Window: confirm() method

Baseline Widely 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

js
confirm()
confirm(message)

Parameters

message Optional

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 always false.

Examples

Confirming before an action

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

html
<button id="windowButton">Open new tab</button>
<pre id="log"></pre>
js
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.

Specifications

Specification
HTML
# dom-confirm-dev

Browser compatibility

See also