---
title: Document.fullscreen
slug: Web/API/Document/fullscreen
tags:
  - API
  - Deprecated
  - Document
  - Full-screen
  - Fullscreen API
  - Property
  - Read-only
  - Reference
  - fullscreen
  - screen
browser-compat: api.Document.fullscreen
---
{{APIRef("Fullscreen API")}}{{Deprecated_Header}}

The obsolete {{domxref("Document")}} interface's **`fullscreen`** read-only property reports whether or not the document is currently displaying content in full-screen mode.

Although this property is read-only, it will not throw if it is modified (even in strict mode); the setter is a no-operation and it will be ignored.

> **Note:** Since this property is deprecated, you can determine if full-screen mode is active on the document by checking to see if {{DOMxRef("Document.fullscreenElement")}} is not `null`.

## Syntax

    var isFullScreen = document.fullscreen;

### Value

A Boolean value which is `true` if the document is currently displaying an element in full-screen mode; otherwise, the value is `false.`

## Example

This simple function reports whether or not full-screen mode is currently active, using the obsolete `fullscreen` property.

```js
function isDocumentInFullScreenMode() {
  return document.fullscreen;
}
```

This next example, on the other hand, uses the current `fullscreenElement` property to determine the same thing:

```js
function isDocumentInFullScreenMode() {
  return document.fullscreenElement !== null;
}
```

If `fullscreenElement` isn't `null`, this returns `true`, indicating that full-screen mode is in effect.

## Specifications

{{Specifications}}

## Browser compatibility

{{Compat}}

## See also

- [Fullscreen API](/en-US/docs/Web/API/Fullscreen_API)
- [Guide to the Fullscreen API](/en-US/docs/Web/API/Fullscreen_API/Guide)
- {{DOMxRef("Document.fullscreenEnabled")}}
