The Samsung Galaxy M31 sports a 6.4-inch full HD+ Super AMOLED Infinity-U display. Whereas, the Galaxy M31s sports a slightly larger 6.5-inch full HD+ Super AMOLED Infinity-O display. So basically, the screen to body is larger on the M31s, due to the hole punch over the waterdrop style notch and smaller bezels overall.
Both the devices are powered by the company’s own Exynos 9611 processor. Both run Google’s Android 10 operating system with the company’s own One UI 2.0 skin on top.
The Galaxy M31s is offered in two variants: 6GB RAM/128GB storage and 8GB RAM/128GB storage. Whereas, the Galaxy M31 comes in three variants: 6GB RAM/64GB storage, 6GB RAM/128GB storage and 8GB RAM/64GB storage.
The Galaxy M31 sport a quad camera setup, similar to the Galaxy M31s.
BATTERY- both the devices are backed by a 6,000mAh battery. However, the charging technologies used are different. The Galaxy M31 comes with support for 15W fast charging, but the Galaxy M31s comes with support for 25W charging.
While the Galaxy M31s has a side-mounted fingerprint scanner, the M31 features a rear-mounted fingerprint scanner.
The Galaxy M31 sport a quad camera setup, similar to the Galaxy M31s, but the sensors used are different. The Galaxy M31 sports a 64MP primary Samsung ISOCELL Bright GW1 sensor paired with an 8MP ultra wide angle lens, 5MP depth sensor and a 5MP macro lens. The Galaxy M31s comes with a better 64MP primary Sony IMX682 sensor paired with a 12MP ultra wide angle lens, a 5MP depth sensor and a 5MP macro lens.
On the front, both the devices feature a 32MP sensor for taking selfies and with support for 4K video recording.