# NEL header



The HTTP **`NEL`** [response header](https://developer.mozilla.org/en-US/docs/Glossary/response%20header) is used to configure network request logging.

<table class="properties">
  <tbody>
    <tr>
      <th scope="row">Header type</th>
      <td>[Response header](https://developer.mozilla.org/en-US/docs/Glossary/Response%20header)</td>
    </tr>
  </tbody>
</table>

## Syntax

```http
NEL: { "report_to": "name_of_reporting_group", "max_age": 12345, "include_subdomains": false, "success_fraction": 0.0, "failure_fraction": 1.0 }
```

## Specifications

## Browser compatibility

## See also

- [Network Error Logging (NEL) explainer](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Network_Error_Logging)