Smartwatches: Xiaomi Mi Watch versus realme Watch S – Is the higher price worth it?

At first glance, the two large watches look very similar with a uniformly dark design. They both feature straps in the standard 22 mm size with a quick-release buckle that can be exchanged as desired. In terms of case color, only Xiaomi offers dark blue or beige alternatives. The case of the Xiaomi Mi Watch is made of plastic, while that of the realme Watch S is made of aluminum and is marginally lighter. The Watch S is certified according to the IP68 standard, and the Mi Watch is water-resistant up to 5 ATM and consequently certainly suitable for swimming.

The display is not entirely flat in both devices: Xiaomi rounds it off towards the edge, while realme gives it a slanted bezel towards the edge. One thing that is not noticeable at first glance is that although the Watch S is still slightly larger than the Mi Watch (1.81 inches) with a diameter of 1.85 inches, its display is smaller than in the Mi Watch (1.39 inches) with 1.3 inches between the wide bezels. With a resolution of 360x360 pixels, the Watch S only achieves 278 ppi. The Mi Watch's pixel density of 326 ppi is on par with other smartwatches of this size such as Huawei's Watch GT 2 Pro or the Mobvoi TicWatch Pro 3.

In addition, the AMOLED display of the Mi Watch makes the watch faces look brighter than on the realme Watch S. The design options are extensive in both devices with more than 100 watch-face variants, but both lack the option of customizing them. An update following our review of the Watch S added the option to change the watch face not only via the app but also directly on the wrist, just like on the Mi Watch.

Both regulate the display brightness automatically with the help of a light sensor. Only the Mi Watch has an always-on display. Since neither of them has NFC, they don't support mobile payments via the smartwatch.

The corresponding smartphone app for the realme Watch S is only available in Google's Play store, so you won't get far with an iPhone. Xiaomi's Wear app is available for both platforms; however, the Xiaomi smartwatch behaves differently under iOS than under Android in some situations, which we point out in our review of the Mi Watch.

Both wearables are controlled via the touchscreen and two buttons on the sides. The lower button launches the workout app on both devices, or alternatively a previously assigned workout on Xiaomi.

Xiaomi installs a few more apps on the Mi Watch than realme on the Watch S as the following app overview shows. The realme apps are also found on Xiaomi, including a timer, alarm clock and stopwatch, breathing exercises, a workout app, and the latest workout logs as well as remote controls for the smartphone music player and its camera. The latter is still in Beta status with Xiaomi. In our review of the Mi Watch, it worked with the iPhone 12 Pro and an Honor V20, but that might not be transferable to all manufacturers.

In addition to the suite of tools, we find apps for the compass and the altitude sensor on the Mi Watch, which the Watch S lacks, as well as apps for extended health monitoring, another feature that the Mi Watch offers that the Watch S does not. More about that under the Health and Fitness section.

Heart-rate monitoring is among the standard features of a fitness tracker. In view of this, it's surprising that both the Mi Watch and the previously reviewed Mi Watch Lite measured pulse so inaccurately in our tests. Compared with a chest strap from Polar, both often registered 10 beats more or less. Although the realme Watch S wasn't always in line with the chest strap either, the deviation was smaller, and the measurement was more stable overall. Both issue an alert if desired when the heart rate is outside the norm. In the realme app, you can define the limits for this alarm and also adjust the measurement interval.

Both measure blood oxygen saturation levels manually, and at night during sleep, they don't do several automatic measurements like the TicWatch Pro 3 or the Fitbit Sense, for example. Comparison measurements with a medically certified pulse oximeter show that the realme Watch S has a high level of compliance and a low average deviation of 0.7 percentage points. With the Mi Watch, the average deviation was of 1.2 percentage points.

While the Watch S limits activity tracking to basic functions such as movement reminders, step counting, and calorie consumption, Xiaomi expands the Mi Watch's health functions to include an energy indicator and stress barometer, among other things. In combination with the iPhone, it synchronizes health parameters like sleep data and activity energy with Apple Health. Neither device connects to Google Fit.

The Xiaomi tracker automatically detects running and fast walking. When working out using the training app, both control the smartphone's music player without having to leave the workout screen. As a workout assistant, the Watch S is significantly inferior to the Mi Watch. It has neither GPS nor an altimeter and only tracks the route when running or cycling in combination with the smartphone. Its training app only supports 15 sports compared to over 100 on the Mi Watch.

Users who use the Xiaomi tracker for their daily workout will also appreciate the professional analytics and the fact that the lower button opens their preferred workout mode if desired and not the top-level workout app instead.

The benefits of health and fitness tracking ultimately also depend heavily on how the manufacturers present the data. This is documented in the review of the Mi Watch and the review of the Watch S with numerous sample watch and app screenshots in each case.

The manufacturers estimate the average runtimes of their wearables to be almost the same: 15 days for the Watch S and 16 for the Mi Watch. However, we only managed about 10 days without the always-on display in our real-world tests with the Mi Watch, and 4 to 5 days with the always-on display enabled.

The realme smartwatch lacks both an always-on display and GPS; overall, it proved to be more energy-efficient in our review. In the test, the battery lasted rather longer than stated by the manufacturer. A killer feature is the wear detection that realme implements via a sensor in the Watch S, at least if you value being able to rely on the smartwatch for as long as possible, even if you don't wear it permanently. In this case, the realme Watch S reduces its power requirements to such an extent that the battery of our test device survived the 3 months between our review and this comparison. With a remaining capacity of 10, the watch was immediately ready for use.

The realme Watch S and the Mi Watch aren't officially available in the United States, but you can already find them on ebay. The realme Watch S has several listings starting at $100. Moreover, the Xiaomi Mi Watch has some listings here too that start at around $125. If you prefer, you can also wait for both devices to pop up on Amazon.