# useViewport

**Kind:** Function

Returns the current `Viewport` object and updates whenever the viewport size, constraints,
or fullscreen status changes.

```js
import {useViewport} from '@airtable/blocks/ui';

function ViewportSize() {
     const viewport = useViewport();

     const toggleFullscreen = () => {
         if (viewport.isFullscreen) {
             viewport.exitFullscreen();
         } else {
             viewport.enterFullscreenIfPossible();
         }
     };

     return (
         <Fragment>
             <button onClick={toggleFullscreen}>Toggle fullscreen</button>

             viewport size: {viewport.size.width}x{viewport.size.height}
         </Fragment>
     );
}
```

**Returns:** `Viewport`