Small battery capacity and in-display fingerprint sensor disappoint
Xiaomi's Mi 9 is a pretty decent smartphone for around $500 USD, which should be no surprise coming from Xiaomi. The company routinely puts out some pretty good devices, with the latest specs at a pretty low price. The Mi 9 is not Xiaomi's high-end flagship though, that is saved for the Mi MIX lineup now. The Mi 9 is more of a "safe" phone that anyone can buy, and be happy with.
Disclaimer: Android Headlines reviews are designed to cover both the "good" and the "bad" perspectives of all major phones. This was designed to give our readers the good and the bad, separately, instead of it getting lost in the shuffle. This "bad" review focuses on things that would be negative for the Xiaomi Mi 9. If you are specifically interested in the positives of the Xiaomi Mi 9 check out our full good review.
The Mi 9 is outfitted with a pretty small capacity battery, especially in 2019. Though, it's important to note that battery capacity alone doesn't mean good or bad battery life. Xiaomi has done a lot in terms of optimizing the software to extend battery life, and sticking with a 1080p display also helps. The Mi 9 does get through a full day of use, but with most smartphones using much larger capacity batteries these days, you'd expect more from Xiaomi.
If you are doing any sort of gaming, or using the phone a lot, then you may not be able to get through a full day. It's worth mentioning that we did use the Mi 9 in the US without a SIM card, since it does not work with US networks. So our battery life is skewed a bit, due to it not working on 4G LTE. But it shouldn't be a huge difference.
Not taking audio seriously
A single down-firing speaker is just not going to cut it for a lot of people these days. Xiaomi is not using the earpiece as a secondary speaker like it has done in the past - likely to keep the bezel and notch smaller. A single speaker doesn't always spell disaster though, but in this case, the Mi 9's single speaker is just not loud enough. It's pretty hard to hear it in a crowded room. On top of that, since it is a down-firing speaker, you also need to cup your hand to make sure that you are not muffling the sound coming out of that single speaker.
To make matters worse, but not surprising, there is also no Dolby Atmos included. More and more phones are adding Dolby Atmos support, making those speakers on the phone even better. But that is not the case with the Mi 9. Now it's also worth noting that smartphones not sold in the US, typically do not have Dolby Atmos included. So it's not a huge surprise for Xiaomi to omit that feature, but it isn't a great reason for it.
The skinny on the audio of the Mi 9 is that the speaker is not great, and there's no headphone jack. The removal of the headphone jack is not new, and has been going on for a few years. What it means is that you're going to want to use a pair of Bluetooth headphones and likely a Bluetooth speaker too.
Securing your smartphone should not be this inconvenient
Unlocking this smartphone is not going to be fun or fast. Mi 9 is using an in-display fingerprint sensor, which is another capacitive sensor. Which means it is not a fast one. This is because it needs to light up the screen to see your finger and then unlock. It is faster than some of the others out there - much faster than the Nokia 9 PureView's sensor - but it's still slower than a capacitive sensor on the back of the phone.
In-display fingerprint sensors are very slowly, but surely getting better. There's still a pretty long way to go, however.
Xiaomi does have facial recognition included, but as we've seen with other Android smartphones, that method is not all that secure. While it is pretty fast, it is very easy to spoof it. You can simply print out a picture and use that to unlock the phone. This isn't just an issue with Xiaomi, it is also an issue with the Galaxy S10 and other smartphones that use facial recognition.
MIUI does indeed have ads. This is somewhat new, but still very annoying. Imagine spending $500 for a brand new smartphone, only to get ads served up to you in apps that were pre-installed on the phone. Not a great experience. Xiaomi has defended this by saying that it allows the company to keep their prices low. But not a single customer has been okay with that reasoning. Many would rather pay a bit more, to get an ad-free experience. Which is also something Amazon found out with its Amazon Prime smartphones.
For the most part, MIUI 10 is a great experience. But as always, with any Android skin, there are some quirks. On top of the ads mentioned above, sometimes when you go to the "Recents" menu, it won't show the app that was just recently opened, it'll show something else. A bit of a puzzling thing, but it is an issue. The camera can sometimes be slow. Not all the time, and not even in the same mode all the time.
NFC is included on the Mi 9, but interestingly enough it does not work with mobile payments like Google Pay. This is even with the Mi 9 on the Global ROM, on the Chinese ROM, it won't work because it isn't available in China. It's a bit strange that it does not work though, with Google Pay. All of the MIUI 10 issues we've highlighted here can be fixed with software updates, so luckily these are things that can be resolved.
A great camera, only in the right conditions
The camera is okay, it's not a great or outstanding camera, just okay. This all depends on how you use the camera (auto vs pro, daylight vs night, etc), but the camera doesn't put out images that are as stunning as you'd expect from a smartphone in 2019. The 40-megapixel main sensor on the Mi 9 is really helpful though, as it doesn't really leave out any details, especially in low-light mode. But it doesn't do much to keep noise out of those dimly-lit shots. And that, does make the shots look a lot worse.
AI is still included in the camera, and it still acts as a glorified "auto" button for your pictures. AI will adjust the exposure, ISO and more to give you the best shot. It's great for those that don't want to mess with the "Pro" mode, but it doesn't seem to be as big of a difference with AI on versus it being off. In previous smartphones from Xiaomi, there was a huge difference. Now, most of the time, you won't even notice a difference between the two. Xiaomi is missing some key things that AI could do in this camera though, including lining up the shot properly, letting you know if someone blinked or looked away, etc. Right now, it's actually rather useless. For the majority of our review, we kept it off, as there was no real reason to actually keep AI on.
Xiaomi has stuck with a pretty familiar design on this smartphone. It has a 2.5D curved glass back, with a big camera bump and an almost all-screen frontside. It's something we've seen from Xiaomi time and time again. But there are some issues with this design, mainly the camera bump. The camera bump is pretty big. And with the phone having that curved backside, it means that it will wobble if you are using it on a table. It also just looks terrible. If you do not use a case with the Mi 9, you are going to get all kinds of dust around that camera, making it almost impossible to wipe it all off and keep the phone looking pristine.
Most if not all consumers would rather companies use a thicker body and make the camera flush with the backside, and add more battery capacity to the phone. Than to have a big camera bump like what is available here. That is something that LG finally figured out with the G8 ThinQ and V50 ThinQ this year, and Xiaomi has not come to that realization yet.
Last but not least, the Mi 9 is not waterproof. It's probably the only smartphone to come out this year without any certification for water-resistance or being water-proof. That is a feature that just about every smartphone in the past few years has had. So it's rather puzzling that Xiaomi does not have that included.
You Get What You Pay For
The Xiaomi Mi 9 is not as expensive as some other smartphones on the market, and you can see why. The camera looks good on paper, but does suffer in low light. The in-display fingerprint sensor is not that great, it also has a small battery capacity, just to name a few things. It's not the perfect smartphone, but that is to be expected. If the perfect smartphone existed, then smartphone makers would never need to make another smartphone.