| Hardware and OS | Lava Z66 | Oppo A3s |
| Operating system | Android v10 (Q) | Android 8.1 (Oreo); ColorOS 5.1 |
| Processor | Octa core, 1.6 GHz | Octa-core 1.8 GHz Cortex-A53 |
| Chipset | | Qualcomm SDM450 Snapdragon 450 (14 nm) |
| RAM | 3 GB | |
| GPU | | Adreno 506 |
| Internal memory | 32 GB | 16 GB, 2 GB RAM |
| Expandable Memory | yes Up to 128 GB | |
| External memory | | microSD, up to 256 GB (dedicated slot) |
| SIM Slot(s) | Dual SIM, GSM GSM | |
| Display | Lava Z66 | Oppo A3s |
| Type | | IPS LCD |
| Screen Size | 6.08 inches (15.44 cm) | |
| Size | | 6.2" inc |
| Screen Resolution | 720 x 1560 pixels | |
| Resolution | | 720 x 1520 px |
| Display Type | IPS LCD | |
| Touchscreen | | capacitive touchscreen |
| Screen-to-Body Ratio | | 81.2% |
| Aspect Ratio | 19:9 | |
| Display area | | 95.9 cm2 |
| Touch Screen | yes Capacitive Touchscreen, Multi-touch | |
| Display aspect ratio | | 19:9 (height:width) |
| Pixel Density | 283 ppi | 271 PPI |
| Colors | | 16M |
| Main Camera | Lava Z66 | Oppo A3s |
| Resolution | 13 MP f/2.0 Primary Camera(1.12µm pixel size)5 MP, Depth Camera
| |
| Image Resolution | 4128 x 3096 Pixels | |
| Flash | yes LED Flash | |
| Camera Features | Digital Zoom, Auto Flash, Face detection, Touch to focus | |
| Autofocus | yes | |
| Physical Aperture | F2.0 | |
| Video Recording | 1920x1080 @ 30 fps | |
| Shooting Modes | Continuos Shooting, High Dynamic Range mode (HDR), Burst mode | |
| Settings | Exposure compensation, ISO control | |
| Connectivity | Lava Z66 | 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 | 4G: Available ,
3G: Available, 2G: Available | GSM / HSPA / LTE |
| SIM card | | Dual SIM (Nano-SIM, dual stand-by) |
| Bluetooth | yes v4.2 | 4.2, A2DP, LE |
| Edge | | Yes |
| GPRS | | Yes |
| GPS | yes with A-GPS, Glonass | 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 |
| SIM Size | SIM1: Nano, SIM2: Nano | |
| NFC | No | |
| VoLTE | yes | |
| Wi-Fi Features | Mobile Hotspot | |
| USB Connectivity | Mass storage device, USB charging, microUSB 2.0 | |
| Front Camera | Lava Z66 | Oppo A3s |
| Resolution | 13 MP f/2.2 Primary Camera(1.12µm pixel size) | |
| Flash | yes Screen flash | |
| Physical Aperture | F2.2 | |
| Camera | Lava Z66 | 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 | Lava Z66 | Oppo A3s |
| 3.5 mm Jack | | Yes |
| Radio | | FM radio |
| Audio Jack | 3.5 mm | |
| FM Radio | yes | |
| Loudspeaker | yes | |
| Design | Lava Z66 | Oppo A3s |
| Colors | | Red, Dark Purple |
| Dimensions | | 156.2 x 75.6 x 8.2 mm |
| Weight | 162 grams | 168 g |
| Height | 155.6 mm | |
| Width | 73.5 mm | |
| Thickness | 8.8 mm | |
| Colours | Midnight Blue, Marine Blue, Berry Red | |
| Battery | Lava Z66 | Oppo A3s |
| Battery capacity | | 4230 mAh, Non-removable Li-Ion |
| Type | Li-Polymer | |
| Capacity | 3950 mAh | |
| User Replaceable | No | |
| TalkTime | Up to 16 Hours(3G) / Up to 38 Hours(2G) | |
| USB Type-C | No | |
| USB OTG Support | yes | |
| Other | Lava Z66 | Oppo A3s |
| Release date | | 2018, July |
| Sensors | | Accelerometer, proximity, compass |
| Features | Lava Z66 | Oppo A3s |
| Fingerprint Sensor | yes | |
| Fingerprint Sensor Position | Rear | |
| Other Sensors | Light sensor, Proximity sensor, Accelerometer | |
