Oppo A31 smartphone comes with a 6.50-inch touchscreen display with a resolution of 720×1600 pixels and an aspect ratio of 20:9. Oppo A31 is powered by a 2.3GHz octa-core MediaTek Helio P35 (MT6765) processor. It comes with 4GB of RAM. The Oppo A31 runs Android 9 and is powered by a 4230mAh non-removable battery. As far as the cameras are concerned, the Oppo A31 on the rear packs a 12-megapixel primary camera with an f/1.8 aperture; a second 2-megapixel camera with an f/2.4 aperture and a pixel size of 1.75-micron and a third 2-megapixel camera with an f/2.4 aperture and a pixel size of 1.75-micron. The rear camera setup has autofocus. It sports a 8-megapixel camera on the front for selfies, with an f/2.0 aperture. The Oppo A31 runs ColorOS 6.1.2 based on Android 9 and packs 128GB of inbuilt storage that can be expanded via microSD card (up to 256GB) with a dedicated slot. The Oppo A31 is a dual-SIM (GSM and GSM) smartphone that accepts Nano-SIM and Nano-SIM cards. The Oppo A31 measures 163.90 x 75.50 x 8.30mm (height x width x thickness) and weighs 180.00 grams. It was launched in Mystery Black and Fantasy White colours. It bears a plastic body. Connectivity options on the Oppo A31 include Wi-Fi 802.11 a/b/g/n/ac, GPS, Bluetooth v5.00, Micro-USB, FM radio, 3G, and 4G. Sensors on the phone include accelerometer, ambient light sensor, compass/ magnetometer, proximity sensor, and fingerprint sensor. The Oppo A31 supports face unlock.