Product
Vivo X21i
Vivo X21i
Apple iPhone 7
Apple iPhone 7
Battery
Charging 18W wired -
Talk time - Up to 14 h (3G)
Type Li-Ion 3425 mAh, non-removable Li-Ion 1960 mAh, non-removable (7.45 Wh)
Body
Build - Glass front (Corning-made glass), aluminum back, aluminum frame
Dimensions 154.4 x 75 x 7 mm (6.08 x 2.95 x 0.28 in) 138.3 x 67.1 x 7.1 mm (5.44 x 2.64 x 0.28 in)
SIM Nano-SIM + Nano-SIM Nano-SIM
Weight 159 g (5.61 oz) 138 g (4.87 oz)
  - IP67 dust/water resistant (up to 1m for 30 min)Apple Pay (Visa, MasterCard, AMEX certified)
Comms
Bluetooth 5.0, A2DP, LE 4.2, A2DP, LE
NFC No Yes
Positioning GPS, GLONASS GPS, GLONASS, GALILEO, QZSS
Radio FM radio No
USB microUSB 2.0, OTG Lightning, USB 2.0
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, hotspot
Display
Protection - Ion-strengthened glass
Resolution 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) 750 x 1334 pixels, 16:9 ratio (~326 ppi density)
Size 6.28 inches, 98.4 cm2 (~85.0% screen-to-body ratio) 4.7 inches, 60.9 cm2 (~65.6% screen-to-body ratio)
Type Super AMOLED Retina IPS LCD, 625 nits (typ)
  - 3D Touch display & home button
Features
Sensors Fingerprint (rear-mounted), accelerometer, proximity, compass Fingerprint (front-mounted), accelerometer, gyro, proximity, compass, barometer
Launch
Announced 2018, May. Released 2018, May 2016, September 07. Released 2016, September 16
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) -
Features LED flash, HDR, panorama Quad-LED dual-tone flash, HDR
Single - 12 MP, f/1.8, 28mm (wide), 1/3.0", PDAF, OIS
Video 1080p@30fps 4K@30fps, 1080p@30/60/120fps, 720p@240fps
Memory
Card slot microSDXC (uses shared SIM slot) No
Internal 64GB 6GB RAM, 128GB 4GB RAM 32GB 2GB RAM, 128GB 2GB RAM, 256GB 2GB RAM
  eMMC 5.1 NVMe
Misc
Colors Black, Aurora White, Ruby Red, Night Purple Jet Black, Black, Silver, Gold, Rose Gold, Red
Models X21i A A1660, A1778, A1779, A1780, A1853, A1866, iPhone9,1, iPhone9,3
SAR - 1.19 W/kg (head)     1.19 W/kg (body)    
SAR EU - 1.38 W/kg (head)     1.34 W/kg (body)    
Network
2G bands GSM 850 / 900 / 1800 / 1900 GSM 850 / 900 / 1800 / 1900 - A1660, A1778
3G bands HSDPA 850 / 900 / 2100 HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100 - A1660, A1778
4G bands 1, 3, 4, 5, 8, 38, 39, 40, 41 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 27, 28, 29, 30, 38, 39, 40, 41 - A1660, A1778
Speed HSPA, LTE HSPA 42.2/5.76 Mbps, LTE (3CA) Cat9 450/50 Mbps, EV-DO Rev.A 3.1 Mbps
Technology GSM / CDMA / HSPA / LTE GSM / CDMA / HSPA / EVDO / LTE
  CDMA 800 & TD-SCDMA CDMA2000 1xEV-DO & TD-SCDMA - A1660
Platform
Chipset Mediatek MT6771 Helio P60 (12 nm) Apple A10 Fusion (16 nm)
CPU Octa-core (4x2.0 GHz Cortex-A73 & 4x2.0 GHz Cortex-A53) Quad-core 2.34 GHz (2x Hurricane + 2x Zephyr)
GPU Mali-G72 MP3 PowerVR Series7XT Plus (six-core graphics)
OS Android 8.1 (Oreo), Funtouch 4 iOS 10.0.1, upgradable to iOS 15.8.4
Selfie camera
Features - Face detection, HDR, panorama
Single 24 MP, f/2.0, 26mm (wide), 1/2.8", 0.9µm 7 MP, f/2.2, 32mm (standard)
Video 1080p@30fps
Sound
3.5mm jack Yes No
Loudspeaker Yes Yes, with stereo speakers
  32-bit/192kHz Hi-Res audio -
Tests
Audio quality - Noise -92.4dB / Crosstalk -80.9dB
Battery (old) - Endurance rating 61h
Camera - Photo / Video
Display - Contrast ratio: 1603:1 (nominal), 3.964 (sunlight)
Loudspeaker - Voice 67dB / Noise 73dB / Ring 75dB
Performance - Basemark OS II 2.0: 3416