> For the complete documentation index, see [llms.txt](https://docs.overleaf.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.overleaf.com/on-premises/configuration/overleaf-toolkit/branding.md).

# Branding

## Header

In this section, we'll cover how to personalize key elements of your on-premises instance. You can customize the site title, navigation links, header, footer, and logo according to your preferences.

## Site title

The navigation bar title can be customized with the `OVERLEAF_NAV_TITLE` environment variable, this text is used in the top left corner of navigation if no logo is set.

```
# add to config/variables.env
OVERLEAF_NAV_TITLE=Our Overleaf Instance
```

## Logo

You can add a custom logo by setting the environment variable `OVERLEAF_HEADER_IMAGE_URL`. This value should point to an externally hosted image file.

```
# add to config/variables.env
OVERLEAF_HEADER_IMAGE_URL=https://mysite.somewhere.com/img/logo.png
```

## Header navigation links

Extra navigation items can be added to the navigation header by setting the `OVERLEAF_HEADER_EXTRAS` environment variable to a JSON array of objects. For example:

{% code overflow="wrap" %}

```javascript
[
  {
    "text": "Some link",
    "url": "http://example.com/somelink",
    "class": "subdued",
    "only_when_logged_out": true
  },
  {
    "text": "Help",
    "class": "subdued",
    "dropdown": [
      {
        "text": "Documentation",
        "url": "/learn"
      },
      {
        "text": "Contact Admin",
        "url": "http://example.com/contact"
      }
    ]
  }
]

# add to toolkit/variables.env
OVERLEAF_HEADER_EXTRAS=[{"text":"Some link","url":"http://example.com/somelink","class":"subdued","only_when_logged_out":true},{"text":"Help","class":"subdued","dropdown":[{"text":"Documentation","url":"/learn"},{"text":"Contact Admin","url":"http://example.com/contact"}]}]
```

{% endcode %}

## Footers

It is possible to customize both the left and smaller right footer which is found on pages like `/project` using the environmental variables `OVERLEAF_LEFT_FOOTER` and the smaller `OVERLEAF_RIGHT_FOOTER`

Both expect an array of JSON which will be inserted.

```javascript
[
  {
    "text": "This is an example text footer entry!"
  },
  {
    "text": "This is an example URL footer link!", "url" : "/my-first-link.htm"
  }
]
```

{% hint style="info" %}
When using `text` only, it must **not** contain HTML as the value will be rendered as raw text.
{% endhint %}

This data needs to be valid JSON to work, with quotes escaped when passed through as an environmental variable.

{% code overflow="wrap" %}

```
# add to config/variables.env
OVERLEAF_LEFT_FOOTER=[{"text": "This is an example text footer entry!"}]
OVERLEAF_RIGHT_FOOTER=["text": "This is an example URL footer link!", "url" : "/my-first-link.htm"]
```

{% endcode %}

{% hint style="info" %}
In addition to `text` and `url`, the JSON object also accepts the properties `class` and `label` for additional customization.
{% endhint %}


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