In the last few years, we've witnessed a big change to the way the smartphone market works. China has become both the biggest smartphone market on Earth and home to some of the most interesting smartphone companies. Lately, all the cool and crazy smartphones seem to be launching in China first and then maybe (or sometimes never) in the rest of the world. This includes devices like the all-screen Oppo Find X with its crazy motorized pop-up camera. Earlier, you might have had an eye on the original Xiaomi Mi Mix, the phone that kicked off the slim-bezel smartphone craze.
With the United States often taking a backseat in the worldwide smartphone market, you might be tempted to import one of these exotic foreign smartphones. You can almost always do it—either through a random Chinese smartphone site or sometimes even on Amazon.com. The question is, though, should you? Importing a smartphone will result in a number of challenges, so there are a few things to think about.
The biggest problem you'll run into is with cellular connectivity, where a foreign phone might not work on your local cellular network. Each carrier has a set of LTE bands that it operates in, and while phones sold in the US are usually careful to hit the right carrier bands, Chinese smartphones might either not work on your carrier at all or work with reduced connectivity. Droid Life has a nice cheat sheet here for US networks, and you'll need to compare that to the spec sheet of each individual phone. The general answer is that you have a chance with GSM carriers like AT&T and T-Mobile, and Verizon is getting better thanks to VoLTE (Voice over LTE) which removes the need for CDMA. You'll have a much harder time with Sprint.
Some Chinese OEMs like Xiaomi and Oppo are moving into Europe, which means wider LTE compatibility and a better chance of US compatibility, so things are getting better. Also keep in mind that phones can have variants for different regions, so make sure the version you're buying has the bands you need.
If you're really desperate, the phone you want should work on Wi-Fi no matter what, which means it should work at home or at the office. That also means just carrying around a hotspot is an option, too.
The Play Store and bootloader barriers
Strictly Chinese smartphones, or phones that come with a Chinese-region build of software, are going to be a problem. Google doesn't do much business in China, so Android phones from China won't come with the Google apps. This means your phone won't have the Google Play Store, so you'll have a hard time accessing most of the Android app ecosystem. Restoring the Play Store isn't as easy as downloading a Play Store APK and installing it on your device—most Google apps rely on myriad other supportive Google apps for things like background syncing, cloud messaging, and logging in. Just installing the Play Store APK won't work.
Getting the Play Store to work on a non-Google build of Android is tough. Downloading the requisite Google apps to a PC is easy—opengapps.org maintains an up-to-date package of the latest Google apps for download, available in various flavors for every combination of CPU architecture and Android version out there. The problem is installing them on a phone. Some of Google's apps need system-level permissions to work, so they need to be installed as system apps, which normally a user isn't allowed to do. Your Chinese Android phone will need an "unlockable bootloader," which is basically an on/off switch giving you full control over the phone software. With an unlocked bootloader, you can boot into a recovery mode and modify the phone so that you can get system-level permissions and install the Google apps you need.
Whether or not your phone has an unlockable bootloader can be hard to even figure out. It's usually not on the spec sheet, so you'll need to hope someone technical has posted the information on the Internet somewhere. A good place to check is the XDA Forums, which are meticulously broken down by individual phone model. Just search for your particular phone and see if other people are making progress on modding or unlocking the bootloader and/or rooting the phone.
Chinese companies have been pretty good in the past at providing unlocked bootloaders, but lately they've been throwing up barriers due to security concerns. As we experienced firsthand when we imported the Xiaomi Redmi 3, smartphone retailers aren't necessarily trustworthy. In our case, the reseller opened our device, unlocked the bootloader, flashed the Google apps to the system partition, put the phone back in the box, and sold it to us as unopened and "new." At least, we hope that's all they did. Who really knows? The scary part is we didn't even notice our phone had been tampered with when we received it.
So to stop retailers from mass unlocking and modifying consumer devices, some companies require a code or PC program to unlock a bootloader, sometimes with a waiting period. Xiaomi, for instance, requires that you "Apply" for an unlock code by making a Xiaomi account, logging in, and downloading the "Mi Unlock Tool." After plugging into a PC and running the tool, you'll either get confirmed or denied for an unlock code, and then there might be a waiting period before your code arrives. This wait period has ranged from two days to as much as two months. Huawei has shut down bootloader unlock requests altogether.
Google has started to clamp down on sideloaded Google apps, too. The company recently threw up a roadblock for "uncertified" Android devices that originally didn't ship with the Google apps. Just like with Xiaomi's unlock process, this requires jumping through some hoops so you can be tracked and judged. Google's instructions require you to have the Android developer tools installed and a rooted device, and then you have to run a command to grab a Google ID and submit it to Google while logged in to your Google account. If you have personally flashed Google apps to your Chinese smartphone The Right Way, you will have done most of this work already, but it would be a pain for an unscrupulous phone seller.
Your best bet would be to try to import a Chinese phone from anywhere other than China. Does it also sell in India or Europe? Aim for that version. Anything that isn't from China should have the Google apps pre-installed, and that will save you a ton of headaches.
To ROM or not to ROM?
If you get a phone with an unlocked bootloader, another option is wiping out the existing software altogether and flashing a new software package—called a "ROM"—usually pieced together by someone in the community. ROMs can focus on either starting with the existing software package and changing pieces of it, or they can throw out the whole OEM software package and start with stock Android. Chinese Android builds are almost always lame iOS clones, so a stock Android ROM can give you a more normal and consistent Android experience. ROMs based on the pre-installed software can focus on speed improvements, customizability, or removing crapware.
The hard thing with aftermarket ROMs is maintaining the functionality and stability of the pre-installed software package. Google did a lot of great OS portability work with Android 8.0's Project Treble, so today most new phones should be able to take a stock Android ROM and boot up to the home screen. XDA has a whole forum dedicated to Project Treble, and every ROM here should—in theory—be universally compatible with any phone that was built for Android 8.0 and up. Problems might arise when it comes to hardware support outside of the usual basic smartphone functionality. Specific camera features or odd hardware additions like a pop-up camera or heart rate monitor might stop working with a purely Treble-based ROM.
Again, you're hoping someone on the Internet has already come before you and run into these problems. Popular smartphones should have a decent community on their XDA sub-forum that has worked to solve the various compatibility problems that pop up. It's always worth taking a look around a phone forum before you commit to buying an import.
Hopefully, this will get better soon
The current wave of Chinese-centric smartphone companies will hopefully take a more worldwide approach to launches soon. All the major players are working to expand outside of China, usually targeting Europe first. The US can be tough to break into thanks to the carrier-centric market, the litigious nature of the established smartphone players, and distrust of the Chinese government, but companies like Xiaomi and Oppo constantly claim they're intent on breaking into the US market in the future.
For now, you can either deal with the headache of importing a phone and trying to whip it into shape yourself or just dream of these crazy smartphone designs from afar.