developers.home-assistant/docs/core/entity/binary-sensor.md

title	sidebar_label
Binary Sensor Entity	Binary Sensor

A binary sensor is a sensor that can only have two states.

Properties

:::tip Properties should always only return information from memory and not do I/O (like network requests). Implement update() or async_update() to fetch data. :::

Name	Type	Default	Description
is_on	boolean	Required	If the binary sensor is currently on or off.
device_class	string	None	Type of binary sensor.

Available device classes

Value	Description
battery	On means low, Off means normal.
battery_charging	On means charging, Off means not charging.
cold	On means cold, Off means normal.
connectivity	On means connected, Off means disconnected.
door	On means open, Off means closed.
garage_door	On means open, Off means closed.
gas	On means gas detected, Off means no gas (clear).
heat	On means hot, Off means normal.
light	On means light detected, Off means no light.
lock	On means open (unlocked), Off means closed (locked).
moisture	On means wet, Off means dry.
motion	On means motion detected, Off means no motion (clear).
moving	On means moving, Off means not moving (stopped).
occupancy	On means occupied, Off means not occupied (clear).
opening	On means open, Off means closed.
plug	On means plugged in, Off means unplugged.
power	On means power detected, Off means no power.
presence	On means home, Off means away.
problem	On means problem detected, Off means no problem (OK).
safety	On means unsafe, Off means safe.
smoke	On means smoke detected, Off means no smoke (clear).
sound	On means sound detected, Off means no sound (clear).
vibration	On means vibration detected, Off means no vibration.
window	On means open, Off means closed.