Product
Xiaomi Mi 4s
Xiaomi Mi 4s
Xiaomi Redmi K20 Pro
Xiaomi Redmi K20 Pro
Battery
Charging 18W wired, QC2, 40% in 60 min 27W wired, QC4
Type Li-Ion 3260 mAh, non-removable Li-Po 4000 mAh, non-removable
Body
Build - Glass front (Gorilla Glass 5), glass back (Gorilla Glass 5), aluminum frame
Dimensions 139.3 x 70.8 x 7.8 mm (5.48 x 2.79 x 0.31 in) 156.7 x 74.3 x 8.8 mm (6.17 x 2.93 x 0.35 in)
SIM Nano-SIM + Micro-SIM Nano-SIM + Nano-SIM
Weight 133 g (4.69 oz) 191 g (6.74 oz)
Comms
Bluetooth 4.1, A2DP 5.0, A2DP, LE, aptX HD
Infrared port Yes -
NFC No Yes (China only)
Positioning GPS, GLONASS, BDS GPS (L1+L5), GLONASS (G1), BDS (B1), GALILEO (E1+E5a)
Radio No Yes
USB USB Type-C USB Type-C 2.0, OTG
WLAN Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, hotspot Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct
Display
Protection - Corning Gorilla Glass 5
Resolution 1080 x 1920 pixels, 16:9 ratio (~441 ppi density) 1080 x 2340 pixels, 19.5:9 ratio (~403 ppi density)
Size 5.0 inches, 68.9 cm2 (~69.9% screen-to-body ratio) 6.39 inches, 100.2 cm2 (~86.1% screen-to-body ratio)
Type IPS LCD Super AMOLED, HDR10
Features
Sensors Fingerprint (rear-mounted), accelerometer, gyro, proximity, compass Fingerprint (under display, optical), accelerometer, gyro, proximity, compass
Launch
Announced 2016, February. Released 2016, March 2019, May 28. Released 2019, June 01
Status Discontinued Discontinued
Main Camera
Features Dual-LED dual-tone flash, panorama, HDR Laser AF, Dual-LED flash, HDR, panorama
Single 13 MP, f/2.0, PDAF -
Triple - 48 MP, f/1.8, 26mm (wide), 1/2.0", 0.8µm, PDAF 8 MP, f/2.4, 53mm (telephoto), 1/4.0", 1.12µm, PDAF, 2x optical zoom 13 MP, f/2.4, 12mm (ultrawide), 1/3.1", 1.12µm
Video 1080p@30fps, 720p@120fps 4K@30/60fps, 1080p@30/120/240fps, 1080p@960fps
Memory
Card slot microSDXC (uses shared SIM slot) No
Internal 64GB 3GB RAM 64GB 6GB RAM, 128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM
  eMMC 5.0 UFS 2.1
Misc
Colors Black, White, Gold, Pink Carbon black, Flame red, Glacier blue, Summer Honey, Pearl White
Models - M1903F11I
SAR - 1.03 W/kg (head)     0.72 W/kg (body)    
Network
2G bands GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2 GSM 850 / 900 / 1800 / 1900
3G bands HSDPA 850 / 1900 / 2100 HSDPA 850 / 900 / 1900 / 2100
4G bands 1, 3, 7, 38, 39, 40, 41 1, 3, 5, 7, 8, 34, 38, 39, 40, 41
Speed HSPA, LTE Cat4 150/50 Mbps HSPA, LTE
Technology GSM / CDMA / HSPA / LTE GSM / HSPA / LTE
  TD-SCDMA -
Our Tests
Audio quality Noise -94.9dB / Crosstalk -82.6dB Noise -93.9dB / Crosstalk -94.2dB
Battery (old) Endurance rating 75h Endurance rating 103h
Camera Photo / Video Photo / Video
Display Contrast ratio: 975:1 (nominal), 2.095 (sunlight) 643 nits max brightness (measured)
Loudspeaker Voice 73dB / Noise 68dB / Ring 82dB Voice 71dB / Noise 75dB / Ring 84dB
Performance Basemark OS II 2.0: 1545Basemark X: 12990 AnTuTu: 368846 (v7), 437823 (v8) GeekBench: 10684 (v4.4), 2732 (v5.1) GFXBench: 36fps (ES 3.1 onscreen)
Platform
Chipset Qualcomm MSM8992 Snapdragon 808 (20 nm) Qualcomm SM8150 Snapdragon 855 (7 nm)
CPU Hexa-core (4x1.4 GHz Cortex-A53 & 2x1.8 GHz Cortex-A57) Octa-core (1x2.84 GHz Kryo 485 & 3x2.42 GHz Kryo 485 & 4x1.78 GHz Kryo 485)
GPU Adreno 418 Adreno 640
OS Android 5.1 (Lollipop), upgradable to 7.0 (Nougat), MIUI 10 Android 9.0 (Pie), upgradable to Android 10, MIUI 12
Selfie camera
Features - HDR
Single 5 MP, f/2.0 Motorized pop-up 20 MP, f/2.2, (wide), 1/3.4", 0.8µm
Video 1080p@30fps 1080p@30fps
Sound
3.5mm jack Yes Yes
Loudspeaker Yes Yes
  - 24-bit/192kHz Hi-Res audio