Xiaomi Smart Band 9 review: an accessible and elegant activity sensor

The Xiaomi Smart Band 9 sits in a beautifully crafted aluminum case. Small (46.53 x 21.63 x 10.95 mm), it will suit all wrists, even the thinnest. Above all, it is very light (15.8 g) and is easily forgotten. As with previous generations, Xiaomi offers a large number of bracelets, all rather elegant. The plastic strap feels quite comfortable on the wrist and does not irritate in any way.

On the front, the Smart Band 9 presents a 1.62-inch Oled screen displaying 192 x 490 pixels and up to 1200 cd/m². We must admit that this panel is convincing. It is luminous in all situations, without irritating in the dark. However, you will have to be careful to configure the screen correctly, because the ambient light sensor is not the most relevant and sometimes lets the panel dazzle us. An Always-on screen mode is available, but it increases battery consumption and therefore shortens sensor life.

The Smart Band 9 is waterproof up to 5 ATM. Concretely, this means that the case will withstand a swimming session or a shower, but do not wear it during a diving or surfing session. The pressure changes that would then occur could risk cracking the body of the tracker.

On the Xiaomi Smart Band 9, no buttons! All navigation is done via the touchscreen. Touch it to wake up the panel, slide to the left or right to display the different metrics or settings, from top to bottom, to bring up notifications and from bottom to top to open the main menu.

Within it, around ten apps allow you to monitor health statistics precisely. We find the classics (number of steps, calories burned, daily training time), but also the level of stress, blood oxygen saturation and even the training load. If the manufacturer wanted to imitate Apple’s activity circles, this last metric seems to come straight from Garmin. The weather, calendar or a report on the latest activities are also available.

Of course, due to its size and price positioning, the Smart Band 9 misses out on a large number of cross-functionalities among connected watches. It does not offer a microphone or speaker to answer the phone via Bluetooth, and does not have internal memory to store music. However, it is possible to control what is broadcast on the phone. No NFC chip either for contactless payment.

The display of notifications is summary, but effective. Since reading is obviously limited by the width of the screen, Xiaomi has chosen to scroll through the titles, which slows down the experience. So be careful if you want to check a notification while walking, cycling, etc. Small regret, the majority of available home screens – and there are many – are in English. Not enough to become unusable, but a translation effort would have been nice, especially since all the menus are translated.

The Smart Band 9 synchronizes with the Mi Fitness app (iOS, Android) which is divided into four sections. The first displays all health metrics measured by the activity sensor. You can find the number of steps, calories burned, training and sleep times, heart rate, stress level, blood oxygen level, etc. It is even possible to add your weight manually. (or via a connected scale), your blood sugar or blood pressure to complete the picture. It is finally possible to follow your menstrual cycle, by also adding the data manually. The app thus gives vitality or sleep scores.

The second part is devoted to training. We see the list of activities, a report over a week, a month and a year. The third pane allows you to configure the Smart Band. We carry out updates, choose our home screen from a very, very large list, configure notifications, but also how health metrics are recorded. The user can decide whether heart rate will be measured every minute or every 10 minutes, blood oxygenation on demand or throughout the day, etc. Enough to control the precision of the health check and the autonomy, because measuring everything all the time undeniably reduces the endurance of the device. Finally, the fourth and last part offers some parameters linked to the user profile, nothing very exhaustive.

The Smart Band 9 has a limited number of sensors. There is an accelerometer, a gyroscope, a heart rate sensor and an ambient light sensor. No GPS or barometric altimeter here: this product is not designed for the most tech-savvy athletes. It will therefore be necessary to carry out outdoor sessions with a smartphone in your pocket to have access to a GPS track. We do not recommend relying on the accelerometer and gyroscope alone of the Smart Band 9, the calculated distance very quickly becomes fanciful.

So, what is this heart rate sensor worth? Well, as with the Smart Band 8, its measurements turn out to be of little relevance. Only quiet sessions are sometimes well attended. You can see an output without rapid pace changes below: the Smart Band 9 displays a curve close to that of our reference device, the Polar H10 chest strap.

On the other hand, as soon as the changes in pace are more intense, the activity sensor struggles to keep up.

Tracking errors are ultimately quite regular, so it is difficult to trust this sensor. Below, an imaginary peak at the start of the session.

As mentioned previously, the Smart Band 9 tracks sleep, blood oxygenation and stress levels. However, due to the lack of a dedicated laboratory, we can only indicate that the data collected seem relevant, particularly in terms of sleep.