| Price | 0 USD |
| Brand | vivo |
| Model | vivo X21 UD |
| Status | Available. Released 2018, March |
| Release Date | 2018-03 |
| RAM | 6 GB RAM |
| STORAGE | 128 GB |
| Memory Slot | microSD, up to 256 GB |
| Rear Camera | 12 MP, 5 MP |
| Feature | HDR, panorama, LED flash |
| Video Recording | 1080p@30fps |
| Front Camera | 12 MP |
| Front Video Recording | 1080p@30fps |
| Network | 2G/3G/4G |
| USB | microUSB 2.0, USB On-The-Go |
| GPS | Yes, with A-GPS, GLONASS |
| Bluetooth | 5.0, A2DP, LE |
| WLAN | Wi-Fi 802.11 a/b/g/n/ac, dual-band, WiFi Direct, hotspot |
| SIM | Hybrid Dual SIM (Nano-SIM, dual stand-by) |
| EDGE | Yes |
| GPRS | Yes |
| Speed | HSPA 42.2/5.76 Mbps, LTE-A (2CA) Cat6 300/50 Mbps |
| Type | Non-Removable Battery |
| Size | 3200 mAh, Li-Ion Battery |
| Charging | Fast battery charging 18W |
| Sensors | Fingerprint (under display), accelerometer, proximity, compass |
| Type | Super AMOLED capacitive touchscreen, 16M colors |
| Size | 6.28 inches, 1080 x 2280 Pixel |
| Aspect Ratio | 19:9 |
| PPI | ~402 ppi density |
| Screen to Body Ratio | ~85.2% |
| Protection | |
| Build | Front glass, aluminum body |
| OS | Android 8.1 Oreo |
| Chipsets | Qualcomm SDM660 Snapdragon 660 (14 nm) |
| GPU | Adreno 512 |
| CPU | Octa-core (4x2.2 GHz Kryo 260 & 4x1.8 GHz Kryo 260) |
| Colors | Black, Ruby Red |
| Weight | 156.2 g (5.50 oz) |
| Dimensions | 154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in) |
| NFC | |
| 3.5mm Jack | |
| Charging | Fast battery charging 18W |
| Water Proof |
| Radio | FM radio |
| Loudspeaker | Yes |