How is OxygenOs better than MIUI

OnePlus 7 (Pro) vs. Xiaomi Mi 9: Upper-class smartphones in comparison


Both OnePlus and Xiaomi are considered value-for-money insider tips in Germany. We compared the current top models OnePlus 7 (Pro) and Xiaomi Mi 9 and show you how the smartphones differ.

When Xiaomi announced the Mi 9 at an almost outrageously low price at MWC 2019, a large part of the technology world was sure to be amazed. The Chinese manufacturer has even undercut the price of the OnePlus 6T, which was already known in the Android upper class for a good price-performance ratio. With the OnePlus 7 series, the Xiaomi competitor is now countering a few months later. You can see which model is the better choice for you in the following comparison test.

Technical data of the OnePlus 7 (Pro) and Xiaomi Mi 9

So that you can get a first overview, you will find a table below with the technical specifications of the three smartphones. Perhaps you can already identify the first differences or similarities.

modelOnePlus 7OnePlus 7 ProXiaomi Mi 9
Display size6.41 inches (AMOLED)6.67 inches (Fluid AMOLED)6.39 inches (AMOLED)
Display resolution2,340 x 1,080 pixels3,120 x 1,440 pixels2,340 x 1,080 pixels
operating systemAndroid 9 (Oxygen OS)Android 9 (Oxygen OS)Android 9 (MIUI)
processorSnapdragon 855Snapdragon 855Snapdragon 855
random access memory6/8 GB6/8/12 GB6 GB
Mass storage128/256 GB, not expandable128/256 GB, not expandable64/128 GB, not expandable
Main camera48 MP Sony IMX 586, f / 1.7, OIS48 MP Sony IMX 586, f / 1.6, OIS48 MP Sony IMX 586, f / 1.75
Secondary camera5 MP depth sensor, f / 2.416 MP wide angle, f / 2.216 MP wide angle, f / 2.2
Tertiary cameraunavailable8 MP telephoto, f / 2.4, OIS, 3x zoom12 MP telephoto, f / 2.2, 2x zoom
Front camera16 MP, f / 2.0 (notch)16 MP, f / 2.0 (pop-up)20 MP, f / 2.0 (notch)
battery pack3,700 mAh4,000 mAh3,300 mAh, wireless charging
miscellaneousNFC, Bluetooth 5.0, WLAN-ac, stereo speakersNFC, Bluetooth 5.0, WLAN-ac, stereo speakersNFC, Bluetooth 5.0, WLAN-ac
Weight182 grams206 grams173 grams
Dimensions158 x 75 x 8 mm163 x 76 x 9 mm157.5 x 75 x 8 mm
Technical data: OnePlus 7 (Pro) and Xiaomi Mi 9

Prices and availability

Xiaomi's price hit appeared in March in two memory versions for 449 and 499 euros. Some retailers now offer it around 20 to 30 euros cheaper. The OnePlus 7 will be released in Germany on June 4th for 559 and 609 euros. For the Pro model, OnePlus charges 709, 759 or 829 euros, depending on the memory size. The latter has been available in stores since May 21.

Experience has shown that OnePlus smartphones are very stable in price, which is why you shouldn't hope for a price reduction in the following months. You will certainly not find the three smartphones in retail, but online retailers such as Amazon and Co. offer the devices in this country. In view of the built-in technology, the three phones are significantly cheaper than competing models such as the Galaxy S10 + or Huawei P30 Pro.

Performance and memory

The processor is a Qualcomm Snapdragon 855, currently the fastest chip on the Android market. Until the OnePlus 7 Pro was released, the Xiaomi Mi 9 was even number 1 in the AnTuTu best list, but has now been replaced by the former. The performance of the smartphones is at the absolute highest level and surpasses many more expensive alternatives.

At least six gigabytes (GB) of RAM are always installed. The OnePlus 7 and 7 Pro also offer eight GB of RAM. The Pro model is even available with twelve GB of RAM. The mass storage of the Xiaomi Mi 9 is either 64 or 128 GB. With OnePlus it is either 128 or 256 GB. The storage space cannot be expanded in any model. In contrast to the Mi 9, the OnePlus 7 series offers much faster UFS 3.0 storage.


The displays of the Mi 9 and OnePlus 7 are relatively the same. These are around 6.4-inch AMOLED panels with a resolution of Full HD +. The front camera is located in a notch that has the shape of a water droplet. With Xiaomi, the display is protected by Gorilla Glass 6, OnePlus relies on Gorilla Glass 5.

The display of the OnePlus 7 Pro is much better in comparison. It measures 6.67 inches and dissolves in QHD +. It is also an almost completely rimless Fluid AMOLED panel with curved sides. It offers a refresh rate of 90 Hertz, other smartphones normally only manage 60 Hertz. The higher refresh rate of the screen means that content is displayed much more smoothly. The operating speed therefore increases subjectively strongly. The following video gives you an impression of the 90 Hertz display of the OnePlus smartphone.

battery pack

The OnePlus 7 Pro offers the largest battery capacity with 4,000 mAh. This is followed by the regular OnePlus 7 with 3,700 mAh. The latter should, however, offer a longer battery life due to the smaller and lower resolution display. While the Pro model can be charged with 30 watts via the Warp Charge charger, the OnePlus 7 has a maximum of 20 watts.

At 3,300 mAh, the Xiaomi Mi 9's battery has the lowest capacity of the three smartphones. An 18 watt charger is included, but the Mi 9 supports up to 27 watts via a USB-C cable. It also supports wireless charging - with the appropriate Qi charger even up to 20 watts. Nevertheless, the battery life is likely to be shorter than that of the OnePlus smartphones.


While the OnePlus 7 still has a dual camera, the OnePlus 7 Pro and Xiaomi Mi 9 each have a triple camera on the back. The 48-megapixel main sensor is identical in all models, but there are slight differences in the aperture and in OnePlus it is optically stabilized. In the normal OnePlus 7, the second sensor is only used to collect depth information.

The second and third cameras on the OnePlus 7 Pro and Mi 9 offer wide-angle and tele optics. The core data of the wide-angle camera are the same, but there are differences with the telephoto camera. In the OnePlus 7 Pro it offers triple optical magnification, in the Mi 9 it is only a double zoom factor. Optical stabilization is only available on the OnePlus mobile phone, but the telephoto camera in the Mi 9 has a higher resolution. Videos can be recorded with the three smartphones in 4K at a maximum of 60 frames per second.

Other differences

The Mi 9 and OnePlus 7 Pro are optionally available in colorful versions with color gradients, but the matte back of the OnePlus 7 Pro in Nebula Blue should be emphasized. In addition, the OnePlus smartphones are resistant to water, but do not have IP certification. Incidentally, the Mi 9 has an infrared transmitter to control televisions.

The Android interfaces used are extremely different. OnePlus relies on simple OxygenOS, on Xiaomi smartphones a much more colorful MIUI is used. Both interfaces offer a wide range of functions and are based on Android 9. An update to Android 10 is guaranteed for all models, but OnePlus is much more punctual when it comes to providing updates. We prefer OxygenOS because it is clearer and faster, but this is ultimately a matter of taste.

Conclusion and reviews

The Xiaomi Mi 9 is undoubtedly the best value for money and supports wireless charging. Apart from the triple camera, battery capacity and Android interface, there are no major differences to the normal OnePlus 7.

However, this does not apply to the Pro model. It is way ahead of the Mi 9, especially in terms of display and battery capacity. The triple camera is also a bit better and it offers significantly more memory and mass storage. You have to decide for yourself whether this is worth the minimum surcharge of around 250 euros. For more information, we therefore recommend reading the reviews embedded below.

This is how netzwelt tests

How does netzwelt test? Instead of showering readers with numbers, we opted for a practical test scheme for the individual tests. We use the devices in the editorial office and in everyday life. We take photos, make phone calls and play with them. The aim is to determine the strengths and weaknesses of the device and to give an assessment of what type of user the smartphone is suitable for. Our rating is made up of five individual ratings ("design and workmanship", "equipment, performance and operation", "voice quality and battery life" and "multimedia").

The overall grade results from the individual grades, but the tester can upgrade or downgrade by one grade. This comes into question, for example, if one of the criteria is particularly outstanding in comparison with other devices. You can find out who we are, how we purchase our test devices and how netzwelt finances itself on our transparency page.

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