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Xiaomi Mi 9 review: Waving the flag for the next generation of smartphones

Our Rating :
Price when reviewed : £499
inc VAT

Xiaomi’s Mi 9 is the first smartphone we’ve tested that’s powered by a Snapdragon 855, but is this a worthwhile upgrade?


  • Incredibly well-priced
  • Snapdragon 855 offers significant performance improvements
  • Battery life is superb


  • None whatsoever

With Xiaomi firmly planting its flag on UK shores last year, its arrival has since been met not with a faint whimper, but with thunderous applause. The Chinese smartphone giant has made great strides in the West in little over a year, offering handsets with flagship features at far more palatable prices.

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That trend looks to continue with its latest top-end smartphone, the Xiaomi Mi 9. Unveiled at Xiaomi’s launch event in Barcelona, the Mi 9 is the first Snapdragon 855-equipped smartphone to hit the market, but is this next-generation mobile processor all it’s cracked up to be?

Xiaomi Mi 9 review: What you need to know

Last year’s Mi 8 smartphones were both formidable and well-priced, ultimately placing Xiaomi as a key rival to OnePlus, and the Mi 9 is poised to carry on those successes. Equipped with Qualcomm’s brand-new Snapdragon 855 processor, which promises to deliver substantial performance boosts over last year’s Snapdragon 845, the Mi 9 also includes a rather generous 6GB of RAM and a choice of either 64GB or 128GB of internal storage.

What’s also special is that the Mi 9 is fitted with a fancy 48-megapixel camera which, equalled only by the recently-launched Honor View 20, is the highest resolution smartphone snapper we’ve seen so far. If Xiaomi’s marketing materials are to be believed, we should expect to capture far better quality images and video than we’re currently used to.

Xiaomi Mi 9 review: Price and competition

That all sounds rather good, and we finally know how much Xiaomi’s latest flagship killer will cost when it arrives in the UK. You can pick up the Xiaomi Mi 9 for £499 from 30 April, although it’s exclusively available on Vodafone. 

Buy Xiaomi Mi 9 now from Vodafone

Still, that puts the Mi 9 against a lineup of strong rivals, while simultaneously undercutting the majority of 2019’s upcoming fleet of flagships. The OnePlus 6T is perhaps its biggest adversary, with similar top-end specifications for roughly the same price, as well as a superb rear camera arrangement that beats almost anything else on the market. Likewise, the Honor View 20 is roughly the same price as the Xiaomi Mi 9 while matching its 48-megapixel camera.

Xiaomi Mi 9 review: Design and features

The design of the Mi 9 is similar to its precursor, but Xiaomi has reduced the top notch from a wide-spanning, iPhone-copying, eyesore to a small teardrop that holds the 20-megapixel selfie camera. Screen size is marginally bigger at 6.39in compared to 6.23in, but once again it’s a Super AMOLED panel with an FHD+ resolution. As before, the fingerprint sensor is embedded in the phone’s display, and it’s remarkably speedy at that.

Power and volume buttons are situated on the right edge of the phone, with the USB Type-C charging port and speakers on the bottom. On the left-hand side, you’ll find the SIM slot and a dedicated Google Assistant button, which when pressed serves one (obvious) purpose: to activate Google Assistant. Given that you can already do this using your voice or by tapping and holding the navigation bar, this does seem like an unnecessary addition and, unlike other phones, you also can’t remap this button to launch other apps. There is no headphone jack on the Xiaomi Mi 9 either, which is a shame, but hardly uncommon in smartphones these days.

There are three colour options available: Piano Black, Ocean Blue and an alluring Lavender Violet. The two brighter colours are eye-catching and appear to change colour as they reflect the light around them but, as is the case with most phones that have a glass backing and a lighter colour scheme, the Xiaomi Mi 9 picks up greasy fingerprints all too easily.

Xiaomi Mi 9 review: Display

The Xiaomi Mi 9 follows the trend for tall, thin displays with a slightly-larger 6.39in, 2,340 x 1,080 resolution Super AMOLED screen with an 18:9 aspect ratio. The pixel density of 403ppi makes for ample sharpness, and there’s a tiny circular notch at the top of the screen, along with skinny bezels on both sides and underneath the display.

As for the quality of the screen, this is quite simply the best-looking smartphone display I’ve ever tested. According to our ColorMunki calibrator, the Xiaomi Mi 9’s panel displayed 98.9% of the sRGB colour space on the phone’s “standard” display profile, with an average Delta E of 0.69. A score of less than 1 indicates that colours are displayed perfectly across the entire palette, and the Mi 9 is certainly no exception.

As this is a Super AMOLED panel, the screen also delivers unbeatable contrast levels of infinity:1, while the phone is capable of reaching a maximum brightness of 426cd/m2. In summary, this phone’s screen is a good as they come, delivering rich, vibrant-looking colours that appear to pop right off the screen. If you’re frequently tinkering with your Instagram shots on the go, or you’re seeking the best device for your Netflix binges on the morning commute, there’s simply nothing better.

Xiaomi Mi 9 review: Performance and battery life

Taking centre stage is Qualcomm’s brand new flagship mobile processor, the Snapdragon 855 chipset. This is a new 7nm architecture chip with eight cores, which is configured slightly differently to its predecessor. Instead of two quad-core CPUs; one for high power tasks and one “efficiency”-based CPU less power-intensive tasks, the 855 has an intriguing triple arrangement.

The way this works is that a single “prime core” runs at a clock speed of 2.84GHz, while the “performance CPU” runs at 2.42GHz and the “efficiency CPU” is clocked at 1.8GHz. According to Qualcomm, this enables the Snapdragon 855 to deliver higher levels of sustained performance than any Qualcomm-branded chip before it, as well as beating both Apple’s A12 Bionic and Huawei’s Kirin 980 in high-performance tasks.

Put the Snapdragon 855 to the test and it’s clear that the Mi 9 offers a substantial performance boost over phones with the previous-generation chipset. In the demanding duo of Geekbench 4 single- and multi-core CPU tests, the Snapdragon 855 outperforms the Snapdragon 845 by up to 45%. It also provides faster speeds than both Huawei’s Kirin 980 and even Samsung’s Exynos 9810 equivalent processors, although Qualcomm’s flagship chipset still lags slightly behind Apple’s A12 Bionic chip.

The Snapdragon 855 also benefits from improved graphical capabilities, courtesy of the new embedded Adreno 640 GPU. The Xiaomi Mi 9 reached a perfect score of 60fps in the GFXBench GL Manhattan 3.0 on-screen benchmark and, anecdotally, I never had any issues with dropped frames, even during frenetic shootouts in PUBG: Mobile.

Perhaps most importantly, the Snapdragon 855 is much more power efficient than the Snapdragon 845 it replaces. Being manufactured on a smaller fabrication process clearly has its benefits, as the Mi 9 was capable of reaching 22hrs 54mins on a single charge during our continuous video playback test. For comparison, this means the Mi 9 lasts 46% longer than Xiaomi’s previous phone; a demonstration of serious stamina.

Xiaomi Mi 9 review: Software

As for software, the Xiaomi Mi 9 includes Google’s most recent version of its mobile operating system, Android 9 Pie. This isn’t a stock Android experience, however, and there are a couple of slight tweaks that need to be discussed.

Buy Xiaomi Mi 9 now from Vodafone

That’s because Xiaomi’s own MiUI software overlay is present yet again, which changes the look of Android icons and tweaks the notifications menu. That’s about all there is to it, though, and while it does take a bit of getting used to, this is far from being as intrusive as some of the other Android tweaks on the market.

Xiaomi Mi 9 review: Camera

On to the Xiaomi Mi 9’s triple camera capabilities. Last year’s Mi 8 didn’t benefit from such an arrangement, but ever since the Huawei P20 Pro was first introduced, this seems to be the way premium smartphones are headed. Samsung’s at it too, with its new Galaxy S10 and Galaxy S10 Plus, although Apple has yet to jump on board.

Regardless, the Mi 9’s 48-megapixel (f/1.75) camera unit takes pride of place on the back of the phone, which uses an all-new Sony IMX586 quad-sensor – the very same bit of kit that was used on the Honor View 20. Although the main camera is capable of taking 48-megapixel photos, the Mi 9’s AI function captures a 12-megapixel image by default, and you are unable to shoot with HDR enabled while taking a 48-megapixel shot.

Reinforcing the primary camera is a 16-megapixel (f/2.2) ultrawide module and a 12-megapixel (f/2.2) telephoto camera. Handily, the photo size is listed in the watermark in the bottom left corner when viewing photos in the gallery, so you can see at a glance which shots are 48-megapixel and which are 12-megapixel AI images. This can also be disabled if you wish.

Compare the 48-megapixel images with the shots captured on the OnePlus 6T, and the differences are night and day. There’s a substantial amount more detail in the pictures taken on the Xiaomi Mi 9, even when zoomed right into the image, as you can see from my outdoor test shots. Colours look nice and neutral, and definition is superb. The lack of an HDR mode in the 48-megapixel shooting setting didn’t seem to be too much of a problem, either.

The differences aren’t quite so major as the light dims, however. There’s slightly less visual noise present in the Mi 9’s low-light test shots, but the OnePlus 6T manages to punch up the contrast a little better. On the whole, though, both images look rather similar.

For video, the Mi 9 impresses even more, offering crisp 4K recording at a maximum framerate of 60fps. All of this is fully stabilised of course, and you can even encode the video to H.265 format, reducing file sizes further without any notable impact on image quality. Other recording features include FHD slow-motion capture at 960fps, a night mode which reduces visual noise and brightens up low-light shots, and a portrait mode for Bokeh-like, blurred background photos.

Xiaomi Mi 9 review: Verdict

It’s not often that I review a faultless smartphone. Whether it’s screen woes or a shorter than expected battery life, there’s almost always something that slightly lets a smartphone down. The Mi 9 has nothing of the sort.

The Mi 9’s positives are numerous; its screen is above reproach (even for the most discerning of eyeballs), it outperforms practically every other smartphone currently on the market, and that 48-megapixel camera is a terrific photographer’s companion, too.

Indeed, Xiaomi’s Mi 9 represents the very pinnacle of smartphone technology, and I’m simply astounded that it does things this well, while costing so little in return. The Mi 9 is yet another five-star smartphone from Xiaomi, and It certainly doesn’t get any better than this.

Xiaomi Mi 9 specifications
ProcessorOcta-core 2.84GHz Qualcomm Snapdragon 855 (1×2.84GHz, 3×2.4GHz, 4×1.8GHz)
Screen size6.39in
Screen resolution2,340×1,080
Pixel density403ppi
Screen typeSuper AMOLED
Front camera20-megapixel, f/2.0
Rear camera48-megapixel f/1.8, 16-megapixel f/2.2, 12-megapixel f/2.2
Dust and water resistanceN/A
3.5mm headphone jackNo
Wireless chargingYes
USB connection typeUSB Type-C
Storage options128GB
Memory card slot (supplied)N/A
Cellular data4G
Dual SIMYes
Dimensions (WDH)157 x 75 x 7.6 mm
Operating systemAndroid 9.0
Battery size3,300mAh

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