## Configuration check

{% if page.installation == "os" %}

After changing configuration or automation files, check if the configuration is valid before restarting Home Assistant Core.

### Running a configuration check from the UI

1. Go to {% my profile title="your user profile" %} and enable **Advanced Mode**.
2. Go to {% my server_controls title="**Developer tools** > **YAML**" %} and in the **Configuration validation** section, select the **Check configuration** button.
   - This is to make sure there are no syntax errors before restarting Home Assistant.
   - It checks for valid {% term YAML %} and valid config structures.
3. If you need to do a more comprehensive configuration check, [run the check from the CLI](#to-run-a-configuration-check-from-the-cli).

### Running a configuration check from the CLI

Use the following command to check if the configuration is valid. The command line configuration check validates the {% term YAML %} files and checks for valid config structures, as well as some other elements.

```bash
ha core check
```

{% elsif page.installation == "container" %}

After changing configuration files, check if the configuration is valid before restarting Home Assistant Core.

_If your container name is something other than `homeassistant`, change that part in the examples below._

Run the full check:

```bash
docker exec homeassistant python -m homeassistant --script check_config --config /config
```

Listing all loaded files:

```bash
docker exec homeassistant python -m homeassistant --script check_config --files
```

Viewing an integration’s configuration ([`light`](/integrations/light) in this example):

```bash
docker exec homeassistant python -m homeassistant --script check_config --info light
```

Or all integrations’ configuration

```bash
docker exec homeassistant python -m homeassistant --script check_config --info all
```

You can get help from the command line using:

```bash
docker exec homeassistant python -m homeassistant --script check_config --help
```

{% endif %}