| Hardware and OS | Nokia Lumia 900 AT&T | Oppo A3s |
| Operating system | Microsoft Windows Phone 7.5 Mango | Android 8.1 (Oreo); ColorOS 5.1 |
| Processor | 1.4 GHz Scorpion | Octa-core 1.8 GHz Cortex-A53 |
| Chipset | Qualcomm APQ8055 Snapdragon S2 | Qualcomm SDM450 Snapdragon 450 (14 nm) |
| GPU | Adreno 205 | Adreno 506 |
| Internal memory | 16GB 512MB RAM | 16 GB, 2 GB RAM |
| External memory | No | microSD, up to 256 GB (dedicated slot) |
| Display | Nokia Lumia 900 AT&T | Oppo A3s |
| Type | AMOLED capacitive touchscreen, 16M colors | IPS LCD |
| Size | 4.3 inches, 52.6 cm2 | 6.2" inc |
| Resolution | 480 x 800 pixels, 5:3 ratio | 720 x 1520 px |
| Touchscreen | | capacitive touchscreen |
| Protection | Corning Gorilla Glass | |
| Screen-to-Body Ratio | | 81.2% |
| Display area | | 95.9 cm2 |
| Display aspect ratio | | 19:9 (height:width) |
| Pixel Density | | 271 PPI |
| Colors | | 16M |
| Main Camera | Nokia Lumia 900 AT&T | Oppo A3s |
| Camera | 8 MP, AF | |
| Features | Carl Zeiss optics, dual-LED flash | |
| Video | 720p@30fps | |
| Selfie camera | Nokia Lumia 900 AT&T | Oppo A3s |
| Camera | 1.3 MP | |
| Video | VGA@30fps | |
| Connectivity | Nokia Lumia 900 AT&T | Oppo A3s |
| 2G Network | GSM 850 / 900 / 1800 / 1900 | GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2 |
| 3G Network | HSDPA 850 / 1900 / 2100 | HSDPA 850 / 900 / 2100 |
| 4G Network | LTE band 4(1700/2100), 17(700) | LTE |
| Wi-Fi | | Wi-Fi 802.11 b/g/n, WiFi Direct, hotspot |
| Network | | GSM / HSPA / LTE |
| SIM card | | Dual SIM (Nano-SIM, dual stand-by) |
| Bluetooth | 2.1, A2DP, EDR | 4.2, A2DP, LE |
| Edge | | Yes |
| GPRS | | Yes |
| Technology | GSM / HSPA / LTE | |
| GPS | Yes, with A-GPS | Yes, with A-GPS |
| Speed | HSPA 21.1/5.76 Mbps, LTE Cat3 100/50 Mbps | HSPA 42.2/5.76 Mbps, LTE-A (2CA) Cat6 300/50 Mbps |
| WLAN | Wi-Fi 802.11 b/g/n | |
| USB | microUSB 2.0 | microUSB 2.0, USB On-The-Go |
| Camera | Nokia Lumia 900 AT&T | 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 | Nokia Lumia 900 AT&T | Oppo A3s |
| Loudspeaker | Yes | |
| 3.5 mm Jack | Yes | Yes |
| Radio | Stereo FM radio, RDS | FM radio |
| Design | Nokia Lumia 900 AT&T | Oppo A3s |
| Colors | Matte black, cyan, pink | Red, Dark Purple |
| SIM | Micro-SIM | |
| Dimensions | 127.8 x 68.5 x 11.5 mm, 90 cc (5.03 x 2.70 x 0.45 in) | 156.2 x 75.6 x 8.2 mm |
| Weight | 160 g (5.64 oz) | 168 g |
| Features | Nokia Lumia 900 AT&T | Oppo A3s |
| Sensors | Accelerometer, gyro, proximity, compass | |
| Battery | Nokia Lumia 900 AT&T | Oppo A3s |
| Capacity | Non-removable Li-Ion 1830 mAh battery (BP-6EW) | |
| Stand-by | Up to 300 h | |
| Talk time | Up to 7 h | |
| Battery capacity | | 4230 mAh, Non-removable Li-Ion |
| Other | Nokia Lumia 900 AT&T | Oppo A3s |
| Release date | | 2018, July |
| Sensors | | Accelerometer, proximity, compass |
