Web/API/Event/cancelable

The cancelable read-only property of the Event interface indicates whether the event can be canceled, and therefore prevented as if the event never happened. If the event is not cancelable, then its cancelable property will be false and the event listener cannot stop the event from occurring.

Event listeners that handle multiple kinds of events may want to check cancelable before invoking their preventDefault() methods.

Most browser-native events that can be canceled are the ones that result from the user interacting with the page. Canceling the click, scroll, or beforeunload events would prevent the user from clicking on something, scrolling the page, or navigating away from the page, respectively.

Custom events created by other JavaScript code control if they can be canceled when they are created.

Syntax

bool = event.cancelable;

Value

The result is a Boolean, which is true if the event can be canceled.

Example

For example, browser vendors are proposing that the wheel event can only be canceled the first time the listener is called — any following wheel events cannot be canceled.

function preventScrollWheel(event) {
  if (typeof event.cancelable !== 'boolean' || event.cancelable) {
    // The event can be canceled, so we do so.
    event.preventDefault();
  } else {
    // The event cannot be canceled, so it is not safe
    // to call preventDefault() on it.
    console.warn(`The following event couldn't be canceled:`);
    console.dir(event);
  }
}

document.addEventListener('wheel', preventScrollWheel);

Notes

Whether an event can be canceled or not is something that's determined when that event is initialized.

To cancel an event, call the preventDefault() method on the event. This keeps the implementation from executing the default action that is associated with the event.

Specifications

Specification	Status	Comment
DOMThe definition of 'Event.cancelable' in that specification.	Living Standard
Document Object Model (DOM) Level 2 Events SpecificationThe definition of 'Event.cancelable' in that specification.	Obsolete	Initial definition.

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
cancelable	Chrome Full support Yes	Edge Full support 12	Firefox Full support Yes	IE ?	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support Yes	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes

Legend

Full support  

Full support

Compatibility unknown  

Compatibility unknown

Event.cancelable by Mozilla Contributors is licensed under CC-BY-SA 2.5.