---
title: useBeforeUnload
---

# useBeforeUnload

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[MODES: framework, data, declarative]

## Summary

[Reference Documentation ↗](https://api.reactrouter.com/v7/functions/react-router.useBeforeUnload.html)

Set up a callback to be fired on [Window's `beforeunload` event](https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event).

## Signature

```tsx
function useBeforeUnload(
  callback: (event: BeforeUnloadEvent) => any,
  options?: {
    capture?: boolean;
  },
): void
```

## Params

### callback

The callback to be called when the [`beforeunload` event](https://developer.mozilla.org/en-US/docs/Web/API/Window/beforeunload_event) is fired.

### options.capture

If `true`, the event will be captured during the capture phase. Defaults to `false`.

## Returns

No return value.