2026.10.4
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Group items by attribute: groupby

The groupby filter groups items in a list by a common attribute, producing a list of (grouper, list) pairs where grouper is the attribute value and list contains all items that share that value.

This is extremely useful when you want to organize 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] by a shared property. For example, you can group lights by their area, sensors by their state, or devices by their manufacturer. The result lets you iterate over each group and display or process the items together. It works especially well with expand to organize large collections of entities into meaningful categories.

Usage

Here’s how to use this template function. Copy any example and adjust it to your setup.

As a filter 
{% for state, entities in expand("light.home_lights") | groupby("state") %}
  {{ state }}: {{ entities | map(attribute="entity_id") | join(", ") }}
{% endfor %}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
off: light.bedroom, light.garage
on: light.kitchen, light.living_room

Function signature

The signature is a technical summary of this template function. It shows the name of the function, the values (called parameters) it accepts, and what type of data each parameter expects (for example, a piece of text or a number).

Function parameters that have a = with a value after them are optional. If you leave them out, the default value shown is used automatically.

Function parameters without a = are usually required. A few optional parameters have no default value, so the signature shows them without a = as well. To check whether a parameter is required, look at the parameter list below the signature. Each parameter is marked as Required or Optional.

The most common optional parameter without a default value is default. The default parameter sets the value a function returns when the function can’t produce a result, for example, when float gets text that isn’t a number. If you leave out default, there is no fallback value, so most functions raise an error and the template fails. The parameter list of each function says what happens. If you set default, the function returns your value instead.

How to read a signature

Here is the signature of the round filter as an example:

round(
    value: Any,
    precision: int = 0,
    method: str = "common",
    default: Any,
) -> float | int | Any
  • round is the name of the function.
  • Between the parentheses are the parameters. Each parameter has a name, followed by a colon and the type of value the parameter expects. The type only tells you what kind of value to pass. For default: Any, you pass a value of any type, such as 0 or "unknown", not the word Any.
  • = 0 and = "common" are default values. You can leave out precision and method, and round uses these default values.
  • default has no =, but the parameter list marks default as optional. If you leave out default and round gets a value that isn’t a number, round raises an error.
  • -> shows the type of value the function returns.
  • Inside a signature, | means “or”. This function returns a decimal number, a whole number, or the value you passed as default.

round is a filter, so the first parameter, value, is the value before the |. For example, {{ 3.14159 | round(2) }} returns 3.14.

The types you’ll see most often:

  • str: text, such as "hello"
  • int: a whole number, such as 5
  • float: a decimal number, such as 3.14
  • bool: true or false
  • list: a list of values, such as [1, 2, 3]. list[str] is a list of texts.
  • dict: a set of keys and values, such as {"name": "Kitchen"}
  • datetime and timedelta: a date and time, and a duration. For details, refer to Dates and times.
  • None: no value
  • Any: any type of value

Some signatures use special forms:

  • *args means you can pass any number of values, separated by commas. For example, average(1, 2, 3).
  • value | name(...) means the function is a filter. The value before the | is passed to the filter as its first parameter. Some filter signatures, like the round example, show this value as the first parameter between the parentheses instead.
groupby(
    value: list,
    attribute: str,
    default: Any = None,
    case_sensitive: bool = False,
) -> list[tuple]

Function parameters

The following parameters can be provided to this filter.

value list Required

The list of items to group.

attribute string Required

The attribute to group by. Supports dotted notation for nested attributes (for example, attributes.device_class).

default any (Optional)

The value to group by for items that don’t have the attribute. If not provided, an item without the attribute causes an error.

case_sensitive boolean (Optional, default: false)

Whether values that only differ in uppercase and lowercase, such as On and on, go in separate groups. By default, they go in the same group.

Grouping with dotted attributes

Use dotted notation to group by nested attributes.

TemplateA template is an automation definition that can include variables for the action or data from the trigger values. This allows automations to generate dynamic actions. [Learn more]: Group sensors by device class 
{% for device_class, entities in expand("sensor.home_sensors")
  | groupby("attributes.device_class") %}
  {{ device_class }}: {{ entities | length }} sensors
{% endfor %}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
humidity: 3 sensors
temperature: 5 sensors

Default value for missing attributes

Use the default parameter to include items that lack the grouping attribute. Sensors without a device class don’t have the device_class attribute, so they go in the none group.

TemplateA template is an automation definition that can include variables for the action or data from the trigger values. This allows automations to generate dynamic actions. [Learn more] 
{% for device_class, sensors in expand("sensor.home_sensors")
  | groupby("attributes.device_class", default="none") %}
  {{ device_class }}: {{ sensors | map(attribute="entity_id") | join(", ") }}
{% endfor %}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
humidity: sensor.bathroom_humidity
none: sensor.last_notification
temperature: sensor.kitchen_temperature, sensor.living_room_temperature

Good to know

  • You don’t need to sort the items first. The filter sorts them by the grouping attribute, so the groups come out in that order.
  • If an item doesn’t have the attribute and you don’t set a default, the template fails with an error.
  • By default, grouping ignores uppercase and lowercase. On and on end up in the same group, and the group is named after the value of its first item. To keep them apart, set case_sensitive=true.
  • Returns a list of (grouper, items) tuples, which you unpack in a for loop.

Try it yourself

Ready to test this? Open Settings > Tools > Template, paste the example into the Template editor, and watch the result update on the right. Edit the values to see how the function adapts to your own 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].

More examples

Real scenarios where this function comes up in automations and templates. Copy any example and adapt it to your setup.

Group entities by state

Group all entities in a group by their current state value.

TemplateA template is an automation definition that can include variables for the action or data from the trigger values. This allows automations to generate dynamic actions. [Learn more] 
{% for state, entities in expand("light.home_lights") | groupby("state") %}
  {{ state | upper }}: {{ entities | map(attribute="name") | join(", ") }}
{% endfor %}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
OFF: Bedroom light, Garage light
ON: Kitchen light, Living room light

Count entities per group

Show a summary of how many entities are in each group.

TemplateA template is an automation definition that can include variables for the action or data from the trigger values. This allows automations to generate dynamic actions. [Learn more] 
{% for state, entities in expand("light.home_lights") | groupby("state") %}
  {{ entities | length }} light(s) are {{ state }}
{% endfor %}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
2 light(s) are off
2 light(s) are on

Group sensors by unit and find averages

Group temperature sensors by their unit of measurement and calculate the average for each unit. This is useful if some of your sensors report in °C and others in °F.

TemplateA template is an automation definition that can include variables for the action or data from the trigger values. This allows automations to generate dynamic actions. [Learn more] 
{% for unit, sensors in expand("sensor.temperature_sensors")
  | groupby("attributes.unit_of_measurement") %}
  {{ unit }}: {{ sensors | map(attribute="state") | map("float")
     | average | round(1) }}
{% endfor %}
Result (stringA piece of text, like a name, message, or entity ID. In templates, wrap strings in quotes, like "living_room" or "lights are on".) 
°C: 21.1
°F: 70.3

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with your template and expected result, or share on our subreddit /r/homeassistant.

Tip

AI assistants like ChatGPT or Claude can also explain or fix templates when you describe what you want in plain language.

Related template functions

These functions work well alongside this one: