Web/API/WindowEventHandlers/onbeforeprint

The onbeforeprint property of the WindowEventHandlers mixin is the EventHandler for processing beforeprint events for the current window. These events are raised before the print dialog window is opened.

The beforeprint and afterprint events allow pages to change their content before printing starts (perhaps to remove a banner, for example) and then revert those changes after printing has completed. In general, you should prefer the use of an @media print CSS at-rule, but it may be necessary to use these events in some cases.

Syntax

window.addEventListener("beforeprint", function(event) { ... });
window.onbeforeprint = function(event) { ... };

Polyfill

Safari does not implement these events, but you can create an equivalent result to the beforeprint event with window.matchMedia('print').

var mediaQueryList = window.matchMedia('print');
mediaQueryList.addListener(function(mql) {
  if(mql.matches) {
    console.log('webkit equivalent of onbeforeprint');
  }
});

Specification

Specification	Status	Comment
HTML Living StandardThe definition of 'onbeforeprint' in that specification.	Living Standard

Browser compatibility

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
`onbeforeprint`	Chrome Full support 63	Edge Full support 12	Firefox Full support 6	IE Full support Yes	Opera Full support 50	Safari Full support 13	WebView Android Full support 63	Chrome Android Full support 63	Firefox Android ?	Opera Android Full support 46	Safari iOS Full support 13	Samsung Internet Android Full support 8.0

Legend

Full support: Full support
Compatibility unknown: Compatibility unknown