| Brand | Realme |
| Model | C21Y |
| Device Type | SmartPhone |
| Release Date | 02 July 2021 |
| Status | Available |
| Operating System | Android |
| OS Version | v10 |
| User Interface | Realme UI |
| Chipset | Unisoc T610 |
| CPU | Octa core (1.8 GHz, Dual core, Cortex A75 + 1.8 GHz, Hexa Core, Cortex A55) |
| CPU Cores | 8 Cores |
| Architecture | 64 bit |
| Fabrication | 12 nm |
| GPU | Mali-G52 |
| Display Type | IPS LCD |
| Screen Size | 6.5 inches (16.51 cm) |
| Resolution | 720x1600 px (HD+) |
| Aspect Ratio | 20:9 |
| Pixel Density | 270 ppi |
| Screen to Body Ratio | 81.59 % |
| Screen Protection | Gorilla Glass |
| Bezel-less Display | Yes with waterdrop notch |
| Touch Screen | Capacitive Touchscreen, Multi-touch |
| Brightness | 420 nits |
| Refresh Rate | 60 Hz |
| Notch | Waterdrop |
| Camera Setup | Triple |
| Resolution | 13 MP, f/2.2, Wide Angle (80° field-of-view), Primary Camera, 2 MP, f/2.4, Macro Camera, 2 MP, f/2.4 |
| Sensor | CMOS image sensor |
| Autofocus | Phase Detection autofocus |
| Flash | LED Flash |
| Image Resolution | 4128 x 3096 Pixels |
| Settings | Exposure compensation, ISO control |
| Zoom | 4 x Digital Zoom |
| Shooting Modes | Continuous Shooting, High Dynamic Range mode (HDR) |
| Aperture | f/2.4 |
| Camera Features | Auto Flash, Face detection, Touch to focus |
| Video Recording | 1920x1080 |
| Video FPS | 30 fps |
| Camera Setup | Single |
| Resolution | 5 MP, f/2.2, Wide Angle, Primary Camera |
| Sensor | CMOS |
| Camera Features | Fixed Focus |
| Video Recording | 1280x720 |
| Video FPS | 30 fps |
| Aperture | f/2.2 |
| Height | 164.5 mm |
| Width | 76 mm |
| Thickness | 9.1 mm |
| Weight | 200 grams |
| Build | Glass front, plastic back, plastic frame |
| Colors | Cross Blue, Cross Black |
| Battery type | Li-Ion (Lithium Ion) |
| Capacity | 5000 mAh |
| Reverse Charging | Yes |
| Placement | Non-removable |
| Internal Storage | 32 GB |
| Storage Type | eMMC 5.1 |
| Expandable Memory | Up to 256 GB |
| USB OTG | Yes |
| RAM | 3 GB |
| RAM Type | LPDDR4X |
| Network | 2G, 3G, 4G |
| SIM Slot | Dual SIM, GSM+GSM |
| SIM Size | SIM1: Nano, SIM2: Nano |
| EDGE | Available |
| GPRS | Available |
| VoLTE | Yes |
| Speed | HSPA, LTE |
| SAR Value | Head: 0.855 W/kg, Body: 0.674 W/kg |
| WLAN | Wi-Fi 4 (802.11 b/g/n) |
| Bluetooth | v5.0 |
| GPS | Yes with A-GPS, Glonass |
| Wi-fi Hotspot | Yes |
| USB | Mass storage device, USB charging, microUSB 2.0 |
| Light Sensor | Light sensor, Proximity sensor, Accelerometer, Compass, Gyroscope |
| Fingerprint Sensor | Yes |
| Finger Sensor Position | Rear-mounted |
| Face Unlock | Yes |
| Loudspeaker | Yes |
| Alert Types | Vibration, MP3, WAV ringtones |
| Audio Jack | 3.5 mm |
| Video | 1080p@30fps |
| Document Reader | Yes |
| Made By | China |
| Features | Accelerometer, proximity, compass |
