| Hardware and OS | Itel S21 | |
| Operating System | Android v7.0 (Nougat) | |
| Processor | Quad core, 1.1 GHz, Cortex A7 | |
| Chipset | MediaTek MT6580M | |
| Architecture | 32 bit | |
| RAM | 1 GB | |
| Internal Memory | 16 GB | |
| Expandable Memory | yes Up to 32 GB | |
| Graphics | Mali-400 MP2 | |
| SIM Slot(s) | Dual SIM, GSM GSM | |
| Display | Itel S21 | other phones |
| Screen Size | 5 inches (12.7 cm) | |
| Screen Resolution | 480 x 854 pixels | |
| Display Type | TFT | |
| Pixel Density | 196 ppi | |
| Touch Screen | yes Capacitive Touchscreen, Multi-touch | |
| Main Camera | Itel S21 | other phones |
| Resolution | 8 MP Primary Camera
| |
| Image Resolution | 3264 x 2448 Pixels | |
| Flash | yes Dual LED Flash | |
| Camera Features | Digital Zoom, Auto Flash, Face detection, Touch to focus | |
| Autofocus | yes | |
| Shooting Modes | Continuos Shooting, High Dynamic Range mode (HDR) | |
| Settings | Exposure compensation, ISO control | |
| Front Camera | Itel S21 | other phones |
| Resolution | 5 MP Primary Camera
| |
| Flash | yes LED Flash | |
| Camera Features | Wide Angle Selfie | |
| Connectivity | Itel S21 | other phones |
| Network | 4G: Available ,
3G: Available, 2G: Available | |
| SIM 2 | 2G Bands: GSM 1800 / 1900 / 850 / 900 MHz
| |
| Bluetooth | yes v4.1 | |
| GPS | yes | |
| NFC | No | |
| VoLTE | yes | |
| Wi-Fi | yes Wi-Fi 802.11, b/g/n | |
| Wi-Fi Features | Mobile Hotspot | |
| USB Connectivity | microUSB 2.0 | |
| Multimedia | Itel S21 | other phones |
| Audio Jack | 3.5 mm | |
| FM Radio | yes | |
| Loudspeaker | yes | |
| Design | Itel S21 | other phones |
| Colours | Moonlight Silver, Champagne Gold, Elegant Black | |
| Battery | Itel S21 | other phones |
| Type | Li-Polymer | |
| Capacity | 2700 mAh | |
| USB Type-C | No | |
| Features | Itel S21 | other phones |
| Fingerprint Sensor | yes | |
| Fingerprint Sensor Position | Rear | |
