The Window.confirm() method displays a modal dialog with an optional message and two buttons, OK and Cancel.


result = window.confirm(message);
  • message is the optional string to be displayed in the dialog.
  • result is a boolean value indicating whether OK or Cancel was selected (true means OK).


if (window.confirm("Do you really want to leave?")) {"exit.html", "Thanks for Visiting!");


firefox confirm


The following text is shared between this article, DOM:window.prompt and DOM:window.alert Dialog boxes are modal windows - they prevent the user from accessing the rest of the program's interface until the dialog box is closed. For this reason, you should not overuse any function that creates a dialog box (or modal window). And regardless, there are very good reasons to avoid using dialog boxes for confirmation.

Starting with Chrome 46.0 this method is blocked inside an <iframe> unless it sandbox attribute has the value allow-modal.

The argument is optional and not required by the spec.


Specification Status Comment
HTML Living Standard
The definition of 'confirm()' in that specification.
Living Standard  

See also