# The “dialog” element is not supported in all browsers. Please be sure to test, and consider using a polyfill.

> Canonical HTML version: https://rocketvalidator.com/html-validation/the-dialog-element-is-not-supported-in-all-browsers-please-be-sure-to-test-and-consider-using-a-polyfill
> Attribution: Rocket Validator (https://rocketvalidator.com)
> License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

The `<dialog>` element triggers an informational warning from the W3C validator, not an error. The markup is valid HTML, and no code change is needed to resolve this message.

The `<dialog>` element is a native HTML element for modal and non-modal dialog boxes. It was part of the HTML specification for years before all major browsers implemented it. As of 2022, all major browsers (Chrome, Firefox, Safari, and Edge) support `<dialog>` natively. The W3C validator warning is outdated for most practical purposes, since browser support is now widespread.

The `<dialog>` element provides built-in features that are difficult to replicate with custom markup: a `showModal()` method that creates a top-layer modal with a backdrop, automatic focus trapping, and `Esc` key dismissal. It also exposes the correct ARIA role (`dialog`) by default, which improves accessibility without extra attributes.

If you still need to support older browsers (such as Internet Explorer or pre-2022 Safari), you can include the [dialog-polyfill](https://github.com/GoogleChrome/dialog-polyfill) library. Otherwise, the warning can be safely ignored.

## HTML example

```html
<dialog id="confirm">
  <form method="dialog">
    <p>Are you sure?</p>
    <button value="no">Cancel</button>
    <button value="yes">Confirm</button>
  </form>
</dialog>

<button onclick="document.getElementById('confirm').showModal()">
  Open dialog
</button>
```

Using `method="dialog"` on the form allows the dialog to close automatically when a button inside it is clicked, with the button's `value` available through the dialog's `returnValue` property.