MDN wants to learn about developers like you:


This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The showModal() method of the HTMLDialogElement interface displays the dialog as a modal, over the top of any other dialogs that might be present. It displays into the top layer, along with a ::backdrop pseudo-element. Interaction outside the dialog is blocked and the content outside it is rendered inert.





Return value



If the dialog is already open (i.e. if the open attribute is already set on the <dialog> element), an InvalidStateError is thrown.


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, containing a form -->
  <dialog id="favDialog">
    <form method="dialog">
        <p><label for="favAnimal">Favorite animal:</label>
        <select id="favAnimal" name="favAnimal">
          <option>Brine shrimp</option>
          <option>Red panda</option>
          <option>Spider monkey</option>
        <button id="cancel" type="reset">Cancel</button>
        <button type="submit">Confirm</button>

    <button id="updateDetails">Update details</button>

    (function() {
      var updateButton = document.getElementById('updateDetails');
      var cancelButton = document.getElementById('cancel');
      var dialog = document.getElementById('favDialog');
      dialog.returnValue = 'favAnimal';

      function openCheck(dialog) {
        if( {
          console.log('Dialog open');
        } else {
          console.log('Dialog closed');

      // Update button opens a modal dialog
      updateButton.addEventListener('click', function() {

      // Form cancel button closes the dialog box
      cancelButton.addEventListener('click', function() {


Note: You can find this example on GitHub as htmldialogelement-basic (see it live also).


Specification Status Comment
WHATWG HTML Living Standard
The definition of 'showModal()' in that specification.
Living Standard  
The definition of 'showModal()' in that specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 37 No support[1] No support 24 No support
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support[1] No support No support No support

[1] Partially implemented since Firefox 53 (the showModal() method currently acts as an alias for show()), but disabled by default; can be enabled via the dom.dialog_element.enabled preference.

See also

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

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, ntim
 Last updated by: chrisdavidmills,