Window: confirm() method

BaselineWidely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

window.confirm() instructs the browser to display a dialog with an optional message, and to wait until the user either confirms or cancels the dialog.

Under some conditions — for example, when the user switches tabs — the browser may not actually display a dialog, or may not wait for the user to confirm or cancel the dialog.

Syntax

confirm()confirm(message)

Parameters

messageOptional: A string you want to display in the confirmation dialog.

Return value

A boolean indicating whether OK (true) or Cancel (false) was selected.If a browser is ignoring in-page dialogs, then the returned value is alwaysfalse.

The following example shows how to check the returned value of a confirmation dialog.When the user clicks the OK button, we callwindow.open(), and if the user clicks Cancel, we print some text to a<pre> element.

html

<button>Open new tab</button><pre></pre>

const windowButton = document.querySelector("#windowButton");const log = document.querySelector("#log");windowButton.addEventListener("click", () => {  if (window.confirm("Do you want to open in new tab?")) {    window.open("https://developer.mozilla.org/en-US/docs/Web/API/Window/open");  } else {    log.innerText = "Glad you're staying!";  }});

Notes

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 a modal window.Alternatively, a<dialog> element can be used for confirmations.