---
title: useBeforeUnload
---

# useBeforeUnload

<!--
⚠️ ⚠️ IMPORTANT ⚠️ ⚠️ 

Thank you for helping improve our documentation!

This file is auto-generated from the JSDoc comments in the source
code, so please edit the JSDoc comments in the file below and this
file will be re-generated once those changes are merged.

https://github.com/remix-run/react-router/blob/main/packages/react-router/lib/dom/lib.tsx
-->

[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.