A contact sensor is one of the simplest ways to create a security perimeter around your home. This tiny device helps you know when a window's open or a door's ajar. Our top door and window sensor pick is the Mirabella Genio Door and Window Sensor, which connects to your smartphone without any need for a smart hub. It's also reasonably priced (under $30) and ties in nicely with other Mirabella Genio products to trigger smart home scenes.
For those looking for an even cheaper option or a product that works with Apple HomeKit, check out our door and window sensor picks below.