| Hardware and OS Realme C21A |
| Operating system: | Android v11 |
| Processor: | MediaTek Helio G35 |
| RAM: | 3 GB |
| Internal Storage: | 32 GB |
| Display Realme C21A |
| Type: | IPS LCD |
| Size: | 6.5 inches |
| Resolution: | 720 x 1600 Pixels |
| Pixel Density: | 270 ppi |
| Touchscreen: | Yes, Capacitive Touchscreen, Multi-touch |
| Connectivity Realme C21A |
| Network support: | 4G , 3G, 2G |
| WI-FI: | Yes, Wi-Fi 802.11, a/ac/b/g/n |
| Gps: | Yes, with A-GPS, Glonass |
| Bluetooth: | Yes, v5.0 |
| Dual SIM: | Dual SIM, GSM GSM |
| SIM size: | SIM1: Nano, SIM2: Nano |
| USB connectivity: | Mass storage device, USB charging |
| Camera Realme C21A |
| Main camera: | 13 MP 2 MP 2 MP |
| Front camera: | 5 MP |
| Front camera resolution: | 5 MP, f/2.2, (wide) |
| Camera features: | Digital Zoom, Auto Flash, Face detection, Touch to focus |
| Flash: | Yes, LED Flash |
| Autofocus: | Yes |
| Video recording: | Yes |
| Multimedia Realme C21A |
| Audio jack: | 3.5 MM |
| Loudspeaker: | Yes |
| Design Realme C21A |
| Height: | 165.2 mm |
| Width: | 76.4 mm |
| Thickness: | 8.9 mm |
| Weight: | 190 grams |
| Colours: | Cross Black, Cross Blue |
| Battery Realme C21A |
| Capacity: | 5000 mAh |
| Type: | Li-Polymer |
| Other Realme C21A |
| Fingerprint sensor: | Yes |
| Fingerprint sensor position: | Rear |
| Other sensors: | Accelerometer, Proximity, Compass |
