2025.10.4
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MQTT Humidifier

The mqtt humidifier platform lets you control your MQTT enabled humidifiers.

Configuration

In an ideal scenario, the MQTT device will have a state_topic to publish state changes. If these messages are published with a RETAIN flag, the MQTT humidifier will receive an instant state update after subscription and will start with the correct state. Otherwise, the initial state of the humidifier will be unknown. A MQTT device can reset the current state to unknown using a None payload.

When a state_topic is not available, the humidifier will work in optimistic mode. In this mode, the humidifier will immediately change state after every command. Otherwise, the humidifier will wait for state confirmation from the device (message from state_topic). The initial state is set to False / off in optimistic mode.

Optimistic mode can be forced even if a state_topic is available. Try to enable it if you are experiencing incorrect humidifier operation.

To use an MQTT humidifier in your installation, add the following to your configuration.yamlThe configuration.yaml file is the main configuration file for Home Assistant. It lists the integrations to be loaded and their specific configurations. In some cases, the configuration needs to be edited manually directly in the configuration.yaml file. Most integrations can be configured in the UI. [Learn more] file. After changing the configuration.yamlThe configuration.yaml file is the main configuration file for Home Assistant. It lists the integrations to be loaded and their specific configurations. In some cases, the configuration needs to be edited manually directly in the configuration.yaml file. Most integrations can be configured in the UI. [Learn more] file, restart Home Assistant to apply the changes.

# Example configuration.yaml entry
mqtt:
  - humidifier:
      command_topic: "bedroom_humidifier/on/set"
      target_humidity_command_topic: "bedroom_humidifier/humidity/set"

Alternatively, a more advanced approach is to set it up via MQTT discovery.

Configuration Variables

Looking for your configuration file?
action_template template (Optional)

A template to render the value received on the action_topic with.

action_topic string (Optional)

The MQTT topic to subscribe for changes of the current action. Valid values: off, humidifying, drying, idle

availability list (Optional)

A list of MQTT topics subscribed to receive availability (online/offline) updates. Must not be used together with availability_topic.

payload_available string (Optional, default: online)

The payload that represents the available state.

payload_not_available string (Optional, default: offline)

The payload that represents the unavailable state.

topic string Required

An MQTT topic subscribed to receive availability (online/offline) updates.

value_template template (Optional)

Defines a template to extract device’s availability from the topic. To determine the devices’s availability result of this template will be compared to payload_available and payload_not_available.

availability_mode string (Optional, default: latest)

When availability is configured, this controls the conditions needed to set the entity to available. Valid entries are all, any, and latest. If set to all, payload_available must be received on all configured availability topics before the entity is marked as online. If set to any, payload_available must be received on at least one configured availability topic before the entity is marked as online. If set to latest, the last payload_available or payload_not_available received on any configured availability topic controls the availability.

availability_template template (Optional)

Defines a template to extract device’s availability from the availability_topic. To determine the devices’s availability result of this template will be compared to payload_available and payload_not_available.

availability_topic string (Optional)

The MQTT topic subscribed to receive availability (online/offline) updates. Must not be used together with availability.

current_humidity_template template (Optional)

A template with which the value received on current_humidity_topic will be rendered.

current_humidity_topic string (Optional)

The MQTT topic on which to listen for the current humidity. A "None" value received will reset the current humidity. Empty values (''') will be ignored.

command_template template (Optional)

Defines a template to generate the payload to send to command_topic.

command_topic string Required

The MQTT topic to publish commands to change the humidifier state.

default_entity_id string (Optional)

Use default_entity_id instead of name for automatic generation of the entity ID. For example, humidifier.foobar. When used without a unique_id, the entity ID will update during restart or reload if the entity ID is available. If the entity ID already exists, the entity ID will be created with a number at the end. When used with a unique_id, the default_entity_id is only used when the entity is added for the first time. When set, this overrides a user-customized entity ID if the entity was deleted and added again.

device map (Optional)

Information about the device this humidifier is a part of to tie it into the device registry. Only works when unique_id is set. At least one of identifiers or connections must be present to identify the device.

configuration_url string (Optional)

A link to the webpage that can manage the configuration of this device. Can be either an http://, https:// or an internal homeassistant:// URL.

connections list (Optional)

A list of connections of the device to the outside world as a list of tuples [connection_type, connection_identifier]. For example the MAC address of a network interface: "connections": [["mac", "02:5b:26:a8:dc:12"]].

hw_version string (Optional)

The hardware version of the device.

identifiers string | list (Optional)

A list of IDs that uniquely identify the device. For example a serial number.

manufacturer string (Optional)

The manufacturer of the device.

model string (Optional)

The model of the device.

model_id string (Optional)

The model identifier of the device.

name string (Optional)

The name of the device.

serial_number string (Optional)

The serial number of the device.

suggested_area string (Optional)

Suggest an area if the device isn’t in one yet.

sw_version string (Optional)

The firmware version of the device.

via_device string (Optional)

Identifier of a device that routes messages between this device and Home Assistant. Examples of such devices are hubs, or parent devices of a sub-device. This is used to show device topology in Home Assistant.

device_class string (Optional, default: humidifier)

The device class of the MQTT device. Must be either humidifier, dehumidifier or null.

enabled_by_default boolean (Optional, default: true)

Flag which defines if the entity should be enabled when first added.

encoding string (Optional, default: utf-8)

The encoding of the payloads received and published messages. Set to "" to disable decoding of incoming payload.

entity_category string (Optional)

The category of the entity.

entity_picture string (Optional)

Picture URL for the entity.

icon icon (Optional)

Icon for the entity.

json_attributes_template template (Optional)

Defines a template to extract the JSON dictionary from messages received on the json_attributes_topic. Usage example can be found in MQTT sensor documentation.

json_attributes_topic string (Optional)

The MQTT topic subscribed to receive a JSON dictionary payload and then set as sensor attributes. Usage example can be found in MQTT sensor documentation.

max_humidity float (Optional, default: 100)

The minimum target humidity percentage that can be set.

min_humidity float (Optional, default: 0)

The maximum target humidity percentage that can be set.

name string (Optional, default: MQTT humidifier)

The name of the humidifier. Can be set to null if only the device name is relevant.

optimistic boolean (Optional)

Flag that defines if humidifier works in optimistic mode

Default:

true if no state topic defined, else false.

payload_available string (Optional, default: online)

The payload that represents the available state.

payload_not_available string (Optional, default: offline)

The payload that represents the unavailable state.

payload_off string (Optional, default: OFF)

The payload that represents the stop state.

payload_on string (Optional, default: ON)

The payload that represents the running state.

payload_reset_humidity string (Optional, default: “None”)

A special payload that resets the target_humidity state attribute to an unknown state when received at the target_humidity_state_topic. When received at current_humidity_topic it will reset the current humidity state.

payload_reset_mode string (Optional, default: “None”)

A special payload that resets the mode state attribute to an unknown state when received at the mode_state_topic.

target_humidity_command_template template (Optional)

Defines a template to generate the payload to send to target_humidity_command_topic.

target_humidity_command_topic string Required

The MQTT topic to publish commands to change the humidifier target humidity state based on a percentage.

target_humidity_state_topic string (Optional)

The MQTT topic subscribed to receive humidifier target humidity.

target_humidity_state_template template (Optional)

Defines a template to extract a value for the humidifier target_humidity state.

mode_command_template template (Optional)

Defines a template to generate the payload to send to mode_command_topic.

mode_command_topic string (Optional)

The MQTT topic to publish commands to change the mode on the humidifier. This attribute ust be configured together with the modes attribute.

mode_state_topic string (Optional)

The MQTT topic subscribed to receive the humidifier mode.

mode_state_template template (Optional)

Defines a template to extract a value for the humidifier mode state.

modes list (Optional, default: [])

List of available modes this humidifier is capable of running at. Common examples include normal, eco, away, boost, comfort, home, sleep, auto and baby. These examples offer built-in translations but other custom modes are allowed as well. This attribute ust be configured together with the mode_command_topic attribute.

platform string Required

Must be humidifier. Only allowed and required in MQTT auto discovery device messages.

qos integer (Optional, default: 0)

The maximum QoS level to be used when receiving and publishing messages.

retain boolean (Optional, default: true)

If the published message should have the retain flag on or not.

state_topic string (Optional)

The MQTT topic subscribed to receive state updates. A “None” payload resets to an unknown state. An empty payload is ignored. Valid state payloads are OFF and ON. Custom OFF and ON values can be set with the payload_off and payload_on config options.

state_value_template template (Optional)

Defines a template to extract a value from the state.

unique_id string (Optional)

An ID that uniquely identifies this humidifier. If two humidifiers have the same unique ID, Home Assistant will raise an exception. Required when used with device-based discovery.

Important

Make sure that your topics match exactly. some-topic/ and some-topic are different topics.

Examples

In this section you find some real-life examples of how to use this humidifier.

Full configuration

The example below shows a full configuration for a MQTT humidifier including modes.

# Example configuration.yaml
mqtt:
  - humidifier:
      name: "Bedroom humidifier"
      device_class: "humidifier"
      state_topic: "bedroom_humidifier/on/state"
      action_topic: "bedroom_humidifier/action"
      command_topic: "bedroom_humidifier/on/set"
      current_humidity_topic: "bedroom_humidifier/humidity/current"
      target_humidity_command_topic: "bedroom_humidifier/humidity/set"
      target_humidity_state_topic: "bedroom_humidifier/humidity/state"
      mode_state_topic: "bedroom_humidifier/mode/state"
      mode_command_topic: "bedroom_humidifier/preset/preset_mode"
      modes:
        - "normal"
        - "eco"
        - "away"
        - "boost"
        - "comfort"
        - "home"
        - "sleep"
        - "auto"
        - "baby"
      qos: 0
      payload_on: "true"
      payload_off: "false"
      min_humidity: 30
      max_humidity: 80