Transition on

Use this action to ease a Snooz white noise machine to a volume over time instead of jumping to it instantly. If the device is off, the transition starts at the lowest volume. This is a gentle way to fade sound in, for example when winding down for sleep.

Using this action from the user interface

If you prefer building automations and scripts visually, Home Assistant walks you through this action step by step. You pick what to target, tweak a few options, and save. No YAML knowledge required.

To transition a Snooz device on from an automation or a script:

1. Go to Settings > Automations & scenes.
2. Open an existing automation or script, or select Create automation > Create new automation.
3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger. They run when something else calls them.
4. In the Then do section, select Add action.
5. Select what you want to control. Under By target (see Targets), select the area, floor, device, label, or entity you want to control.
6. From the actions shown for that target, select Transition on.
7. Optionally set the Target volume and Transition duration.
8. Select Save.

Options in the UI

Using this action in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this action as snooz.transition_on. A basic example looks like this:

action: snooz.transition_on
target:
  entity_id: fan.snooz_bedroom
data:
  volume: 33
  duration: 120

This fades fan.snooz_bedroom up to 33% volume over two minutes.

Options in YAML

Targets of the action

This action requires a target. The target is the object of the action. You can point the action at a single entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more], a device, an area, a floor, or a label, and Home Assistant will run the action on every matching fan entity behind that target.

• Entity: one specific fan entity, such as fan.living_room.
• Device: every fan entity that belongs to a device.
• Area: every fan entity in a room or area.
• Floor: every fan entity on a floor.
• Label: every fan entity that shares a label.

You can also select different target types in one action. For example, you can add a specific entity and an area as targets in the same action to run the action on both of them at once.

Good to know

• If the device is off when the transition starts, it begins at the lowest volume and rises to the target.
• Volume maps to the fan speed percentage of the Snooz entity.

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] without writing a line of YAML.

More examples

Real scenarios where this action shows up in automations and scripts. Copy any example and adapt it to your setup.

Automation: fade noise in at bedtime

Use this automation to slowly bring the white noise up to a comfortable level at bedtime.

• Trigger: Time: 22:00
• Action: Transition on
  • Target: Bedroom Snooz
  • Target volume: 33
  • Transition duration: 120

- alias: "Fade the bedroom Snooz in at bedtime"
  triggers:
    - trigger: time
      at: "22:00:00"
  actions:
    - action: snooz.transition_on
      target:
        entity_id: fan.snooz_bedroom
      data:
        volume: 33
        duration: 120

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the action you’re calling and what you expected to happen, or share on our subreddit /r/homeassistant.

Related actions

These actions work well alongside this one:

• Transition off: Gradually lowers a Snooz device’s volume, then turns it off.