| Hardware and OS | Zen Ultrafone 303 | Oppo A3s |
| Operating system | Android v4.0 (Ice Cream Sandwich) | Android 8.1 (Oreo); ColorOS 5.1 |
| Processor | 1 GHz | Octa-core 1.8 GHz Cortex-A53 |
| Chipset | | Qualcomm SDM450 Snapdragon 450 (14 nm) |
| RAM | 256 MB | |
| GPU | | Adreno 506 |
| Internal memory | 512 MB | 16 GB, 2 GB RAM |
| Expandable Memory | yes Up to 32 GB | |
| External memory | | microSD, up to 256 GB (dedicated slot) |
| SIM Slot(s) | Dual SIM | |
| Display | Zen Ultrafone 303 | Oppo A3s |
| Type | | IPS LCD |
| Screen Size | 4 inches (10.16 cm) | |
| Size | | 6.2" inc |
| Screen Resolution | 480 x 800 pixels | |
| Resolution | | 720 x 1520 px |
| Display Type | IPS LCD | |
| Touchscreen | | capacitive touchscreen |
| Screen-to-Body Ratio | | 81.2% |
| Touch Screen | yes Capacitive Touchscreen | |
| Display area | | 95.9 cm2 |
| Display aspect ratio | | 19:9 (height:width) |
| Pixel Density | 233 ppi | 271 PPI |
| Colors | | 16M |
| Main Camera | Zen Ultrafone 303 | Oppo A3s |
| Resolution | 3.2 MP Primary Camera
| |
| Image Resolution | 2048 x 1536 Pixels | |
| Flash | yes LED Flash | |
| Camera Features | Digital Zoom | |
| Connectivity | Zen Ultrafone 303 | Oppo A3s |
| 2G Network | | GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2 |
| 3G Network | | HSDPA 850 / 900 / 2100 |
| 4G Network | | LTE |
| Wi-Fi | yes Wi-Fi 802.11 | Wi-Fi 802.11 b/g/n, WiFi Direct, hotspot |
| Network | 2G: Available | GSM / HSPA / LTE |
| SIM 1 | 2G Bands: GSM 900 / 1800
| |
| SIM card | | Dual SIM (Nano-SIM, dual stand-by) |
| SIM 2 | 2G Bands: GSM 900 / 1900
| |
| Bluetooth | yes | 4.2, A2DP, LE |
| SIM Size | SIM1: Micro | |
| Edge | | Yes |
| GPRS | | Yes |
| GPS | | Yes, with A-GPS |
| Speed | | HSPA 42.2/5.76 Mbps, LTE-A (2CA) Cat6 300/50 Mbps |
| USB | | microUSB 2.0, USB On-The-Go |
| Front Camera | Zen Ultrafone 303 | Oppo A3s |
| Resolution | 0.3 MP Primary Camera
| |
| Camera | Zen Ultrafone 303 | Oppo A3s |
| Main camera | | 13 MP, Dual |
| Specs | | 13 MP, f/2.2, AF
-2 MP, f/2.4, depth sensor |
| Features | | LED flash, HDR, panorama |
| Video | | 1080p@30fps |
| Selfie camera | | 8 MP, Single |
| Multimedia | Zen Ultrafone 303 | Oppo A3s |
| Audio Jack | 3.5 mm | |
| FM Radio | yes | |
| Loudspeaker | yes | |
| 3.5 mm Jack | | Yes |
| Radio | | FM radio |
| Design | Zen Ultrafone 303 | Oppo A3s |
| Height | 124.1 mm | |
| Width | 65.3 mm | |
| Thickness | 10.8 mm | |
| Colours | Black, White, Blue | |
| Colors | | Red, Dark Purple |
| Dimensions | | 156.2 x 75.6 x 8.2 mm |
| Weight | 95 grams | 168 g |
| Features | Zen Ultrafone 303 | Oppo A3s |
| Applications | Zen Store, HS18, Notebook | |
| Other Sensors | Proximity sensor, Accelerometer, Gyroscope | |
| Battery | Zen Ultrafone 303 | Oppo A3s |
| Type | Li-ion | |
| Capacity | 1500 mAh | |
| Standby time | Up to 120 Hours(2G) | |
| TalkTime | Up to 6 Hours(2G) | |
| Battery capacity | | 4230 mAh, Non-removable Li-Ion |
| Other | Zen Ultrafone 303 | Oppo A3s |
| Release date | | 2018, July |
| Sensors | | Accelerometer, proximity, compass |
