Xiaomi Redmi K20 Pro/Mi 9T Pro review

GSMArena team, 26 Aug 2019.

Display

The Redmi K20 Pro packs a 6.39" Horizon AMOLED, also called Super AMOLED, meaning Samsung makes it. It is not disturbed by a notch, and the only things eating some pixels are its rounded corners. The resolution of the panel is very common - 2,340 x 1,080 pixels (403ppi) - meaning a 19.5:9 screen aspect ratio.

Xiaomi Redmi K20 Pro/Mi 9T Pro review

The 6.39" 1080p+ AMOLED has become the most common screen on the market nowadays, notch or no notch. They all have a Diamond PenTile subpixel arrangement on their pixel matrix, and the K20 Pro screen is no different.

The K20 Pro OLED supports HDR10 content and fully covers the DCI-P3 color space. It is protected by a Gorilla Glass 5.

The screen has an excellent brightness for an OLED panel of 450 nits - that's in line with what Xiaomi promises (430 nits). But it can go as high as 643 nits in bright light if you leave it on Auto, also matching and even exceeding Xiaomi's official promise for 600 nits.

The minimum brightness when displaying purely white color was 2.2nits - pretty impressive.

Display test 100% brightness
Black, cd/m2 White, cd/m2 Contrast ratio
Xiaomi K20 Pro/Mi 9T Pro 0 453
Xiaomi K20 Pro/Mi 9T Pro (Max Auto) 0 643
Xiaomi Mi 9T 0 449
Xiaomi Mi 9T (Max Auto) 0 646
Xiaomi Mi 9 SE 0 444
Xiaomi Mi 9 SE (Max Auto) 0 637
OnePlus 7 0 443
OnePlus 7 (Max Auto) 0 642
Lenovo Z6 Pro 0 450
Nokia 9 PureView 0 531
Asus Zenfone 6 ZS630KL 0.353 424 1201
Asus Zenfone 6 ZS630KL (Max Auto) 0.399 455 1140
Samsung Galaxy S10e 0 389
Samsung Galaxy S10e (Max Auto) 0 803
Realme X 0 448

Xiaomi offers three different Contrast settings, each one representing a specific color space. The Automatic contrast fully covers the DCI-P3 color space, and we measured an average deltaE of 3.8. Only in this mode, you can choose the color saturation (default, warm, cool) and the deltaE of 3.8, which we measured was taken at the default preset. Choosing Warm will offer an even more accurate presentation with an average deltaE of 2.5.

The Standard Contrast corresponds to sRGB, and we also recorded an average deltaE of 2.4 for the color accuracy, meaning it's a pretty great one.

Finally, the Increased Contrast makes the colors pop and they are no longer as accurate.

Battery life

The Xiaomi Redmi K20 Pro is powered by a 4,000mAh Li-ion battery. It supports Quick Charge, and the supplied 18W charger fills about 50% of a depleted battery in 30 mins. A full charge takes about 100 mins. We tried charging the phone with Xiaomi's 27W charger we had lying around, but it did not charge the battery faster than the supplied one.

The Redmi K20 Pro scored an excellent endurance rating of 103 hours and had great times across the board. The screen-on times are fantastic - we measured 13 and a half hours runtime in our web browsing test and north of 20 hours in our video playback test.

The standby performance was better on the Mi 9T/K20 when compared to the Pro model here, probably meaning its Snapdragon 855 modem is less power efficient in standby than the K20's S730.

Xiaomi Redmi K20 Pro/Mi 9T Pro review

Our battery tests were automated thanks to SmartViser, using its viSerDevice app. The endurance rating above denotes how long a single battery charge will last you if you use the Xiaomi Redmi K20 Pro for an hour each of telephony, web browsing, and video playback daily. We've established this usage pattern so that our battery results are comparable across devices in the most common day-to-day tasks. The battery testing procedure is described in detail in case you're interested in the nitty-gritty. You can check out our complete battery test table, where you can see how all of the smartphones we've tested will compare under your own typical use.

Speaker

There's a single bottom-firing loudspeaker on the Redmi K20 Pro. It is quite loud and scored an Excellent mark on our test. The output is also very good - there is rich sound, but there are some high-pitched notes that come out wrong at maximum volume, and this keeps us from giving it an excellent mark for quality of output.

Speakerphone testVoice, dB Pink noise/ Music, dB Ringing phone, dB Overall score
Realme X 67.9 73.5 80.4 Very Good
OnePlus 7 68.1 73.1 82.2 Very Good
Samsung Galaxy S10e (Dolby Atmos) 70.0 73.9 80.4 Very Good
Xiaomi Mi 9T 70.6 74.8 81.2 Very Good
Samsung Galaxy S10e 71.2 76.8 80.6 Excellent
Xiaomi Redmi K20 Pro 71.5 75.2 84.0 Excellent
Lenovo Z6 Pro 66.4 74.3 90.8 Excellent
Asus Zenfone 6 77.0 75.9 81.2 Excellent
OnePlus 7 Pro 79.6 77.7 87.2 Excellent
Xiaomi Mi 9 SE 86.2 79.0 87.0 Excellent

Audio quality

The Xiaomi Mi 9T Pro did well with an active external amplifier. With super high volume and top marks for clarity, it properly aced the first part of the test.

Headphones dropped the volume a bit, but the Mi 9T Pro remained louder than most smartphones out there. The accuracy of the reproduction took a much bigger hit with stereo crosstalk and intermodulation distortion worsening significantly and frequency response going a little shaky. So while the Mi 9T Pro does have the power to drive high impedance headphones to significant levels of loudness, it won’t necessarily be the best experience.

TestFrequency responseNoise levelDynamic rangeTHDIMD + NoiseStereo crosstalk
Xiaomi Mi 9T Pro+0.03, -0.03-93.993.90.00150.0065-94.2
Xiaomi Mi 9T Pro (headphones)+0.60, -0.03-92.792.90.0210.446-49.1
Xiaomi Mi 9T+0.02, -0.01-93.593.90.00250.0068-93.8
Xiaomi Mi 9T (headphones)+0.60, -0.04-92.993.20.0200.454-49.4
Honor 20+0.02, -0.05-96.396.20.00160.0070-52.1
Honor 20 (headphones)+0.22, -0.21-97.796.30.00490.223-64.7
Honor 20 Pro+0.14, -0.31-92.992.90.4760.574-46.8
Honor 20 Pro (headphones)+0.14, -0.24-88.788.10.00530.223-53.6
Xiaomi Mi 9+0.02, -0.01-93.993.10.00150.0066-91.9
Xiaomi Mi 9 (headphones)+0.05, -0.04-92.693.50.00260.072-58.7
Asus Zenfone 6+0.03, -0.01-85.886.80.00120.014-76.2
Asus Zenfone 6 (headphones)+0.05, -0.01-81.182.70.00680.059-52.0

Xiaomi Mi 9T Pro frequency response
Xiaomi Mi 9T Pro frequency response

You can learn more about the tested parameters and the whole testing process here.

Reader comments

A Youtuber named Marques Brownlee had the similar issue: youtu.be/WpPw7lUXyI0?t=315 Some viewers suggested that his phone might be a faulty one.

  • Anonymous

it is one of the worst but you can not expect everything within 350 usd

  • Vickey

I am not satisfied with this phone. Might I have received faulty one, but the camera quality specially front is worst. if anyone looking for better camera quality so choose another one..