The door and window alarms from Wyze Sense come in a pack of four for under $20 from Wyze's website. Other companies charge that much or more for one sensor alone. And we’d guess you have more than one door or window to protect.
Wyze’s sensors are compact and fit in door frames, window sills, and even on cookie jars (for those cookie thieves in your house). Whatever you want to keep closed, these devices make it easy and cheap to do.
If Wyze doesn’t hit the mark for you, we’ve got sensors that work with smart home systems, standalone sensors, and more in our list below. Take your pick from the best door window sensors.