Product
Vivo X21i
Vivo X21i
Vivo Y400 Pro
Vivo Y400 Pro
Battery
Charging 18W wired 90W wired, 50% in 19 min 6W reverse wired
Type Li-Ion 3425 mAh, non-removable Li-Ion 5500 mAh
Body
Build - Glass front, plastic back, plastic frame
Dimensions 154.4 x 75 x 7 mm (6.08 x 2.95 x 0.28 in) 163.8 x 75.0 x 7.5 or 7.7 mm
SIM Nano-SIM + Nano-SIM Nano-SIM + Nano-SIM
Weight 159 g (5.61 oz) 182 g (6.42 oz)
  - IP65 dust tight and water resistant (low pressure water jets)
Comms
Bluetooth 5.0, A2DP, LE 5.4, A2DP, LE
Infrared port - Yes
NFC No No
Positioning GPS, GLONASS GPS, GLONASS, GALILEO, BDS, QZSS
Radio FM radio No
USB microUSB 2.0, OTG USB Type-C 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
Display
Resolution 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) 1080 x 2392 pixels (~388 ppi density)
Size 6.28 inches, 98.4 cm2 (~85.0% screen-to-body ratio) 6.77 inches, 110.9 cm2 (~90.3% screen-to-body ratio)
Type Super AMOLED AMOLED, 120Hz, HDR, 1300 nits (HBM), 4500 nits (peak)
Features
Sensors Fingerprint (rear-mounted), accelerometer, proximity, compass Fingerprint (under display, optical), accelerometer, gyro, proximity, compass
  - Circle to Search
Launch
Announced 2018, May. Released 2018, May 2025, June 20
Status Discontinued Available. Released 2025, June 27
Main Camera
Dual 12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF 5 MP, f/2.4, (depth) 50 MP, f/1.8, (wide), 1/1.95", 0.8µm, PDAF 2 MP, f/2.4, (depth)
Features LED flash, HDR, panorama Ring-LED flash, panorama, HDR
Video 1080p@30fps 4K@30fps, 1080p@30fps, gyro-EIS
Memory
Card slot microSDXC (uses shared SIM slot) No
Internal 64GB 6GB RAM, 128GB 4GB RAM 128GB 8GB RAM, 256GB 8GB RAM
  eMMC 5.1 UFS 3.1
Misc
Colors Black, Aurora White, Ruby Red, Night Purple Fest Gold, Freestyle White, Nebula Purple
Models X21i A -
SAR - 0.90 W/kg (head)    
SAR EU - 0.85 W/kg (head)    
Network
2G bands GSM 850 / 900 / 1800 / 1900 GSM 850 / 900 / 1800 / 1900
3G bands HSDPA 850 / 900 / 2100 HSDPA 850 / 900 / 2100
4G bands 1, 3, 4, 5, 8, 38, 39, 40, 41 1, 3, 5, 8, 28, 38, 40, 41
5G bands - 1, 3, 5, 8, 28, 38, 40, 41, 77, 78 SA/NSA
Speed HSPA, LTE HSPA, LTE, 5G
Technology GSM / CDMA / HSPA / LTE GSM / HSPA / LTE / 5G
  CDMA 800 & TD-SCDMA -
Platform
Chipset Mediatek MT6771 Helio P60 (12 nm) Mediatek Dimensity 7300 (4 nm)
CPU Octa-core (4x2.0 GHz Cortex-A73 & 4x2.0 GHz Cortex-A53) Octa-core (4x2.5 GHz Cortex-A78 & 4x2.0 GHz Cortex-A55)
GPU Mali-G72 MP3 Mali-G615 MC2
OS Android 8.1 (Oreo), Funtouch 4 Android 15, Funtouch 15
Selfie camera
Single 24 MP, f/2.0, 26mm (wide), 1/2.8", 0.9µm 32 MP, f/2.5, (wide)
Video 4K@30fps, 1080p@30fps
Sound
3.5mm jack Yes No
Loudspeaker Yes Yes, with stereo speakers
  32-bit/192kHz Hi-Res audio 24-bit/192kHz Hi-Res & Hi-Res wireless audio