Test if boolean: boolean

The boolean test checks whether a value is a boolean (true or false). It returns true if the value is of boolean type and false for any other type, including strings like true or integers like 1.

This is useful when you need to verify the type of a value before processing it. In Home Assistant, 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] states are always strings, but attributes can be actual booleans. If you need to distinguish between a real boolean and a string that looks like one, this test lets you check the actual type.

Usage

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

{% if true is boolean %}
  It is a boolean
{% endif %}

It is a boolean

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 default are required.

boolean(
    value: Any,
) -> bool

Function parameters

The following parameters can be provided to this test.

Good to know

• Only the actual boolean values true and false pass this test. Strings like "true" and integers like 1 do not.
• Entity states are always strings, so this test will never succeed on a raw states(...) result.

Try it yourself

Ready to test this? Open Developer 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.

Distinguish boolean from string

Check whether a value is actually a boolean and not a string representation.

{{ true is boolean }}
{{ "true" is boolean }}

true
false

Validate an attribute type

Verify that an 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] attribute is a real boolean before using it directly.

{% set val = state_attr("switch.device", "is_locked") %}
{% if val is boolean %}
  Lock state: {{ val }}
{% else %}
  Unexpected type
{% endif %}

Lock state: True

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.

Related template functions

These functions work well alongside this one:

• Convert to boolean: bool - Converts a value to a boolean (true/false), with an optional default if conversion fails.

• Get the type of a value: typeof - Returns the type name of a value as a string.