Xiaomi Mix 4 vs OnePlus 9 Pro: A Deep Dive into Flagship Features

The Xiaomi Mix 4 and OnePlus 9 Pro represent distinct approaches to the flagship Android experience. The Mix 4 pushes boundaries with its under-display camera and blazing-fast charging, while the OnePlus 9 Pro focuses on a refined software experience and Hasselblad-tuned camera system. This comparison dissects their core components to determine which device delivers the most value.
Phones Images

🏆 Quick Verdict

For users prioritizing charging speed and a truly innovative display, the Xiaomi Mix 4 is the clear winner. However, the OnePlus 9 Pro offers a more polished software experience and a consistently excellent camera, making it ideal for photography enthusiasts.

PHONES
Phone Names Xiaomi Mix 4 OnePlus 9 Pro
Network
2G bandsGSM 850 / 900 / 1800 / 1900GSM 850 / 900 / 1800 / 1900
3G bandsHSDPA 850 / 900 / 1700(AWS) / 1900 / 2100HSDPA 800 / 850 / 900 / 1700(AWS) / 1800 / 1900 / 2100
4G bands1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 34, 38, 39, 40, 41, 421, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 28, 32, 38, 39, 40, 41, 66 - EU
5G bands1, 3, 5, 8, 28, 41, 77, 78, 79 SA/NSA/Sub61, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 78 SA/NSA - EU
SpeedHSPA, LTE, 5GHSPA 42.2/5.76 Mbps, LTE Cat20 2000/200 Mbps, 5G
TechnologyGSM / CDMA / HSPA / EVDO / LTE / 5GGSM / CDMA / HSPA / LTE / 5G
 CDMA2000 1xEV-DO 1, 3, 28, 41, 78, 79 SA/NSA - CN
Launch
Announced2021, August 102021, March 23
StatusAvailable. Released 2021, August 16Available. Released 2021, March 30
Body
BuildGlass front (Gorilla Glass Victus), ceramic back, aluminum frameGlass front (Gorilla Glass 5), glass back (Gorilla Glass 5), aluminum frame
Dimensions162.6 x 75.4 x 8 mm (6.40 x 2.97 x 0.31 in)163.2 x 73.6 x 8.7 mm (6.43 x 2.90 x 0.34 in)
SIMNano-SIM + Nano-SIM· Nano-SIM· Nano-SIM + Nano-SIM
Weight225 g (7.94 oz)197 g (6.95 oz)
 IP53, dust and splash resistantIP68 dust/water resistant (up to 1.5m for 30 min)
Display
ProtectionCorning Gorilla Glass VictusCorning Gorilla Glass 5
Resolution1080 x 2400 pixels, 20:9 ratio (~395 ppi density)1440 x 3216 pixels, 20:9 ratio (~525 ppi density)
Size6.67 inches, 107.4 cm2 (~87.6% screen-to-body ratio)6.7 inches, 108.4 cm2 (~90.3% screen-to-body ratio)
TypeAMOLED, 1B colors, 120Hz, HDR10+, Dolby Vision, 800 nits (HBM)LTPO Fluid2 AMOLED, 1B colors, 120Hz, HDR10+, 1300 nits (peak)
 -Always-on display
Platform
CPUOcta-core (1x2.99 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55)Octa-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55
ChipsetQualcomm SM8350 Snapdragon 888+ 5G (5 nm)Qualcomm SM8350 Snapdragon 888 5G (5 nm)
GPUAdreno 660Adreno 660
OSAndroid 11, MIUI 12.5Android 11, upgradable to Android 14, OxygenOS 14
Memory
Card slotNoNo
Internal128GB 8GB RAM, 256GB 8GB RAM, 256GB 12GB RAM, 512GB 12GB RAM128GB 8GB RAM, 256GB 8GB RAM, 256GB 12GB RAM
 UFS 3.1UFS 3.1
Main Camera
FeaturesLaser AF, color spectrum sensor, Dual-LED flash, HDR, panoramaLaser AF, color spectrum sensor, Hasselblad Color Calibration, dual-LED flash, HDR, panorama
Quad-48 MP, f/1.8, 23mm (wide), 1/1.43", 1.12µm, multi-directional PDAF, OIS 8 MP, f/2.4, 77mm (telephoto), 1.0µm, PDAF, OIS, 3.3x optical zoom 50 MP, f/2.2, 14mm (ultrawide), 1/1.56", 1.0µm, AF 2 MP, f/2.4, (monochrome)
Single20 MP, 27mm (wide), 1/3.4", 0.8µm, under display16 MP, f/2.4, (wide), 1/3.06", 1.0µm
Triple108 MP, f/1.9, 24mm (wide), 1/1.33", 0.8µm, PDAF, OIS 8 MP, f/4.1, 120mm (periscope telephoto), PDAF, OIS, 5x optical zoom 13 MP, f/2.2, 12mm, 123˚ (ultrawide), 1/3.06", 1.12µm-
Video8K@24fps, 4K@30/60fps, 1080p@30/60/120/480fps; gyro-EIS, HDR10+8K@30fps, 4K@30/60/120fps, 1080p@30/60/240fps, Auto HDR, gyro-EIS
Selfie camera
FeaturesHDRHDR
Single20 MP, 27mm (wide), 1/3.4", 0.8µm, under display16 MP, f/2.4, (wide), 1/3.06", 1.0µm
Video1080p@30fps1080p@30fps, gyro-EIS
Sound
3.5mm jack NoNo
35mm jackNoNo
Loudspeaker Yes, with stereo speakersYes, with stereo speakers
 24-bit/192kHz audio Tuned by Harman Kardon24-bit/192kHz audio
Comms
Bluetooth5.2, A2DP, LE, aptX HD5.2, A2DP, LE, aptX HD
Infrared portYes-
NFCYesYes
PositioningGPS (L1+L5), GLONASS (G1), BDS (B1I+B1c+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5)GPS (L1+L5), GLONASS (G1), BDS (B1), GALILEO (E1+E5a)
RadioNoNo
USBUSB Type-C 2.0USB Type-C 3.1, OTG
WLANWi-Fi 802.11 a/b/g/n/ac/6e, dual-band, Wi-Fi DirectWi-Fi 802.11 a/b/g/n/ac/6, dual-band, Wi-Fi Direct, DLNA
Features
SensorsFingerprint (under display, optical), accelerometer, gyro, proximity, compassFingerprint (under display, optical), accelerometer, gyro, proximity, compass
 Ultra Wideband (UWB) support-
Battery
Charging120W wired, PD3.0, QC4, 100% in 15 min 50W wireless, 100% in 28 min65W wired, PD, 100% in 29 min 50W wireless, 100% in 43 min 5W reverse wireless
TypeLi-Po 4500 mAhLi-Po 4500 mAh
Misc
ColorsCeramic Black, Ceramic White, Shadow GrayMorning Mist, Forest Green, Stellar Black
Models2106118CLE2121, LE2125, LE2123, LE2120, LE2127
PriceAbout 660 EUR€ 246.17 / $ 264.95 / £ 287.00
Tests
Battery life- Endurance rating 86h
Camera- Photo / Video
Loudspeaker- -24.1 LUFS (Very good)

Xiaomi Mix 4

  • Blazing-fast 120W wired charging
  • Innovative under-display camera
  • Slightly faster processor (Snapdragon 888+)

  • Software experience may be less refined
  • Camera details are currently limited

OnePlus 9 Pro

  • Hasselblad-tuned camera system
  • Polished and stable software experience
  • Excellent display brightness and color accuracy

  • Slower charging speeds
  • Standard camera cutout (notch or punch-hole)

Display Comparison

The OnePlus 9 Pro boasts a measured peak brightness of 859 nits, providing excellent visibility outdoors. However, the Xiaomi Mix 4, while lacking specific brightness data, is expected to be competitive. The key differentiator lies in the Mix 4’s under-display camera, eliminating the notch or punch-hole. Both devices likely utilize LTPO displays for adaptive refresh rates, conserving battery life. The absence of detailed color accuracy data for the Mix 4 makes a direct comparison difficult, but OnePlus’s display is known for its color calibration.

Camera Comparison

The OnePlus 9 Pro’s camera system, co-developed with Hasselblad, is a significant strength. While specific sensor details are missing for the Mix 4, the OnePlus 9 Pro’s focus on color accuracy and dynamic range is well-documented. Both phones offer photo and video capabilities, but the OnePlus 9 Pro’s Hasselblad tuning provides a distinct advantage in image processing. The absence of detailed camera specs for the Mix 4 makes a direct sensor size comparison impossible, but the OnePlus 9 Pro’s system is known for its versatility and consistent performance.

Performance

Both phones are powered by the Qualcomm Snapdragon 888 series, but the Mix 4 features the 888+ variant. The 888+ boasts a slightly higher peak CPU clock speed (2.99 GHz Cortex-X1 vs 2.84 GHz on the 9 Pro), potentially offering a marginal performance boost in CPU-intensive tasks. Both utilize the same CPU core configuration (1x Cortex-X1, 3x Cortex-A78, 4x Cortex-A55). While both use 5nm fabrication, the 888+’s refinements may lead to slightly better thermal management. Both devices likely employ LPDDR5 RAM, but the Mix 4’s faster processor could benefit from faster RAM speeds if implemented.

Battery Life

Both phones offer 50W wireless charging, but the Mix 4 dramatically outpaces the 9 Pro with 120W wired charging, achieving a full charge in just 15 minutes compared to the 9 Pro’s 29 minutes. The OnePlus 9 Pro has an endurance rating of 86h, suggesting good battery optimization. The Mix 4’s faster charging partially mitigates any potential capacity disadvantage, allowing for quick top-ups throughout the day. The Mix 4’s 50W wireless charging (28 minutes to full) is also faster than the OnePlus 9 Pro’s (43 minutes).

Buying Guide

Buy the Xiaomi Mix 4 if you need the absolute fastest charging available, are intrigued by the under-display camera technology, and prioritize raw speed. Buy the OnePlus 9 Pro if you prefer a more refined and stable software experience, value Hasselblad's color science in photography, and appreciate a proven track record of consistent performance.

Frequently Asked Questions

❓ How does the under-display camera on the Xiaomi Mix 4 affect image quality compared to traditional front cameras?
Under-display camera technology inherently involves compromises. Light has to pass through the display pixels, potentially reducing sharpness and contrast. While Xiaomi has made significant strides in minimizing these effects, the Mix 4’s front camera is unlikely to match the quality of the OnePlus 9 Pro’s dedicated front-facing sensor in challenging lighting conditions.
❓ Does the Snapdragon 888+ in the Xiaomi Mix 4 noticeably outperform the Snapdragon 888 in the OnePlus 9 Pro during gaming?
The performance difference between the Snapdragon 888 and 888+ is incremental. While the Mix 4 may exhibit slightly higher frame rates in some demanding games, the difference is unlikely to be substantial. Both phones are capable of handling most mobile games at high settings. Thermal management will be a more significant factor in sustained gaming performance.
❓ Is the 120W charging on the Xiaomi Mix 4 safe for long-term battery health?
Xiaomi incorporates multiple safety mechanisms to mitigate the potential impact of ultra-fast charging on battery health. These include optimized charging algorithms and temperature control. However, consistently using the fastest charging speeds *may* contribute to slightly faster battery degradation over the long term compared to slower charging methods.