​Xiaomi Mi Band 4: Essential guide to the new budget fitness tracker

Update: We've now published our Xiaomi Mi Band 4 in-depth review – check that out for our full verdict, or read on for the rundown of the specs, features and release date.

After the many rumours and leaked pics, the Xiaomi Mi Band 4 is now official as the Chinese tech outfit finally unveiled its successor to the Mi Band 3.

The fitness tracker brings a bunch of new features to the affordable wearable and makes some noteworthy changes to the design in the hope that it can fend off the Fitbit and Samsung-shaped competition.

We've finally got our hands on the new Mi Band 4 to put it to the test, but if you want a run down of what to expect from the latest budget fitness tracker from Xiaomi, read on.

Xiaomi Mi Band 4: Design

The Xiaomi Mi Band 4 will feature a new screen and 77 colour faces

So let's talk about those changes in the looks department that Xiaomi has made to make the Mi Band 4 (hopefully) a more enjoyable device to use. Unlike last year's tracker, which offered a 0.78-inch OLED display with 80 x 128 pixel resolution, the new Mi Band 4 instead brings a 0.95-inch colour AMOLED display with 120 x 240 resolution.

That's a 39.9% larger display size according to Xiaomi, so it's quite a sizeable jump in screen estate to view your data on. It's still a touchscreen display as well and it comes with 77 different watch faces to pick from.

Holding that screen in place around your wrist is a 18mm wristband, which is removable just like its predecessor. Interestingly, you can also use Mi Band 3 bands on the Mi Band 4, so you don't need to ditch those old bands just yet.

Xiaomi has retained the same water resistant design, slapping it with a 5ATM rating that means you can jump in the water with it at up to 50 metres depth. This time though, you can track your swimming activity as long as you're in a pool and not in the open water.

Xiaomi MI Band 4: Activity tracking features

There will be a standard and NFC version of the Xiaomi Mi Band 4

Packed into that Mi Band 4 body is a 3-axis accelerometer plus 3-axis gyroscope motion sensors, alongside a proximity sensor and a PPG optical heart rate sensor. There's also Bluetooth of course to sync your data to the Mi Fit companion smartphone app.

These sensors unlock the typical 24/7 activity tracking skills we've seen on Mi Bands before, so step counting, tracking distance and estimating calories burned. There's also automatic sleep monitoring to complete the all day and night tracking.

It also unlocks six workout modes, letting you track treadmill running, outdoor running, cycling, walking and general exercise. There's no GPS on board, so you're relying on those motion sensors to track metrics like distance and pace.

As mentioned, you can now track pool swimming sessions and it has the ability to identify different swimming strokes, such as breaststroke, backstroke, butterfly and freestyle. For swimmers who want advanced metrics, there's a SWOLF score on-board, too.

With the heart rate monitor in tow, you can monitor heart rate 24/7, check in on resting heart rate and get access to charts to help identify trends in your HR data.

Xiaomi Mi Band 4: Smartwatch features

The Mi Band 4 is a fitness tracker first and foremost, but the Mi Band's smartwatch powers have improved with every new iteration. First things first, it is compatible with iOS devices running 9.0 or above and Android smartphones running 4.4 or above of its smartphone OS.

The headline new feature comes in the form of a built-in microphone that will now enable voice commands (and control compatible devices) like smart home tech. There's also NFC for contactless payment support, but both of these features are only available on models bought in China.

It'll dish out notifications from your phone including messages, incoming calls, calendar notifications and app notifications. You'll also be able to view weather forecasts, get notifications about upcoming events and there are watch basics like alarms and stopwatch features.

Another big new feature is the ability to control music playback on your phone from your wrist. Yes, it's been knocking around on other wearables for while, but it's good to see it appear on Xiaomi's budget band too.

Xiaomi Mi Band 4: Price and battery life

The battery has jumped in size from the Mi Band 3, from 110mAh to 135mAh. Xiaomi says this will lead to a 20-day battery life, which is around the same that the previous two generations enjoyed – we'll be testing this out in our full review to see if the bigger battery means better performance.

In China, the Mi Band 4 price has been set at CNY 169 for the standard edition (roughly ), with the NFC variant priced at CNY 229 (roughly ). UK pricing sees the tracker coming in at £34.99.