Product
Vivo X21i
Vivo X21i
Xiaomi Mi 8 Explorer
Xiaomi Mi 8 Explorer
Battery
Charging 18W wired 18W wired, QC4
Type Li-Ion 3425 mAh, non-removable Li-Po 3000 mAh, non-removable
Body
Build - Glass front (Gorilla Glass 5), glass back, aluminum frame (7000 series)
Dimensions 154.4 x 75 x 7 mm (6.08 x 2.95 x 0.28 in) 154.9 x 74.8 x 7.6 mm (6.10 x 2.94 x 0.30 in)
SIM Nano-SIM + Nano-SIM Nano-SIM + Nano-SIM
Weight 159 g (5.61 oz) 177 g (6.24 oz)
Comms
Bluetooth 5.0, A2DP, LE 5.0, A2DP, LE, aptX HD
NFC No Yes
Positioning GPS, GLONASS GPS (L1+L5), GLONASS (L1), BDS (B1), GALILEO (E1+E5a), QZSS (L1+L5)
Radio FM radio No
USB microUSB 2.0, OTG USB Type-C
WLAN Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, DLNA
Display
Protection - Corning Gorilla Glass 5
Resolution 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) 1080 x 2248 pixels (~402 ppi density)
Size 6.28 inches, 98.4 cm2 (~85.0% screen-to-body ratio) 6.21 inches, 97.1 cm2 (~83.8% screen-to-body ratio)
Type Super AMOLED Super AMOLED, HDR10
Features
Sensors Fingerprint (rear-mounted), accelerometer, proximity, compass Face ID, fingerprint (under display, optical), accelerometer, gyro, proximity, barometer, compass
Launch
Announced 2018, May. Released 2018, May 2018, May. Released 2018, July
Status Discontinued Discontinued
Main Camera
Dual 12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF 5 MP, f/2.4, (depth) 12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF, 4-axis OIS 12 MP, f/2.4, 1/3.4", 1.0µm, AF, 2x optical zoom
Features LED flash, HDR, panorama Dual-LED flash, HDR, panorama
Video 1080p@30fps 4K@60fps, 1080p@30/240fps, 720p@960fps
Memory
Card slot microSDXC (uses shared SIM slot) No
Internal 64GB 6GB RAM, 128GB 4GB RAM 128GB 8GB RAM
  eMMC 5.1 -
Misc
Colors Black, Aurora White, Ruby Red, Night Purple Black (transparent back)
Models X21i A -
Network
2G bands GSM 850 / 900 / 1800 / 1900 GSM 850 / 900 / 1800 / 1900
3G bands HSDPA 850 / 900 / 2100 HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands 1, 3, 4, 5, 8, 38, 39, 40, 41 1, 2, 3, 4, 5, 7, 8, 12, 17, 20, 34, 38, 39, 40, 41
Speed HSPA, LTE HSPA 42.2/5.76 Mbps, LTE (4CA) Cat16 1024/150 Mbps
Technology GSM / CDMA / HSPA / LTE GSM / CDMA / HSPA / LTE
  CDMA 800 & TD-SCDMA CDMA 800 & TD-SCDMA
Platform
Chipset Mediatek MT6771 Helio P60 (12 nm) Qualcomm SDM845 Snapdragon 845 (10 nm)
CPU Octa-core (4x2.0 GHz Cortex-A73 & 4x2.0 GHz Cortex-A53) Octa-core (4x2.8 GHz Kryo 385 Gold & 4x1.8 GHz Kryo 385 Silver)
GPU Mali-G72 MP3 Adreno 630
OS Android 8.1 (Oreo), Funtouch 4 Android 8.1 (Oreo), upgradable to Android 10, MIUI 12
Selfie camera
Single 24 MP, f/2.0, 26mm (wide), 1/2.8", 0.9µm 20 MP, f/2.0, (wide), 1/3", 0.9µm TOF 3D, (depth/biometrics sensor)
Video 1080p@30fps
Sound
3.5mm jack Yes No
Loudspeaker Yes Yes
  32-bit/192kHz Hi-Res audio -