Capitalize first character: capitalize

The capitalize filter converts the first character of a string to uppercase and makes all remaining characters lowercase. This is useful when you want to ensure a consistent sentence-case format for display purposes. For example, you might want to normalize a sensorSensors return information about a thing, for instance the level of water in a tank. [Learn more] state like OPEN or closed to a cleaner Open or Closed format for use in notifications or dashboard cards.

Usage

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

{{ "hello WORLD" | capitalize }}

Hello world

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.

capitalize(
    value: str,
) -> str

Function parameters

The following parameters can be provided to this function.

Good to know

• Only the very first character is uppercased. The rest of the string is always lowercased, even if it contained capitals before.
• Multi-word values become sentence case, not title case. Use title when you want every word capitalized.

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.

Normalize a sensor state for display

Clean up an entity state so it looks presentable in a notification.

{{ "The door is " ~ states("binary_sensor.front_door") | capitalize }}

The door is Off

Format a name from user input

Normalize a name entered through a text helper to sentence case.

{{ states("input_text.greeting") | capitalize }}

Hello world

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 lowercase: lower - Converts all characters in a string to lowercase.

• Convert to uppercase: upper - Converts all characters in a string to uppercase.

• Convert to title case: title - Converts a string to title case, capitalizing the first letter of each word.