Element: beforescriptexecute event

Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

Warning: This event was a proposal in an early version of the specification. Do not rely on it.

The beforescriptexecute event is fired when a script is about to be executed. Cancelling the event prevents the script from executing.

It is a proprietary event specific to Gecko (Firefox).

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js
addEventListener("beforescriptexecute", (event) => { })

onbeforescriptexecute = (event) => { }

Event type

A generic Event.

Specifications

Not part of any specification.

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
beforescriptexecute event
Deprecated Non-standard
Chrome – No support
Chrome
footnote No support
Edge – No support
Edge
footnote No support
Firefox – No support
Firefox 2 – 143 (Release date: 2006-10-24)
footnote Removed in 144 and later
Opera – No support
Opera
footnote No support
Safari – No support
Safari
footnote No support
Chrome Android – No support
Chrome Android
footnote No support
Firefox for Android – No support
Firefox for Android 4 – 143 (Release date: 2011-03-29)
footnote Removed in 144 and later
Opera Android – No support
Opera Android
footnote No support
Safari on iOS – No support
Safari on iOS
footnote No support
Samsung Internet – No support
Samsung Internet
footnote No support
WebView Android – No support
WebView Android
footnote No support
WebView on iOS – No support
WebView on iOS
footnote No support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
Non-standard. Check cross-browser support before using.
Deprecated. Not for use in new websites.

See also