The availability feature checks whether your devices are online. The availability state of a device is published to zigbee2mqtt/[FRIENDLY_NAME]/availability (this message is a retained MQTT message).

# Optional: Enable the availability feature (default = false)
availability: true

The availability feature works differently for active and passive devices.

  • Active devices (routers or mains powered end devices): by default they have to check-in every 10 minutes. If they don't, they will be pinged, if that fails the device will be marked as offline.
  • Passive devices (everything that is not an active device, mostly battery powered devices): these devices need to check-in every 25 hours, they cannot be pinged so if they don't they will be marked as offline.

Note that this timeout is persisted between Zigbee2MQTT restarts. So if you for example stop Zigbee2MQTT for longer than 10 minutes, all your active devices will be marked as offline initially.

Availability advanced configuration

Instead of setting availability: true in your configuration.yaml you can provide a more advanced configuration:

# Note: all options are optional
    # Time after which an active device will be marked as offline in
    # minutes (default = 10 minutes)
    timeout: 10
    # Time after which a passive device will be marked as offline in
    # minutes (default = 1500 minutes aka 25 hours)
    timeout: 1500

    friendly_name: 'my_bulb'
    # Set availability: false to disable the availability feature for a specific device
    availability: false
    friendly_name: 'my_switch'
    # Change availability timeout to 3 minutes for this device only
      timeout: 3

If you want to enable the availability feature for only certain devices, don't add availability: true in your configuration.yaml but specify it for that device only, e.g.

    friendly_name: 'my_switch'
    # Enable availability for just 'my_switch'
    availability: true

State retrieval

When the availability feature is enabled and a device reconnects or announces itself on the network, Zigbee2MQTT will retrieve the state of the device. This is e.g. handy when a bulb turns itself on after being reconnected to mains power. The following attributes will be read: state, brightness, color_temp and color.

Performance considerations

  • The pinging can be heavy on the coordinator, especially if you are using a CC2530 or CC2531 adapter.
  • Higher timeout for active devices results in less pinging so less stress on the coordinator.

Availability payload

By default the published availability payload is in legacy mode (online/offline). If the legacy mode is disabled the payload will be a JSON object ({"state":"online"}/{"state":"offline"}). Note that this changes the payload for zigbee2mqtt/bridge/state and zigbee2mqtt/MY_DEVICE/availability.

  # Whether to use legacy mode for the availability message payload (default: true)
  # true = online/offline
  # false = {"state":"online"} / {"state":"offline"}
  legacy_availability_payload: true


When enabling device availability, availability will also be enabled for groups. A group is marked as available when at least one device in it is available.