| key specs | 
| Display | 6.39-inch | 6.21-inch | 
| Processor | Qualcomm Snapdragon 855 | Qualcomm Snapdragon 845 | 
| Front Camera | 20-megapixel  | 20-megapixel  | 
| Rear Camera | 48-megapixel + 12-megapixel + 16-megapixel  | 12-megapixel + 12-megapixel  | 
| RAM | 6GB | 6GB | 
| Storage | 128GB | 64GB | 
| Battery Capacity | 3300mAh | 3400mAh | 
| OS | Android 9.0 | Android Oreo | 
| Resolution | 1080x2340 pixels | 1080x2248 pixels | 
| general | 
| Brand | Xiaomi | Xiaomi | 
| Model | Mi 9 | Mi 8 | 
| Release date | February 1, 2019 | May 1, 2018 | 
| Form factor | Touchscreen | Touchscreen | 
| Dimensions (mm) | 157.50 x 74.67 x 7.61 | 154.90 x 74.80 x 7.60 | 
| Weight (g) | 173.00 | 175.00 | 
| Battery capacity (mAh) | 3300 | 3400 | 
| Fast charging | Proprietary | - | 
| Wireless charging | Yes | - | 
| Colours | Deep Grey, Holographic Illusion Blue, Holographic Illusion | White, Gold, Light Blue, Black | 
| display | 
| Screen size (inches) | 6.39 | 6.21 | 
| Touchscreen | Yes | Yes | 
| Resolution | 1080x2340 pixels | 1080x2248 pixels | 
| Protection type | Gorilla Glass | - | 
| Aspect ratio | 19.5:9 | 18.7:9 | 
| Pixels per inch (PPI) | - | 402 | 
| hardware | 
| Processor | 2.84GHz octa-core | octa-core (4x2.8GHz + 4x1.8GHz) | 
| Processor make | Qualcomm Snapdragon 855 | Qualcomm Snapdragon 845 | 
| RAM | 6GB | 6GB | 
| Internal storage | 128GB | 64GB | 
| camera | 
| Rear camera | 48-megapixel (f/1.75, 0.8-micron) + 12-megapixel (f/2.2, 1.0-micron) + 16-megapixel (f/2.2, 1.0-micron) | 12-megapixel (f/1.8, 1.4-micron) + 12-megapixel (f/2.4, 1.0-micron) | 
| Rear autofocus | Yes | Phase detection autofocus | 
| Rear flash | Yes | Dual LED | 
| Front camera | 20-megapixel (f/2.0, 0.9-micron) | 20-megapixel (f/2.0, 0.9-micron) | 
| software | 
| Operating system | Android 9.0 | Android Oreo | 
| Skin | MIUI 10 | MIUI 10 | 
| connectivity | 
| Wi-Fi | Yes | Yes | 
| Wi-Fi standards supported | 802.11 a/b/g/n/ac | 802.11 a/b/g/n/ac | 
| GPS | Yes | Yes | 
| Bluetooth | Yes, v 5.00 | Yes, v 5.00 | 
| NFC | Yes | Yes | 
| USB Type-C | Yes | Yes | 
| Number of SIMs | 2 | 2 | 
| USB OTG | - | Yes | 
| sim 1 | 
| SIM Type | Nano-SIM | Nano-SIM | 
| GSM/CDMA | GSM | GSM | 
| 3G | Yes | Yes | 
| 4G/ LTE | Yes | Yes | 
| sim 2 | 
| SIM Type | Nano-SIM | Nano-SIM | 
| GSM/CDMA | GSM | GSM | 
| 3G | Yes | Yes | 
| 4G/ LTE | Yes | Yes | 
| sensors | 
| Face unlock | Yes | Yes | 
| 3D face recognition | Yes | - | 
| Fingerprint sensor | Yes | Yes | 
| Compass/ Magnetometer | Yes | Yes | 
| Proximity sensor | Yes | Yes | 
| Accelerometer | Yes | Yes | 
| Ambient light sensor | Yes | Yes | 
| Gyroscope | Yes | Yes | 
| Barometer | - | Yes |