| Hardware and OS | Celkon Millennia Spark | Oppo A3s |
| Operating system | Android v4.4 (Kitkat) | Android 8.1 (Oreo); ColorOS 5.1 |
| Processor | Quad core, 1.2 GHz | Octa-core 1.8 GHz Cortex-A53 |
| Chipset | | Qualcomm SDM450 Snapdragon 450 (14 nm) |
| RAM | 512 MB | |
| GPU | | Adreno 506 |
| Internal memory | 4 GB | 16 GB, 2 GB RAM |
| Expandable Memory | Yes, Up to 32 GB | |
| External memory | | microSD, up to 256 GB (dedicated slot) |
| Display | Celkon Millennia Spark | Oppo A3s |
| Screen Size | 4.5 inches (11.43 cm) | |
| Type | | IPS LCD |
| Size | | 6.2" inc |
| Display Type | TFT | |
| Resolution | 480 x 854 pixels | 720 x 1520 px |
| Touchscreen | | capacitive touchscreen |
| Touch Screen | Yes, Capacitive Touchscreen, Multi-touch | |
| Screen-to-Body Ratio | | 81.2% |
| Display area | | 95.9 cm2 |
| Display aspect ratio | | 19:9 (height:width) |
| Pixel Density | 218 ppi | 271 PPI |
| Colors | | 16M |
| Main Camera | Celkon Millennia Spark | Oppo A3s |
| Resolution | 3.2 MP Primary Camera
| |
| Image Resolution | 2048 x 1536 Pixels | |
| Flash | Yes, LED Flash | |
| Camera Features | Digital Zoom | |
| Camera Setup | Single | |
| Connectivity | Celkon Millennia Spark | 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, b/g/n | Wi-Fi 802.11 b/g/n, WiFi Direct, hotspot |
| Network | 3G, 2G | GSM / HSPA / LTE |
| SIM card | | Dual SIM (Nano-SIM, dual stand-by) |
| SIM 1 | 3G Bands: UMTS 2100 MHz 2G Bands: GSM 1800 / 900 MHz
GPRS: Available EDGE: Available | |
| Bluetooth | Yes | 4.2, A2DP, LE |
| SIM 2 | 2G Bands: GSM 1800 / 900 MHz
| |
| Edge | | Yes |
| GPRS | | Yes |
| GPS | Yes | Yes, with A-GPS |
| Speed | | HSPA 42.2/5.76 Mbps, LTE-A (2CA) Cat6 300/50 Mbps |
| USB Connectivity | microUSB 2.0 | |
| USB | | microUSB 2.0, USB On-The-Go |
| Front Camera | Celkon Millennia Spark | Oppo A3s |
| Resolution | 1.3 MP Primary Camera
| |
| Camera Setup | Single | |
| Camera | Celkon Millennia Spark | 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 | Celkon Millennia Spark | Oppo A3s |
| Audio Jack | 3.5 mm | |
| FM Radio | Yes | |
| 3.5 mm Jack | | Yes |
| Radio | | FM radio |
| Design | Celkon Millennia Spark | Oppo A3s |
| Height | 133.5 mm | |
| Width | 66.5 mm | |
| Thickness | 10.1 mm | |
| Colours | Blue, Brown, Gold, White | |
| Colors | | Red, Dark Purple |
| Dimensions | | 156.2 x 75.6 x 8.2 mm |
| Weight | 100 grams | 168 g |
| Features | Celkon Millennia Spark | Oppo A3s |
| Other Sensors | Proximity sensor, Accelerometer | |
| Battery | Celkon Millennia Spark | Oppo A3s |
| Type | Li-ion | |
| Capacity | 1600 mAh | |
| Standby time | Up to 200 Hours(2G) | |
| TalkTime | Up to 8 Hours(2G) | |
| Battery capacity | | 4230 mAh, Non-removable Li-Ion |
| Other | Celkon Millennia Spark | Oppo A3s |
| Release date | | 2018, July |
| Sensors | | Accelerometer, proximity, compass |
