HTMLDialogElement: showModal() method

The showModal() method of the HTMLDialogElement interface displays the dialog as a modal dialog, over the top of any other dialogs or elements that might be visible.

A modal dialog displays in the top layer, along with a ::backdrop pseudo-element. Elements inside the same document as the dialog, except the dialog and its descendants, become inert (as if the inert attribute is specified). Only the containing document becomes blocked; if the dialog is rendered inside an iframe, the rest of the page remains interactive.

Syntax

js
showModal()

Parameters

None.

Return value

None (undefined).

Exceptions

InvalidStateError DOMException

Thrown if the dialog is already open and non-modal (i.e., if the dialog has already been opened with HTMLDialogElement.show()).

Examples

undefined

Basic usage

The following example shows a simple button that, when clicked, opens a <dialog> using the showModal() method.

When the dialog is open, you cannot interact with the rest of the page, including clicking the Click me button that would otherwise trigger an alert.

You can click the Close dialog button to close the dialog (via the HTMLDialogElement.close() method).

HTML

html
<dialog id="dialog">
  <button type="button" id="close">Close dialog</button>
</dialog>

<p><button id="open">Open dialog</button></p>
<p><button id="alert">Trigger alert</button></p>

JavaScript

js
const dialog = document.getElementById("dialog");
const openButton = document.getElementById("open");
const closeButton = document.getElementById("close");
const alertButton = document.getElementById("alert");

// Open button opens a modal dialog
openButton.addEventListener("click", () => {
  dialog.showModal();
});

// Alert button triggers an alert
alertButton.addEventListener("click", () => {
  alert("you clicked me!");
});

// Close button closes the dialog box
closeButton.addEventListener("click", () => {
  dialog.close();
});

Result

Specifications

See also