Featured Review: Xiaomi Mi4


Xiaomi has been an up and coming competitor in the Chinese market for a few years now, and it all started with its custom version of Android simply titled MIUI.  Back in the Gingerbread days MIUI was the bastion of innovation, bringing things to the table like real-time lyrics when playing music, custom lock screens, a powerful theme engine that themed the whole user interface, and whole slew of other goodies.  One of the biggest simultaneous draws and drawbacks to MIUI, however, was its clear design after Apple's own iOS, something that some Android users loved and plenty of others hated.  Android is different than iOS in so many fundamental reasons it's striking when switching back and forth between the platforms, but MIUI tries to bridge that gap by creating a sort of hybrid between the two, and Xiaomi's latest flagship phone isn't any different in that regard.  The Mi4 is a top-end 5-inch Android phone with a super high quality built that appeals to the aesthetics of a 4th generation iPhone, but places plenty of other design elements from various Android phones into the mix as well.

Then there's the fact that Xiaomi launched its brand new flagship phone with the same old version of MIUI that the Mi3 runs, but did something rather unique; the beta for MIUI 6 began as soon as the Mi4 came out, and while Xiaomi plans to launch the new and improved OS next month, users can try it out right now with relatively little pain.  All this comes together in an incredibly unique experience that has brought me to review the Xiaomi Mi4 a little differently from other phones.  This review is going to focus on the phone you're going to get today if you ordered it, pre-packed with MIUI 5 running Android 4.4.2 KitKat, and my next review will focus on what's changing in MIUI 6 and how that improves (or doesn't) the shortcomings of the phone.



  • 5-inch 1080p IPS LCD
  • Qualcomm Snapdragon 801 processor clocked at 2.5GHz
  • Adreno 330 GPU
  • 3 GB of RAM
  • 16 or 64GB internal storage, no microSD card support
  • 3000 mAh Li-Po battery
  • Android 4.4.2 MIUI 5
  • 13MP Sony Exmor IMX214 rear-facing camera, LED flash
  • 8MP Sony Exmor IMX219 front-facing camera

As you can see from the specs it matches every other flagship phone out there in every single department, and even bests most with the camera sensor.  There are a few phones now that feature this sensor, notably the OnePlus One and the Oppo Find 7.  The battery is large for the screen size, but the physical dimensions of the phone still fall within normal range of todays' thinnest phones.  Right now the Mi4 only comes in a WDCMA variety, but an LTE version is planned to come out soon.  I'm running the Mi4 on T-Mobile's network here in the US, and it's just as good as other non-LTE phones I've used in the past, but here's the whole list of spectrums the phone supports so you can see if it works where you live:

  • HSPA 850 / 900 / 1700 / 1900 / 2100
  • GSM 850 / 900 / 1800 / 1900



The Mi4 features a 5-inch IPS LCD panel with great brightness levels, which results in fantastic viewability in sunlight, and extremely good viewing angles.  You can literally look at the phone from the side and it's still just as clear as viewing from the front, and you don't get any of that weird color variation when viewing from the side that some types of displays exhibit.  It's also a 1080p display so seeing pixels is nearly impossible unless your face is right up to the display.  My problem here is with the saturation levels, which are about as crazy as anything from Samsung's AMOLED displays.  Bright colors tend to have a neon glow to them, and overall the saturation levels were too high no matter what I changed in the software settings Xiaomi provides.  While this gives the screen an immediate wow factor, the colors are just plain inaccurate.



Hardware and Build


What seems to be an afterthought for some phones out there was clearly the first thing Xiaomi thought of when it designed the Mi4.  Right out of the box you'll notice striking similarities to the iPhone 4/4s, and plenty of differences too.  The frame around the edge of the phone is metal and feels smooth and cold to the touch.  You'll find the upper edge of the metal to be chamfered, which creates a great aesthetic to match the perfectly flush screen on the top.  There are no protruding bezels here, although the back does have a very slight curve to it that you won't see on an iPhone.


Speaking of the back the Mi4 ships with a fairly standard slippery, shiny plastic back in either black or white, but Xiaomi has made the back completely removable and are even planning on selling over a dozen different replacement backs that feature materials like leather, fabric and plenty of others too.  This is a fantastic design that gives the user significantly more options in customizing their phone other than just the software.


The build quality of the phone is second to none too, and is an absolute joy to hold in the hand.  The device feels incredibly solid and has a really nice weight to it; not too light, not too heavy.  This weight makes it feel more substantial than some other plastic phones out there, but it's not so heavy that you're going to have a tired arm after being on the phone for an hour.  My biggest problem with the design is that since Xiaomi is using a metal frame, which inherently has almost no friction to it, and also uses a nasty slippery back, this thing is going to fly out of your hands once the humidity drops from the summer weather.  I would absolutely recommend getting a case for it until Xiaomi releases the additional backs, which is a crying shame considering how beautiful the device is.


The size of the device is phenomenal and is super easy to use with one hand.  Being someone who prefers a phablet sized device normally it was actually refreshing to use the Mi4's 5-inch screen, and since there are super minimal bezels here the device felt really good in the hand.  I've got no problem reaching every corner of the screen and typing one-handed too.


On the front of the phone you'll find three capacitive buttons in a very Samsung-like arrangement of menu to the left, home in the middle and back button on the right.  These behave exactly as you would expect and offer no tactile response other than a vibration when pressed.  The buttons on the side of the phone, however, feel fantastic and are made of the same metal that the frame is, giving a quality click when pressed.  My issue here is that they are both on the same side, and on the right side of the phone no less, meaning unless you're a left-handed individual these buttons are not comfortable to find when talking on the phone as I had to constantly thumb around for the volume rocker in a very awkward position for my thumb.


The top of the phone features a standard 3.5mm headphone jack and what looks to be an IR blaster, although there was no IR blaster software included with the phone, and 3rd party apps I tried to use didn't do anything.  The bottom of the phone features a nice, loud single speaker that's super clear and didn't rattle at all for me, even on max volume.  Next to it is a standard USB 2.0 micro USB port for charging and interfacing with computers.


Performance and Memory

Performance here is the same as you're going to find on any flagship nowadays.  Android 4.4 KitKat is smooth as ever, and although Xiaomi has disabled the ability to switch to the faster and smoother ART runtime, the good old Dalvik works just find no matter what you're doing outside of the usual hiccup here and there that Dalvik has always exhibited.  Games all flew by at smooth framerates, and I never had a performance drop outside of Dalvik's inability to scroll through lists smoothly.


RAM usage is pretty perfect too.  On the initial setup of the phone I had a lot of weird problems with apps force closing, apps running in the background like Google Now getting killed to free up RAM, etc.  All of these were solved after a factory reset, and I was extremely glad because I couldn't imagine a phone with this much horsepower having such difficulty running modern Android.  Multitasking was a breeze; jumping between apps is instant and there's never any reloading of applications since there's so much memory to work with.  Even image heavy apps like Hangouts or Chrome never got killed, which is something to really appreciate.

The version I have comes with 16GB of internal storage, which is super small nowadays and won't hold a whole lot, and unfortunately without microSD card support there's no way to expand this storage at all.  Thankfully Xiaomi sells a 64GB model for just $50 more, which is completely worth the price given how much more storage that is compared to the price you pay for it.  On the bright side keeping SD cards out of the equation makes file management much easier, so there's no guessing at where the picture you just took or downloaded was saved to.



Battery Life

Given that the Mi4 "only" has a 5-inch screen but still features a battery the size of most phablets, you can bet that the battery life is phenomenal.  In my time of testing the best I got was nearly 5 hours of screen on time, over an hour and a half of talk time, streaming music to a bluetooth speaker for nearly 8 hours and even an hour of using my GPS via Runtastic.  At the end of an 18 hour day it still had 12% battery left, and if I turned on battery saving mode this would likely have gotten me through the rest of the night if I used it conservatively.  This is as good as I've gotten with any phone I've ever used, and the other days of use were similar in battery life.  I've even got an Android Wear watch connected all day too, so that's an extra drain given that it's constantly syncing and using the bluetooth radio.  You're not going to get much better battery life than the Xiaomi Mi4, that's for darned sure!




Here's where the big test comes in, as the hardware is feels phenomenal, built well and downright gorgeous too.  Software really makes the experience last though, so no matter how good of hardware you've packed in those daily annoyances with software will ruin an otherwise perfect phone.  This was where I had the biggest problem with the Mi4, but most of it is down to preference, so let's break this down by section.


The visual user interface looks like a mashup between iOS and Android, with the menus and navigation feeling much more iOS than anything.  The lockscreen style depends on the theme you're running and can vary wildly between just a slide to unlock style to one with multiple app shortcuts.  All the lockscreens I tried with lockscreen music supper were super disappointing because they didn't feature full-screen album art, and in some cases no album art of any kind.  While most lockscreens you can choose in the theme engine don't have any shortcuts to find to quickly jump into your most used apps straight from the lockscreen, there was a nice system hook for holding down the home button while on the lockscreen to toggle the flashlight.  Pressing the power button will shut this off and was a very convenient way to use the flashlight when I needed it.

Moving onto the home screen you'll find, again, a mix between iOS and Android.  There's no app drawer here to be seen at all, so all the icons and widgets you have will be on the desktop, switching between pages to see everything you've got.  Since this is Android you can generally choose your home launcher to be whatever you want it to be, but I found some issues.  First of all I couldn't use the Google Now Launcher at all; even when it was installed I didn't have the option to set it as my default.  Secondly you lose many of the theming abilities when not using the built-in launcher, and it felt disjointed when only having parts of the OS themed and not others.

The settings menu holds two tabs: one for quick settings like ring tones and wallpaper, and one for all settings.  Dragging down the notification shade actually looks like a mix between iOS and HTC's Sense 4 UI from years ago.  It features only single line notifications under most circumstances, and has to be grabbed with two fingers and dragged down to be expanded instead of the single finger expansion Google introduced back in Android 4.3 Jellybean.  This is unfortunate and downright annoying, as the change was made for good reason and there's no good reason to go back to it.  I did like Xiaomi's version of quick toggles though, as you can swipe left and right on the notification drawer at any time to go between quick toggles and notifications, and on top of that Xiaomi is using a much more Google style of quick toggle than Samsung or LG, for example.  This means the quick toggles actually give you information instead of just being quick buttons, so it'll tell you things like what WiFi connection you're currently on, mobile network, etc.

There are also a number of very sensible placements through the UI, things like clicking the clock in the notification bar takes you to the Clock app, or clicking the date takes you to Calendar.  Holding down long press even gives you a quick button to clear all apps, something not done on most Android phones.  Speaking of multi-tasking, the interface is interesting but ultimately archaic and takes us back to the Gingerbread days.  Long pressing on home brings up open apps, listed in a horizontal row of icons paginated with 4 icons per page.  This makes it truly difficult to quickly multitask because you not only have to hold down the home button for 2 seconds to get to this interface, but you also need to remember what the app's icon looks like with the theme you're using.  On the positive side swiping down actually locks the app into memory, which is something unique that I've never seen before on a phone, which was cool especially if you've got a bunch of apps open and want to prioritize what gets closed and what doesn't.  Swiping up kills the app, but again without an actual preview of the way the app last looked it's annoying to figure out what needs to be closed.


You can change pretty much every aspect of the UI through MIUI's powerful theme engine, and if MIUI has innovated in any way in particular it's with the theme engine.  There's only one other phone on the market not made by Xiaomi that can do this too, the OnePlus One, but since that's CyanogenMod it's handled very differently.  MIUI uses its own theme store that categorizes themes by paid and free, popular and new, and even in themes like nature, cars, etc.  From there if you like only parts of the theme you are using but would like to change others, like the icons for example, you can go into the specific components section of the theme manager and change practically any individual part of the UI.  It's powerful and unique, and being a community driven marketplace there are plenty of themes added and updated all the time, although you'll find that the best ones are likely ones you have to pay for.

Sort of related to themes is the store for all sorts of media that Xiaomi provides.  In addition to themes Xiaomi provides a ton of different wallpapers and sounds that rival even that of Zedge or another big app that provides similar content.  There's plenty of both free and paid versions of everything, and I didn't find that the quality of the free ringtones or alarm sounds were any better or worse than the paid ones.  The biggest obstacle for me here was down to a language barrier, as even though I have my system language set to English much of the store is in Chinese, but it's possible to navigate the store if you just take your time and look around at the icons and other visual cues.


Xiaomi Apps

Every non-Nexus phone always comes with its manufacturer's own set of unique apps that add features to the phone, and the Mi4 is no different.  MIUI has its own set of apps like sound recorder, compass, FM Radio and others, and they are all included here too.  Xiaomi has added a number of little tactile feedback hints throughout the UI that just make the phone feel really good when using it.  There's something oddly satisfying about the phone vibrating lightly when it ticks through the minutes on the analog clock, or that very distinct clicking vibration when adjusting when your alarm is going to go off.  There are also other simple things like swiping through text in the notes app to cross through the text or to undo that action.

In some apps when you long press to edit text there's a large magnifying glass that pops up to give you a better close-up view of where you're dragging, and I found highlighting text to be a little more responsive on the Mi4 than on many other Android phones I've used.  There are also some Xiaomi apps that support pop-up windows, such as the notes or messaging apps, which help with multitasking while using features that often require you to switch back and forth between apps.  It's not quite as well done as the pen-window feature on the Galaxy Note series, for example, but it's better than most other phones because this sort of thing just isn't usually offered out of the box.

Security and Data Management

China's network topology is a unique one, and like many countries in Europe or Asia the cost of data is very high.  Because of this MIUI features some incredible data management that lets you not only set a monthly limit for data and give you alerts when you've used a certain percentage, but it also lets you fine tune these settings per app.  In the data management app you can select whether specific apps are allowed to use WiFi, Cell Data, both or neither at all, which really helps when you have an app that likes to go rogue and eat up data.  By default the data management is a little overly aggressive though, and I found myself needing to turn it off altogether because I couldn't even download apps from the Play Store on WiFi.

Security is second to none here, and I was incredibly impressed with the app permissions management in the system.  While the Play Store lets you know what apps are allowed to do when you install them, I'd wager that most people don't even read these permissions when they download them.  In MIUI when an app asks to access data outside of itself the OS asks you whether or not it's OK, and gives you the option to always allow this action if you trust it for that particular app.  This prevents apps from getting ahold of data you might otherwise not want them to, like reading your contacts list or GPS position.  This was refreshing to see on a phone right out of the box, and a great alternative to something like permissions management found in CyanogenMod since it automatically asks you rather than you having to dig around and find the setting.

Cloud storage is a big thing for phones anymore, and Xiaomi's cloud offerings might just be the best and most coherent set I've ever seen.  More than just data syncing data and backing up photos, MiCloud gives each user 10GB of free storage to store contacts, call logs, messages, photos, browsing data, music and more.  There are a ton of other system apps including DouKan Reader that sync your eBooks and the like as well, and the messaging app actually works over the cloud too by pairing your SIM card with the service, allowing you to use the MiCloud web interface to interface with your phone and send messages too.  It's a fantastic service that rivals all others.


Phone Calls and Network

Phone calls were as good as they come, especially in HD voice.  The clarity of the audio that comes out of the speaker is absolutely top notch, and like any good HD voice call it felt like the person was right next to me rather than talking to me on a phone.  The speakerphone is fantastic too, and provides a much louder and clear experience than I am used to on most phones.  Having the main speaker on the bottom of the home helps with acoustics too.

Network speed was also about what you would expect from a non-LTE phone.  T-Mobile has arguably the best HSPA network in the US given that they were the only ones that took the tech seriously before their LTE rollout, and it shows even in congested areas.  The best I could pull down with the network was around 12mbps down and 1.5mbps up, which is really more than enough for most mobile content.


While cameras always get the biggest showcase in most reviews, music playback is likely something that most users will use more often than anything else on their phone.  I'm happy to say the music playback on the Mi4 is nothing less than excellent, but it's still not quite the best I've ever heard from a phone.  Even still it bests most phones, if for no other reason than the powerful equalizer and heaphone optimization that Xiaomi uses in the OS.  When you plug in headphones you are prompted to customize your listening experience, which will take you to the equalizer section of the music app and lets you not only choose from preset equalizers, but also create your own and save them, as well as select what type of headphones you use.  You can choose from generic earbud or in-ear headphones, as well as various Xiaomi branded ones to adjust the music to better fit those speakers.  Definitely don't turn this setting on if you aren't using what's listed though, as it does all sorts of funky things to the music when listened to through a car system, for instance.



The Xiaomi Mi4 doesn't have OIS, so while it's got a disadvantage in the video category right out of the box when compared to an LG G3 or something, most phones don't have hardware stabilization, so odds are you won't notice the difference if you haven't used a phone with OIS before.  Xiaomi has taken full advantage of the Sony Exmor IMX214 sensor that's behind the lens by giving extra options like HDR video and super slow-mo video.  Time-lapse video is also present, and gives you the ability to change it from 1-second per shot all the way to 60 seconds per shot.  You're going to need a tripod or something else to hold the phone still to actually use this feature though, so I won't spend anymore time on it.  Slow-mo video is pretty standard fare nowadays, providing up to 120FPS at 720P resolution, and competes with the best of the slow-mo phones out there at the same resolution and speed.  There's unfortunately no way to choose framerate though, just normal, slow or fast, so you don't necessarily know what you're getting into before you hit start.

HDR video is flat out amazing looking, and provides an excellent way to record video in bright conditions with lots of shadows and contrasting lighting conditions.  It's also good indoors but with lots of light, so during the day is fine, but the noise ramps up exponentially as light sources decrease.  Noise in auto mode is much better in low light situations, and actually seems to be reduced with 4K video over the lesser options.  Speaking of 4K recording, you can even record HDR video in 4K, meaning quality is never a problem, just choosing the best mode based on the light at hand.  Audio recording was less than stellar though, and often I'd hear what sounded like wind blowing into the mic interrupting whatever sounds are supposed to be there.  Hopefully this can just be fixed with a software update.



As I've said before the Mi4 uses Sony's latest sensor, which can also be found in the OnePlus One and the Oppo Find 7, and is chock full of all kinds of new features to 2014.  HDR is the biggest selling point of the IMX214 and it does a better job at processing HDR than basically any other sensor out there.  It can even do Live HDR, which gives you a live preview of what the shot would look like and takes an instant HDR-like shot.  Before we get into the nitty gritty of the pictures themselves though, let's go over the software.

The interface presented should be very familiar, and isn't really any different from the interface found on practically every phone out there at this point.  The Mi4 offers a simple and advanced mode, but defaults to simple mode which offers a few big options and not much in the way of tweaking the shot.  Advanced mode opens up a whole slew of options that lets you even manually adjust ISO up to 3200, and shutter length up to 1 second.  This gives some seriously powerful tools for night mode photography, but doesn't quite provide some of the insanely long shutter lengths offered by the OnePlus One or Oppo Find 7.  However a shutter length of 1 second is actually usable with your hands and won't require a tripod if you have particularly steady hands or prop the phone up on something.

Exposure control and focusing is nothing short of brilliant too.  Like every other touchscreen camera on the market you click on a place to focus, and the phone then does its thing.  How the Mi4 differs is that instead of just showing a crosshair or a little circle where it focused on, you'll find that the circle is now a button to take the picture.  Click to focus, click again in the same spot to take the picture.  No need to move your thumb around or move the phone, or even click a physical button and risk shaking your device.  Not only that but the ring is an exposure control ring too, so rotating it in a circle to the left pushes the exposure bias negative, and rotating to the right makes it positive.  This came in handy often since auto focusing usually tends to over expose shots, and especially in HDR mode tending towards a lower exposure bias produced a picture that was much more visually appealing.

Xiaomi has added an interesting new flash mode that is automatically done when the light gets low that blends a regular shot with a shot taken with flash to create a more visually appealing and less harsh photo.  Obviously there's a huge difference in a dark room when taking a picture with and without flash, but I found it difficult to tell whether or not this mode was working or enabled.  Most of the time I preferred the shot without the flash though, as flash almost always produces a super harsh picture that's not worth looking at after the fact.  I found that adjusting the ISO and shutter speed to maximum in truly dark situations produced an excellent image that was worthy of looking at on any screen size; just make sure you don't have moving objects or move the phone at all.

There's also an awesome refocusing mode that takes a few seconds to take, but ends up taking a handful of photos at a time with different levels of focus, allowing you to refocus the photo in the phone's gallery.  This mode is found on plenty of other phones nowadays, but it's worth mentioning since the execution is done so well.  On top of that Xiaomi offers object tracking within the camera to keep things that are moving in focus.  Much like you would draw a selection box with a mouse on a computer, you press, hold and drag down to a corner on the camera interface to draw a box around a moving target.  This worked very well in my trials and followed the object no matter how fast.

I found the HDR algorithms to be superior to anything I've used outside of the Nexus 5's HDR+ mode.  Scenes with super bright and super dark objects still gave me plenty of visual detail in both parts of the scene, whereas most cameras' HDR modes overexpose the shot or don't underexpose enough, leaving areas too bright or too dark to be called a sufficient HDR shot.  Colors were punchy but not over saturated, and the scenes overall were striking and beautiful.  My problem ends up being the same here that it is with Samsung cameras; the pictures look excellent on a phone or even a tablet, but once you start putting them on 24-inch monitors or TVs they start to fall apart.

Anti-noise filters kill any detail that would have been present normally, and sticking to a much lower ISO bias to eliminate noise forces the shutter to stay open longer than necessary, causing blur and other issues, especially in low light situations.  HDR mode sees this a lot too, with the shutter staying open too long and often getting ghost images on moving objects within the frame.  I've got mixed feelings on the camera here, simply because the processing found in the HDR algorithm and the rest of the software features are not only good, they are incredibly useful and not gimicky at all.  My issue here is that Xiaomi's anti-noise filters tend to be overdone, and while they aren't as extreme as what's found on Samsung's cameras (which is the saving grace here), they don't produce quite as clean of an image as the OnePlus One does.  While I'm notoriously harsh on cameras and the results they give, I like to use my pictures as wallpapers and prints, so if you're just looking at these on a phone or a tablet you won't complain, but check the sample shots and judge for yourself.

mi4-t-01mi4-t-02 mi4-t-03 mi4-t-04 mi4-t-05 mi4-t-06 mi4-t-07 mi4-t-08 mi4-t-09 mi4-t-10  mi4-t-12 mi4-t-13 mi4-t-14 mi4-t-15 mi4-t-16 mi4-t-17 mi4-t-18 mi4-t-19 mi4-t-20 mi4-t-21 mi4-t-22 mi4-t-23 mi4-t-24  mi4-t-26  mi4-t-27mi4-t-11mi4-t-25



For around $400 Xiaomi Mi4 will sell you the 16GB Mi4, and for around $50 more you'll get the 64GB version.  You're getting a phone with top-of-the-line specs and a truly top-of-the-line build with interchangeable back plates.  Xiaomi's Android skin, MIUI, offers tons of features that lean toward security and user experience, often spelling things out more than some other Android skins would and placing intuitive options in places that make sense.  While the interface is a little too reminisce of iOS for my liking, some may truly enjoy this fusion of iOS design with Android's powerful back end OS, as it brings more options to the table than Apple will likely ever allow.  Speaking of options the theme engine Xiaomi built into the Mi4 allows you to choose from thousands of options on their marketplace, and change out nearly every part of the OS piecemeal to create your own perfect theme.

Music playback is near the top of the game with an excellent equalizer and the ability to save presets, and the camera has some of the best software I've ever seen on a smartphone, with a powerful and easy to use interface.  This unfortunately doesn't translate into better pictures though, as with many Samsung phones you'll find that looking at the picture on your phone looks incredible, but doesn't look quite so good when blown up on a monitor or TV.  Performance is top notch, and while multi-tasking needs a serious overhaul you won't be waiting for apps to load or worry about anything reloading when you haven't used it in a while.  Battery life is also killer, and exhibited some of the best battery life I've ever seen on an Android phone.

MIUI 6 is on the cusp of release and promises a full overhaul of the OS with added features and reworking of plenty of sections within the UI, and Xiaomi has a good track record of keeping its phones updated too.  With all of this in tact I can whole heartedly recommend the Mi4 if you like Xiaomi's services and interface, but if you're a more stock Android user and prefer Google's services you're likely going to want to stay away, at least from the stock OS.  Stay tuned for the MIUI 6 review in the coming days and find what changes Xiaomi has made for the better!  If you don't have your own Xiaomi Mi4 you can buy the 16GB version here, and the 64GB version here.