Start light fade

Use this action to start fading a UPB light up or down from its current brightness to a target level. Lights that are not dimmable ignore the fade.

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 start a light fade 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 your UPB light.
  6. From the actions shown for that target, select Start light fade.
  7. Enter the target brightness and the rate, then select Save.

Options in the UI

Brightness (Optional)

The target brightness, where 0 turns the light off, 1 is the minimum brightness, and 255 is the maximum brightness. Set either Brightness or Brightness percentage, but not both.

Brightness percentage (Optional)

The target brightness as a percentage, where 0 turns the light off, 1 is the minimum brightness, and 100 is the maximum brightness. Set either Brightness or Brightness percentage, but not both.

Rate (Optional)

The time in seconds for the light to transition to the new brightness. The UPB system rounds this to the nearest supported time. See Rate transition time for how this value is interpreted. A value of -1 uses the device default rate.

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 upb.light_fade_start. A basic example looks like this:

ActionActions are used in several places in Home Assistant. As part of a script or automation, actions define what is going to happen once a trigger is activated. In scripts, an action is called *sequence*. [Learn more]
action: upb.light_fade_start
target:
  entity_id: light.kitchen
data:
  brightness_pct: 75
  rate: 10

Options in YAML

brightness integer

The target brightness, where 0 turns the light off, 1 is the minimum brightness, and 255 is the maximum brightness. Set either brightness or brightness_pct, but not both.

brightness_pct float

The target brightness as a percentage, where 0 turns the light off, 1 is the minimum brightness, and 100 is the maximum brightness. Set either brightness or brightness_pct, but not both.

rate float

The time in seconds for the light to transition to the new brightness. The UPB system rounds this to the nearest supported time. See Rate transition time for how this value is interpreted. A value of -1 uses the device default rate.

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 light entity behind that target.

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

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.

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.

Tip

AI assistants like ChatGPT or Claude can also explain actions or suggest the right one when you describe what you want in plain language.

Related actions

These actions work well alongside this one: