| Hardware and OS | BLU G51 | Oppo A3s |
| Operating system | Android 11 (Go edition) | Android 8.1 (Oreo); ColorOS 5.1 |
| Processor | Quad-core 2.0 GHz Cortex-A53 | Octa-core 1.8 GHz Cortex-A53 |
| Chipset | Mediatek MT6761 Helio A22 (12 nm) | Qualcomm SDM450 Snapdragon 450 (14 nm) |
| GPU | PowerVR GE8320 | Adreno 506 |
| Internal memory | 32GB 2GB RAM | 16 GB, 2 GB RAM |
| External memory | microSDXC | microSD, up to 256 GB (dedicated slot) |
| Display | BLU G51 | Oppo A3s |
| Type | IPS LCD | IPS LCD |
| Size | 6.1" inc | 6.2" inc |
| Resolution | 720 x 1520 px | 720 x 1520 px |
| Touchscreen | capacitive touchscreen | capacitive touchscreen |
| Display colors | 16M | |
| Screen-to-Body Ratio | | 81.2% |
| Screen area | 92.9 cm2 | |
| Display area | | 95.9 cm2 |
| Screen format | 19:9 (height:width) | |
| Display aspect ratio | | 19:9 (height:width) |
| Screen to body ratio | 81.4% | |
| Pixel Density | | 271 PPI |
| PPI /points per inch/ | 276 PPI | |
| Colors | | 16M |
| Connectivity | BLU G51 | Oppo A3s |
| 2G Network | | GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2 |
| 3G Network | | HSDPA 850 / 900 / 2100 |
| NFC | No | |
| 4G Network | | LTE |
| Wi-Fi | Wi-Fi 802.11 a/b/g/n, Wi-Fi Direct, hotspot | Wi-Fi 802.11 b/g/n, WiFi Direct, hotspot |
| Network | GSM / HSPA / LTE | GSM / HSPA / LTE |
| SIM card | Dual SIM (Nano-SIM, dual stand-by) | Dual SIM (Nano-SIM, dual stand-by) |
| Bluetooth | 4.2, A2DP, LE | 4.2, A2DP, LE |
| Edge | Yes | Yes |
| GPRS | Yes | Yes |
| GPS | Yes, with A-GPS | Yes, with A-GPS |
| Speed | | HSPA 42.2/5.76 Mbps, LTE-A (2CA) Cat6 300/50 Mbps |
| USB | microUSB 2.0 | microUSB 2.0, USB On-The-Go |
| Camera | BLU G51 | Oppo A3s |
| Rear camera, main | 8 MP, Dual | |
| Camera specs | 8 MP
-0.3 MP (depth) | |
| Functions | LED flash, HDR, panorama | |
| Main camera | | 13 MP, Dual |
| Specs | | 13 MP, f/2.2, AF
-2 MP, f/2.4, depth sensor |
| Front camera, selfie | 8 MP, Single | |
| Features | | LED flash, HDR, panorama |
| Video | 1080p@30fps | 1080p@30fps |
| Selfie camera | | 8 MP, Single |
| Multimedia | BLU G51 | Oppo A3s |
| Headphone jack | Yes | |
| 3.5 mm Jack | | Yes |
| Radio | FM radio | FM radio |
| Design | BLU G51 | Oppo A3s |
| Dimensions (HxWxD) | 155.3 x 73.5 x 9.5 mm | 6.11 x 2.89 x 0.37 in | |
| Colors | Black, Blue, Green, Silver, Gold | Red, Dark Purple |
| Dimensions | | 156.2 x 75.6 x 8.2 mm |
| Weight | 166 g | 5.86 oz | 168 g |
| Other features | BLU G51 | Oppo A3s |
| Sensors | Fingerprint (rear-mounted), accelerometer, proximity | |
| Battery | BLU G51 | Oppo A3s |
| Battery | 3000 mAh, Li-Po | |
| Battery capacity | | 4230 mAh, Non-removable Li-Ion |
| Other | BLU G51 | Oppo A3s |
| Release date | | 2018, July |
| Sensors | | Accelerometer, proximity, compass |
