Product
Vivo X21 UD
Vivo X21 UD
Vivo X23
Vivo X23
Battery
Charging 18W wired 22.5W wired
Type Li-Ion 3200 mAh, non-removable Li-Ion 3400 mAh, non-removable
Body
Build Glass front (Gorilla Glass 3), aluminum back, aluminum frame -
Dimensions 154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in) 157.7 x 74.1 x 7.5 mm (6.21 x 2.92 x 0.30 in)
SIM Nano-SIM + Nano-SIM Nano-SIM + Nano-SIM
Weight 156.2 g (5.50 oz) 160.5 g (5.68 oz)
Comms
Bluetooth 5.0, A2DP, LE 5.0, A2DP, EDR, LE, aptX
NFC No No
Positioning GPS, GLONASS GPS, GLONASS
Radio FM radio FM radio
USB microUSB 2.0, OTG microUSB 2.0, OTG
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
Display
Protection Corning Gorilla Glass 3 -
Resolution 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) 1080 x 2340 pixels, 19.5:9 ratio (~402 ppi density)
Size 6.28 inches, 98.4 cm2 (~85.2% screen-to-body ratio) 6.41 inches, 100.9 cm2 (~86.3% screen-to-body ratio)
Type Super AMOLED Super AMOLED
Features
Sensors Fingerprint (under display, optical), accelerometer, proximity, compass Fingerprint (under display, optical), accelerometer, proximity, compass
Launch
Announced 2018, March. Released 2018, March 2018, September. Released 2018, September
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 13 MP, f/2.4
Features LED flash, HDR, panorama LED flash, HDR, panorama
Video 1080p@30fps 4K@30fps, 1080p@30fps
Memory
Card slot microSDXC (uses shared SIM slot) No
Internal 128GB 6GB RAM 128GB 8GB RAM
  eMMC 5.1 -
Misc
Colors Black, Ruby Red Phantom Purple, Magic Night, Phantom Red
Models X21UD A V1809A, V1816A, V1809T, V1816T
Network
2G bands GSM 850 / 900 / 1800 / 1900 GSM 850 / 900 / 1800 / 1900
3G bands HSDPA 850 / 900 / 1900 / 2100 HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands 1, 2, 3, 5, 8, 34, 38, 39, 40, 41 1, 2, 3, 4, 5, 8, 34, 38, 39, 40, 41
Speed HSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 300/50 Mbps HSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 300/150 Mbps
Technology GSM / CDMA / HSPA / LTE GSM / CDMA / HSPA / LTE
  CDMA 800 & TD-SCDMA CDMA 800 & TD-SCDMA
Platform
Chipset Qualcomm SDM660 Snapdragon 660 (14 nm) Qualcomm SDM670 Snapdragon 670 (10 nm)
CPU Octa-core (4x2.2 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver) Octa-core (4x2.0 GHz Kryo 360 & 4x1.8 GHz Kryo 360)
GPU Adreno 512 Adreno 615
OS Android 8.1 (Oreo), Funtouch 4 Android 8.1 (Oreo), Funtouch 4.5
Selfie camera
Features - HDR
Single 12 MP, f/2.0, (wide), 1/2.8", 1.28µm 12 MP, f/2.0, (wide), 1/2.8", 1.28µm
Video 1080p@30fps 1080p@30fps
Sound
3.5mm jack Yes Yes
Loudspeaker Yes Yes
  32-bit/192kHz Hi-Res audio 32-bit/192kHz Hi-Res audio