This Hall sensor knows whether there is a magnetic object nearby or not. And it correctly tells you through ditigal output.See below picture for a quick demo!
Note: It’s a omnipolar magnet dectector so that it can not tell two polarities apart.

Specifications:

Supply Voltage: 3.3V to 5V
Indicator LED on board
Interface: Digital
Size:22x30mm (0.87×1.18″”””)