api.Window.beforeunload_event.event_returnvalue_activation

Spec

MDN URL

Status

On the standards track: Yes

Is Experimental: No

Is Deprecated: Yes

Browser Support

In Chrome version 119 on 2023-10-31 Note: Before Chrome 119, an empty string incorrectly activated the confirmation dialog.

In Chrome Android version 119 on 2023-10-31 Note: Before Chrome Android 119, an empty string incorrectly activated the confirmation dialog.

Not in Deno

In Edge version 119 on 2023-11-02 Note: Before Edge 119, an empty string incorrectly activated the confirmation dialog.

In Firefox version 6 on 2011-08-16

In Firefox for Android version 6 on 2011-08-16

In Internet Explorer version 9 on 2011-03-14

In Quest Browser version 5.0 on undefined Note: Before Quest Browser false, an empty string incorrectly activated the confirmation dialog.

In Opera version 105 on 2023-11-14 Note: Before Opera 105, an empty string incorrectly activated the confirmation dialog.

In Opera Android version 79 on 2023-12-06 Note: Before Opera Android 79, an empty string incorrectly activated the confirmation dialog.

In Safari version 8 on 2014-10-16

Not in Safari on iOS

In Samsung Internet version 25.0 on 2024-04-24 Note: Before Samsung Internet 25.0, an empty string incorrectly activated the confirmation dialog.

In WebView Android version 119 on 2023-10-31 Note: Before WebView Android 119, an empty string incorrectly activated the confirmation dialog.

Not in WebView on iOS