Q: What is the HTML <dialog> element?

The <dialog> element is a native HTML element that represents a modal or non-modal dialog box. It was introduced in HTML5 and is now supported by all modern browsers. It provides built-in accessibility features, focus trapping, and a ::backdrop pseudo-element for overlay styling – all without any JavaScript library.

Q: What's the difference between showModal() and show()?

showModal() opens the dialog as a modal – it creates a backdrop overlay, traps focus, prevents interaction with the rest of the page, and allows ESC to close. show() opens it as a non-modal dialog – no backdrop, no focus trapping, and it behaves more like a positioned popover. Use showModal() for confirmations, alerts, and forms; use show() for optional info panels.

Q: How do I customize the backdrop overlay?

Use the ::backdrop CSS pseudo-element. For example: dialog::backdrop { background: rgba(0,0,0,0.6); backdrop-filter: blur(4px); }. You can set any background color, gradient, or even add a blur effect. Note that ::backdrop only works with showModal(), not show().

Q: Can I animate the dialog opening and closing?

Yes! For opening, use CSS @keyframes on dialog[open]. For closing, it's trickier because the dialog's display changes immediately. The best approach: add a CSS class (e.g., .closing) that triggers an exit animation, listen for the animationend event, then call dialog.close() and remove the class. This generator produces code with this pattern built-in.

Q: How does the ESC key interact with dialogs?

When opened via showModal(), pressing ESC will automatically close the dialog and dispatch a cancel event. You can prevent this by calling event.preventDefault() in the cancel event handler. Dialogs opened with show() do not respond to ESC by default.

Q: What is the browser compatibility of <dialog>?

The <dialog> element is supported in Chrome 37+, Edge 79+, Firefox 98+, Safari 15.4+, and Opera 24+. As of 2024, global support exceeds 96%. For older browsers, a polyfill is available. Safari added full showModal() support in version 15.4 (March 2022).

Q: Can I click the backdrop to close the dialog?

Yes! Add a click listener on the dialog itself. When the user clicks the backdrop (which is technically outside the dialog's content area), event.target === dialog will be true. Then call dialog.close(). This is a common UX pattern implemented in the generated code.

Q: Are native dialogs accessible?

Yes, native <dialog> elements have excellent built-in accessibility: they automatically manage focus (trap it within the modal), the backdrop prevents interaction with background content, screen readers announce them correctly, and semantic roles are applied automatically. This is a major advantage over custom div-based modals.

Q: How do I get a return value from a dialog?

Use dialog.close(returnValue) to close the dialog with a value, then read dialog.returnValue. For example, a confirm button can call dialog.close('confirmed'), and the caller can check dialog.returnValue === 'confirmed'. This is useful for confirmation dialogs and form modals.