| Brand: | Vivo |
| Model: | X21 |
| Type: | Smartphone |
| Release Date: | 2018, March |
| Size: | 6.28 inches, 98.4 cm2 (~85.2% screen-to-body ratio) |
| Resolution: | 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) |
| Technology: | Super AMOLED |
| Protection: | Corning Gorilla Glass 3 |
| Main Specs: | 12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF, 5 MP, f/2.4, (depth) |
| Main Features: | LED flash, HDR, panorama |
| Main Video: | 1080p@30fps |
| Selfie Specs: | 12 MP, f/2.0, (wide), 1/2.8", 1.28µm |
| Selfie Video: | 1080p@30fps |
| Capacity: | Li-Ion 3200 mAh, non-removable |
| Type: | Li-Ion |
| Chipset: | Qualcomm SDM660 Snapdragon 660 (14 nm) |
| Ram: | 6GB |
| Storage: | 64GB |
| Expandable: | microSDXC (uses shared SIM slot) |
| Os Version: | 8.1 |
| Dimensions: | 154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in) |
| Weight: | 156.2 g (5.50 oz) |
| Wifi: | Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, hotspot |
| Bluetooth: | 5.0, A2DP, LE |
| Nfc: | No |
| Usb: | microUSB 2.0, USB On-The-Go |
| Headphone Jack: | Yes |
| Network: | GSM / CDMA / HSPA / LTE |
| Sensors: | Fingerprint (rear-mounted), accelerometer, proximity, compass |
| Colors: | Black, Aurora White, Ruby Red |