Product
Vivo X21
Vivo X21
Samsung Galaxy F55
Samsung Galaxy F55
Battery
Charging 18W wired 45W wired
Type Li-Ion 3200 mAh, non-removable 5000 mAh
Body
Build Glass front (Gorilla Glass 3), aluminum back, aluminum frame Glass front, silicone polymer (eco leather) back, plastic frame
Dimensions 154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in) 163.9 x 76.5 x 7.8 mm (6.45 x 3.01 x 0.31 in)
SIM Nano-SIM + Nano-SIM Nano-SIM + Nano-SIM
Weight 156.2 g (5.50 oz) 180 g (6.35 oz)
Comms
Bluetooth 5.0, A2DP, LE 5.2, A2DP, LE
NFC No Yes
Positioning GPS, GLONASS GPS, GALILEO, GLONASS, 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/6, dual-band, Wi-Fi Direct
Display
Protection Corning Gorilla Glass 3 -
Resolution 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) 1080 x 2400 pixels, 20:9 ratio (~393 ppi density)
Size 6.28 inches, 98.4 cm2 (~85.2% screen-to-body ratio) 6.7 inches, 108.4 cm2 (~86.4% screen-to-body ratio)
Type Super AMOLED Super AMOLED+, 120Hz, 1000 nits (HBM)
Features
Sensors Fingerprint (rear-mounted), accelerometer, proximity, compass Fingerprint (under display, optical), accelerometer, gyro, proximity, compass
Launch
Announced 2018, March. Released 2018, March 2024, May 17
Status Discontinued Available. Released 2024, May 27
Main Camera
Dual 12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF 5 MP, f/2.4, (depth) -
Features LED flash, HDR, panorama LED flash, panorama, HDR
Triple - 50 MP, f/1.8, (wide), 1/1.56", 1.0µm, PDAF, OIS 8 MP, f/2.2, 123˚ (ultrawide) 2 MP, f/2.4, (macro)
Video 1080p@30fps 4K@30fps, 1080p@30/60fps, gyro-EIS, OIS
Memory
Card slot microSDXC (uses shared SIM slot) microSDXC (uses shared SIM slot)
Internal 64GB 6GB RAM, 128GB 6GB RAM 128GB 8GB RAM, 256GB 8GB RAM, 256GB 12GB RAM
  eMMC 5.1 -
Misc
Colors Black, Aurora White, Ruby Red Black, Apricot
Models 1725, X21A SM-E556B/DS, SM-E556B
SAR - 0.93 W/kg (head)    
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, 7, 8, 12, 17, 20, 25, 26, 28, 38, 40, 41, 66
5G bands - 1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78 SA/NSA/Sub6
Speed HSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 300/50 Mbps HSPA, LTE, 5G
Technology GSM / CDMA / HSPA / LTE GSM / HSPA / LTE / 5G
  CDMA 800 & TD-SCDMA -
Platform
Chipset Qualcomm SDM660 Snapdragon 660 (14 nm) Qualcomm SM7450-AB Snapdragon 7 Gen 1 (4 nm)
CPU Octa-core (4x2.2 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver) Octa-core (1x2.4 GHz Cortex-A710 & 3x2.36 GHz Cortex-A710 & 4x1.8 GHz Cortex-A510)
GPU Adreno 512 Adreno 644
OS Android 8.1 (Oreo), Funtouch 4 Android 14, upgradable to Android 15, One UI 7
Selfie camera
Single 12 MP, f/2.0, (wide), 1/2.8", 1.28µm 50 MP, f/2.4, (wide)
Video 1080p@30fps 4K@30fps, 1080p@30/60fps
Sound
3.5mm jack Yes No
Loudspeaker Yes Yes, with stereo speakers
  32-bit/192kHz Hi-Res audio -