rotary and a push function. The crown has a pleasant click feeling and while scrolling through the menus you also get excellent haptic feedback from the built-in vibration motor.

Operation is carried out via the 1.97″ large AMOLED touchscreen. That screen looks very nice, especially for a watch in this price range. With a resolution of 390×450 pixels and a maximum brightness of 600cd/m², the screen is sharp, clear and colorful. The Redmi Watch 4 also has a light sensor on board that ensures that the brightness of the screen is excellently adapted to the ambient light. It is unclear what type of glass Redmi uses. Unfortunately, it does not seem to be the most scratch-resistant variant; during the test period I got an ugly visible scratch on the screen within two weeks.

At the back of the watch we see a central island containing the optical sensors that measure heart rate and blood oxygen levels, and on the side of the crown there are also openings at the bottom for the built-in speaker and microphone.


The Redmi Watch 4 runs Xiaomi HyperOS. Redmi is a sub-brand of Xiaomi, so it makes sense that it uses this Xiaomi-developed software. It is a simple, but smoothly operating operating system that offers basic functions, but cannot be expanded with downloadable (third party) apps. The watch is suitable for working with both Android and iOS devices.

The interface is simple in design. From the watch face you swipe down for notifications, up for the quick menu and sideways for an overview of various widgets. You can organize those widgets yourself and choose which pre-installed functions you want to have quickly available here. Pressing the digital crown opens the overview of all apps/functions.

The watch offers most of the standard smartwatch functions. Of course you can receive notifications and also read them directly on the watch, although not all emojis are displayed correctly. Unfortunately, responding to notifications – from WhatsApp messages, for example – is not possible. If you delete a notification from the watch, it will also disappear from your phone, which is a plus. Of course you can use the watch with the built-in apps to set timers and alarm clocks, you can display task reminders and use the watch as a compass, stopwatch and flashlight.

You can also use it as a remote control for various music and media players on your phone, and as a shutter for the phone camera app. Another nice feature is the ability to use the watch to make hands-free calls: really cool to see this in a watch that costs less than 100 euros. Unfortunately, the speaker volume is set a bit too low by default for my taste, making it difficult to hear the person you are calling. This can be solved by increasing the volume, but you have to do that again with every conversation. It would be nice if the watch would remember the last setting, perhaps something for a future firmware update.

Like almost all smartwatches, the Redmi Watch 4 is also able to measure health functions such as heart rate, sleep and stress. In addition, the watch calculates a vitality score, training load and VO₂ max together with the Mi Fitness app. What is striking is that the data does not always correspond with what my other fitness trackers say. The total sleep time is quite similar to what my Garmin Epix Pro and Google Nest Hub with Soli sensor record, but the data for heart rate, blood oxygen and the number of steps measured all differ significantly from what Garmin and Apple watches record.

By default, the watch measures your heart rate at a ‘smart’ interval during the day, whereby that interval seems to depend on the extent to which you exercise. If desired, you can also set the interval to at least 1 minute, but more detailed measurements are not possible. This results in a heart rate graph that is not a line, but a pattern of dots and strokes with often inexplicable outliers. The same applies to blood oxygen saturation measurements; these also fluctuate enormously. For measuring everyday-health functions, the Redmi Watch 4 is therefore not the best choice in my opinion.

The watch has ‘more than 150’ sports profiles, including popular sports such as running, cycling, walking, strength training and cross training. However, they are also there for lesser-known sports, such as skateboarding and folk dancing. For running, the watch also has workouts that consist of several steps and provide feedback via audio and vibration signals. It has great functionality, but limited in flexibility and accuracy.

The watch has excellent functions, especially considering the price point. What you miss compared to more expensive, more complete smartwatches, such as the Apple Watches and Wear OS watches, are, for example, offline music playback, a wireless payment option, smart home integration, and maps and navigation. Compared to pure sports watches, such as those from Polar and Garmin, the watch mainly lacks the option to connect external sensors and an indication of fitness progress over a longer period of time. In addition, the touchscreen operation of the Redmi Watch 4 is less pleasant than the button operation of those watches if you have wet or sweaty fingers.

The Mi Fitness app, available for Android and iPhone, provides information on calories consumed, steps, activity, sleep, heart rate, exercise, blood oxygen saturation, sleep, stress and training load. By clicking from the main screen you can delve deeper into the data, including daily, weekly and monthly graphs. You can choose to only store all data locally on your own phone, or to synchronize with the Xiaomi cloud server. The latter is necessary if you want to share data with other services. Mi Fitness offers the option to share health and sports data with Strava, Google Fit and Suunto.

Battery life

A strong point of the Redmi Watch 4 is the battery life. During my test, I achieved up to nine days on a single battery charge with the standard settings. That is considerably less than the twenty days that Redmi promises, but at the same time much better than what you get with an average WearOS or WatchOS watch. In addition, I used the watch intensively during the test period, with several long sports sessions with heart rate and GPS registration. Without exercise, if I extrapolate my data, I would arrive at about twelve days.

I achieved those nine days of working time with ‘smart heart rate measurement’, where the watch takes heart rate measurements at varying intervals during the day and night. I had also disabled blood oxygen saturation measurement and set the screen to ‘raise-to-wake’ mode. With the screen always-on, you can expect your working time to be approximately halved. Charging the watch also goes smoothly. With the included magnetic charging cable and a standard 5V USB charger, the watch is fully charged within an hour and a half.

Accuracy of heart rate and GPS measurement

I tested the built-in optical heart rate monitor of the Redmi Watch 4 against a much more expensive Garmin Epix Pro and/or against a Garmin Edge 1030 cycle computer with Garmin HRM-Dual-ECG chest strap. The latter can be seen as a reference meter.

Redmi Watch 4 (green) and Garmin Epix Pro (red) heart rate recording during an easy run

Redmi Watch 4 (green) and Garmin Epix Pro (red) heart rate recording during an easy run

Redmi Watch 4 (green), Garmin Epix Pro (red) and ECG chest strap (black) heart rate measurement during bike ride

Redmi Watch 4 (green), Garmin Epix Pro (red) and ECG chest strap (black) heart rate monitoring during bike ride with intervals

What is striking after various running, cycling and strength training sessions is that the heart rate values ​​that the Redmi Watch 4 registers always fluctuate significantly. Even on something as simple as a flat-paced endurance run, the heart rate graph is one with many short peaks and valleys. You can live with that if they are all around the actual heart rate, but that turned out not to be the case during my tests. The Watch 4 usually loses track completely, especially with rapid heart rate changes during intervals, but the watch was also way off on more than one occasion during running sessions at a fixed pace. Unfortunately, it is not possible to connect an external heart rate sensor via Bluetooth or Ant+, which makes the Redmi Watch 4 unusable for sports if you attach importance to good heart rate registration.

That’s a shame, because the GPS registration turns out to be very good. The watch uses a normal single-band GNSS receiver that, in addition to the GPS system, can also use the Galileo, Glonass, BeiDou and QZSS satellites. During my runs and bike rides, the Redmi Watch 4 was barely inferior to the much more expensive Garmin Epix Pro with dual-band GPS. Only on small, short bends did I sometimes see a difference to the disadvantage of the Redmi.

GPS recording of the Redmi Watch 4 (green), Garmin Epix Pro (red) and Garmin Edge 1030 bike computer (black)


The Redmi Watch 4 offers surprisingly good value for money. The watch has a suggested retail price of 99.95 euros, but can be found in our Pricewatch for just under 85 euros including shipping costs. For that you get a well-built watch with a nice OLED screen. It also works nice and smoothly. Basic smart functions, such as reading notifications, music and camera controls, and things like timers and alarm clocks, all work fine. Moreover, you can use the Redmi Watch 4 to make hands-free calls via Bluetooth.

Unfortunately, there is something to be said about the sports and health functions. The accuracy of the heart rate monitor is not good and the built-in pedometer also seems to consistently indicate values ​​that are too low. On the other hand, the GPS registration is very good, so if you mainly want to use the watch to log routes, it is an excellent choice.

In my opinion, the Redmi Watch 4 is an excellent choice if you are looking for a smartwatch under 100 euros. The competition in this segment mainly consists of ‘fitness trackers’ with a much smaller and less functional screen, and less all-round functionality. When I look around in the Pricewatch at the time of writing, the first real step up is the (expiring) Samsung Galaxy Watch 4, which is currently for sale from around 125 euros. That is a smartwatch with many more functions and a better heart rate monitor, but also with a much shorter battery life.

The article is in Dutch

Tags: Redmi Watch Review Tweakers


NEXT Dual screen ASUS ZenBook Duo Review