The OPPO A91 was announced in 2019, December 20 With 6.4 inches, 100.4 cm2 (~85.5% screen-to-body ratio) AMOLED, 430 nits (typ), Powered by Mediatek MT6771V Helio P70 (12nm) and running Android 9.0 (Pie), upgradable to Android 11, ColorOS 11, the device delivered smooth performance and multitasking capabilities. while the Li-Po 4025 mAh, non-removable ensured long-lasting usage.