# useViewportAutoFitScale

Source: https://sdk.pdf.net/docs/v1/reference/useViewportAutoFitScale



Fits the pages into the viewport once per loaded document: the usual "open at a sensible zoom" behavior, with no wiring.

```ts
useViewportAutoFitScale(target)
```

`target` is `'width'` or `'height'`: which viewport dimension the pages are fitted into. The fit is applied when a document loads; it doesn't re-apply on later viewport resizes or manual zooming, so the user's zoom choice is respected.

## Example [#example]

```tsx
import { useViewportAutoFitScale, Viewport } from '@sdk-pdf/react'

function PdfApplication() {
  useViewportAutoFitScale('width')

  return (
    <div style={{ height: '100vh' }}>
      {/* Throws DocumentNotLoadedError when no document is loaded, since there is nothing
          to show. Render it only when the load state is 'ready'. */}
      <Viewport />
    </div>
  )
}
```