The Vivo Y91i runs Funtouch OS 4.5 is based on Android 8.1 and packs 16GB of inbuilt storage that can be expanded via microSD card. The Vivo Y91i is a dual-SIM (GSM and GSM) smartphone that accepts Nano-SIM and Nano-SIM cards. The Vivo Y91i measures 155.11 x 75.09 x 8.28mm (height x width x thickness) and weighs 163.50 grams. It was launched in Fusion Black and Ocean Blue colours. Connectivity options on the Vivo Y91i include Wi-Fi, GPS, Bluetooth v5.00, USB OTG, Micro-USB, FM radio, 3G, and 4G (with support for Band 40 used by some LTE networks in India). Sensors on the phone include accelerometer, ambient light sensor, gyroscope, proximity sensor, and compass/ magnetometer. The Vivo Y91i supports face unlock.