Some Samsung smartphones are literally like you would want to smash them on the floor when they stop working while you are operating them and this is one of the same devices. However, when you invest a lot of money on them, you have to make sure to operate them for some time. Samsung Galaxy M21 is a very slow worker and buy it only when you have a lot of patience. It has terrible camera section and the Exynos chipset in it is also a bad performer. Only the battery backup in the device is a bit good, otherwise there are no features to tell. Not recommended.