| Hardware and OS | OPPO F21 | |
| Operating system | Android 10, ColorOS 7.2 | |
| Processor | Octa-core (2x2.0 GHz Cortex-A76, 6x2.0 GHz Cortex-A55) | |
| GPU | Adreno 610 | |
| RAM | 8 GB | |
| Internal Storage | 128 GB | |
| Memory Card Slot | microSDXC (dedicated slot) | |
| User Interface | Yes with Modified Android | |
| Display | OPPO F21 | other phones |
| Type | IPS LCD | |
| Size | 6.5 inches | |
| Resolution | 1080 x 2400 pixels | |
| Colors | 16M Colors | |
| Pixel Density | ~ 405 ppi | |
| Touchscreen | Yes Multi Touch Support | |
| Connectivity | OPPO F21 | other phones |
| 4G Network | 1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 38, 39, 40, 41, 66 | |
| 5G Network | 1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 77, 78 SA/NSA | |
| Wi-Fi | Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, hotspot | |
| GPS | Yes, with A-GPS, GLONASS, GALILEO, BDS | |
| NFC | Yes | |
| USB | USB Type-C 2.0, USB On-The-Go | |
| Speed | HSPA 42.2/5.76 Mbps, LTE-A | |
| SIM | Nano SIM | |
| Dual SIM | Dual SIM (Nano-SIM, dual stand-by) | |
| Wireless Charging | No | |
| Camera | OPPO F21 | other phones |
| Main camera | 16 MP (wide), 8 MP (ultrawide), 2 MP (depth) | |
| Features | LED flash, HDR, panorama | |
| Image | 1080p | |
| Selfie camera | 8 MP (wide) | |
| Multimedia | OPPO F21 | other phones |
| Loudspeaker | Yes | |
| Handsfree | Yes | |
| Radio | Yes | |
| Video Playback | Yes | |
| Video Out | Yes | |
| Ring Tones | Yes | |
| 3.5 mm Jack | Yes | |
| Design | OPPO F21 | other phones |
| Dimensions | 162.2 x 75 x 7.9 mm | |
| Waterproof | No | |
| Weight | 177 Grams | |
| Battery | OPPO F21 | other phones |
| Capacity | Li-Po 4,500 mAh, Fast charging 64W | |
| Placement | Non-Removable | |
| Other | OPPO F21 | other phones |
| Sensors | Fingerprint (side-mounted), accelerometer, proximity, | |
