SHA1 hash: sha1

The sha1 template function calculates the SHA1 hash of a string and returns the result as a hexadecimal string. SHA1 produces a 160-bit (40-character hex) hash value from any input string.

This is useful when you need a longer hash than MD5 for generating identifiers or checksums. SHA1 provides a 40-character hex output compared to MD5’s 32 characters. Like MD5, it is not recommended for security-sensitive purposes. For cryptographic use cases, prefer sha256 or sha512.

Usage

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

{{ sha1("Hello, World!") }}

0a0a9f2a6772942557ab5355d76af442f8f65e01

{{ "Hello, World!" | sha1 }}

0a0a9f2a6772942557ab5355d76af442f8f65e01

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.

sha1(
    value: str,
) -> str

Function parameters

The following parameters can be provided to this function.

Good to know

• SHA1 is no longer considered secure for cryptographic use. Prefer sha256 or sha512 for anything sensitive.
• The result is always a 40-character lowercase hexadecimal string.

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.

Generate a unique identifier

Create a consistent identifier from a combination of entity ID and date.

{{ sha1("sensor.temperature_" ~ now().date() | string) }}

b2e5f8a1c3d4e6f7a8b9c0d1e2f3a4b5c6d7e8f9

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:

• MD5 hash: md5 - Calculates the MD5 hash of a string.

• SHA256 hash: sha256 - Calculates the SHA256 hash of a string.

• SHA512 hash: sha512 - Calculates the SHA512 hash of a string.