HTMLDialogElement: open property

Baseline 2022

Newly available

Since March 2022, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The open property of the HTMLDialogElement interface is a boolean value reflecting the open HTML attribute, indicating whether the <dialog> is available for interaction.


A boolean value representing the state of the open HTML attribute. true means it is set, and therefore the dialog is shown. false means it not set, and therefore the dialog is not shown.

The property is not read only — it is possible to set the value to programmatically show or hide the dialog.


The following example shows a simple button that, when clicked, opens a <dialog> containing a form via the showModal() method. From there you can click the Cancel button to close the dialog (via the HTMLDialogElement.close() method), or submit the form via the submit button.

<!-- Simple pop-up dialog box -->
<dialog id="dialog">
  <form method="dialog">
    <button type="submit">Close</button>

  <button id="openDialog">Open Dialog</button>
<p id="dialogStatus"></p>

  (() => {
    const openDialog = document.getElementById("openDialog");
    const dialog = document.getElementById("dialog");
    const text = document.getElementById("dialogStatus");

    function openCheck(dialog) {
      if ( {
        text.innerText = "Dialog open";
      } else {
        text.innerText = "Dialog closed";

    // Update button opens a modal dialog
    openDialog.addEventListener("click", () => {

    dialog.addEventListener("close", () => {



HTML Standard
# dom-dialog-open

Browser compatibility

BCD tables only load in the browser

See also

  • The HTML element implementing this interface: <dialog>.