Like other mid-range devices from Vivo, the Vivo S1 is quite a looker. The handset features a metal body wrapped around a layer of toughened glass. The phone is also offered in dual tone color variants thereby enhancing the overall premiums of the device. The front fascia of the Vivo S1 is dominated by the huge 6.53-inch IPS LCD display that boasts of full HD+ resolution (1080 x 2340 pixels) and a PPI density value of 395.

At the heart of the Vivo S1 is the all-important MediaTek Helio P70 chipset. This SoC which competes with the Qualcomm Snapdragon 660 is based on a 12nm manufacturing process and is an octa-core chipset that comes with four Cortex-A53 little cores operating at up to 2 GHz and four Cortex-A73 cores operating at up to 2.1 Ghz. Additionally, the chipset also uses the powerful Mali-G72 GPU for graphics. While the chipset supports up to 8GB of RAM, the Vivo S1 ships with 6GB of RAM.

The camera setup on the Vivo S1 consists of a 12-megapixel primary camera and a secondary 8-megapixel camera - both of which are mated to a third 5-megapixel camera which performs the duty of a depth sensor. These three cameras aside, the Vivo S1 also incorporates a fourth camera at the front which happens to be a 25-megapixel unit for selfies and video calling. The Vivo S1 also packs in a large 3940 mAh battery under the hood which promises day-long battery life. The handset also boasts of a wide array of connectivity options that include Wi-Fi b/g/n/ac, India 4G VoLTE bands, USB OTG, Bluetooth, and GPS