| Hardware and OS | Coolpad Cool 21 | |
| Operating system | Android v11 | |
| Processor | MediaTek Helio G80 | |
| RAM | 6 GB | |
| Internal Storage | 128 GB | |
| Display | Coolpad Cool 21 | other phones |
| Type | IPS LCD | |
| Size | 6.52 inches | |
| Resolution | 720 x 1600 Pixels | |
| Pixel Density | 269 ppi | |
| Touchscreen | Yes, Capacitive Touchscreen, Multi-touch | |
| Connectivity | Coolpad Cool 21 | other phones |
| Network support | 4G , 3G, 2G | |
| WI-FI | Yes, Wi-Fi 802.11, b/g/n | |
| Gps | Yes, with A-GPS | |
| Bluetooth | Yes, v5.0 | |
| Dual SIM | Dual SIM, GSM GSM | |
| SIM size | SIM1: Nano, SIM2: Nano | |
| USB connectivity | Mass storage device, USB charging | |
| Camera | Coolpad Cool 21 | other phones |
| Main camera | 48 MP 8 MP 2 MP | |
| Front camera | 5 MP | |
| Front camera resolution | 5 MP | |
| Camera features | Digital Zoom, Auto Flash, Face detection, Touch to focus | |
| Flash | Yes, LED Flash | |
| Autofocus | Yes | |
| Video recording | Yes | |
| Multimedia | Coolpad Cool 21 | other phones |
| Audio jack | 3.5 MM | |
| Loudspeaker | Yes | |
| Design | Coolpad Cool 21 | other phones |
| Height | 164.3 mm | |
| Width | 75.66 mm | |
| Thickness | 8.65 mm | |
| Weight | 199.6 grams | |
| Colours | Earl Black, Secret Sea Blue, and Cocoa White | |
| Battery | Coolpad Cool 21 | other phones |
| Capacity | 4500 mAh | |
| Type | Li-Polymer | |
| Other | Coolpad Cool 21 | other phones |
| Fingerprint sensor | Yes | |
| Fingerprint sensor position | Side | |
| Other sensors | Accelerometer, Proximity | |
