Test if number: number

The number test checks whether a value is a number, meaning either an integer or a float. It returns true for both types and false for anything else, including numeric strings.

This test checks the Python type of the value, not whether a string can be parsed as a number. If you need to check whether a string like 21.5 can be converted to a number, use is_number instead. The number test is useful when you already have a value from a calculation or attribute and want to confirm it is numeric before proceeding.

Usage

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

{% if 42 is number %}
  It is a number
{% endif %}

It is a number

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.

number(
    value: Any,
) -> bool

Function parameters

The following parameters can be provided to this test.

Good to know

• This checks the Python type. Numeric strings like "21.5" do not pass.
• To test whether a value can be parsed as a number, use is_number instead.

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.

Check various types

Both integers and floats pass the number test, but strings do not.

{{ 42 is number }}
{{ 21.5 is number }}
{{ "42" is number }}

true
true
false

Validate attribute values

Check 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 numeric type before doing math.

{% set brightness = state_attr("light.living_room", "brightness") %}
{% if brightness is number %}
  Brightness: {{ (brightness / 255 * 100) | round(0) }}%
{% else %}
  Brightness unknown
{% endif %}

Brightness: 75%

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:

• Test if value is numeric: is_number - Tests whether a value can be converted to a finite number.

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