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.

Mozilla Chrome users (e.g. Firefox extensions) should use methods of nsIPromptService instead.

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
HTML5 Web application
The definition of 'confirm()' in that specification.
Unknown Initial definition.

See also