files/en-us/web/api/window/confirm/index.md
{{ApiRef("Window")}}
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.
confirm()
confirm(message)
message {{optional_inline}}
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.
The following example shows how to check the returned value of a confirmation dialog. When the user clicks the OK button, we call {{domxref("window.open()")}}, and if the user clicks Cancel, we print some text to a {{htmlelement("pre")}} element.
<button id="windowButton">Open new tab</button>
<pre id="log"></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!";
}
});
{{EmbedLiveSample('confirm', , , , , , , 'allow-modals allow-popups')}}
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 {{HTMLElement("dialog")}} element can be used for confirmations.
{{Specifications}}
{{Compat}}