Home ▸ Template functions

Filter items by test: select

The select filter iterates over a list and keeps only the items that pass a given test. Each item is tested individually, and only those for which the test returns true are included in the result.

This is one of the most powerful filters for working with lists of values in Home Assistant templates. You can use it to filter numeric values (keep only those above a threshold), filter strings (keep only those matching a pattern), or apply any of the built-in tests. It works on the items themselves; to filter by an attribute of each item, use selectattr instead. The select filter is commonly combined with map to first extract values, then filter them.

Usage

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

As a filter

{{ [1, 2, 3, 4, 5] | select("greaterthan", 3) | list }}

Result (list)

[4, 5]

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.

select(
    value: list,
    *args: str,
) -> iterable

Function parameters

The following parameters can be provided to this filter.

value list Required

The list of items to filter.

args string (Optional)

The test name as a string, optionally followed by arguments for the test. If no test is provided, items are tested for truthiness. Common tests include equalto, greaterthan, lessthan, string, number, contains, is_state, and is_number.

Filter by truthiness

When no test is specified, select keeps items that are truthy (not false, 0, none, or empty).

Template

{{ [0, 1, "", "hello", none, true] | select | list }}

Result (list)

[1, 'hello', True]

Common tests

Greater than / less than

Template: Temperatures above 20

{{
  [18.5, 21.3, 25.0, 19.8, 22.1]
  | select("greaterthan", 20)
  | list
}}

Result (list)

[21.3, 25.0, 22.1]

Equal to

Template: Keep only "on" values

{{ ["on", "off", "on", "off", "on"] | select("equalto", "on") | list }}

Result (list)

['on', 'on', 'on']

Contains

Template: Weather conditions with rain

{{
  ["sunny", "light rain", "cloudy", "heavy rain"]
  | select("contains", "rain")
  | list
}}

Result (list)

['light rain', 'heavy rain']

Good to know

Returns an iterable, not a list. Add | list before using it with length, first, or looping twice.
Without a test, truthy items are kept. Zero, empty string, and None are dropped because they are falsy.
To filter by an attribute of each item, use selectattr instead.

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.

Filter numeric values from sensor data

After extracting state values, keep only those that are valid numbers.

Template

{{
  expand("sensor.temperature_sensors")
  | map(attribute="state")
  | select("is_number")
  | map("float")
  | list
}}

Result (list)

[21.5, 19.8, 22.3]

Find temperatures above a threshold

Extract values, convert to float, and filter for those above a target.

Template

{{
  expand("sensor.temperature_sensors")
  | map(attribute="state")
  | map("float")
  | select("greaterthan", 21)
  | list
}}

Result (list)

[21.5, 22.3]

Count values matching a condition

Combine select with list and length to count matching items.

Template: Number of open doors

{{
  expand("binary_sensor.home_doors")
  | map(attribute="state")
  | select("equalto", "on")
  | list
  | length
}}

Result (integer)

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:

Remove items by test: reject - Filters a list, removing items that pass a given test. The opposite of select.
Filter items by attribute test: selectattr - Filters a list, keeping only items where a specified attribute passes a test.
Remove items by attribute test: rejectattr - Filters a list, removing items where a specified attribute passes a test. The opposite of selectattr.
Transform list items: map - Applies a filter to each item or extracts an attribute from each item in a list.

Help us improve our documentation

Was this page helpful?

Suggest an edit to this page, or provide/view feedback for this page.