The ariaChecked property of the Element interface reflects the value of the aria-checked attribute, which indicates the current "checked" state of checkboxes, radio buttons, and other widgets that have a checked state.

A string with one of the following values:

"true"

The element is checked.

"mixed"

Indicates a mixed mode value for a tri-state checkbox or menuitemcheckbox.

"false"

The element supports being checked but is not currently checked.

"undefined"

The element does not support being checked.

In this example the aria-checked attribute on the element with an ID of checkBoxInput is set to "false" indicating that this input is currently unchecked. Using ariaChecked we update the value to "true".

<span
  role="checkbox"
  id="checkBoxInput"
  aria-checked="false"
  tabindex="0"
  aria-labelledby="chk1-label">
</span>
<label id="chk1-label">Remember my preferences</label>

let el = document.getElementById("checkBoxInput");
console.log(el.ariaChecked); // "false"
el.ariaChecked = "true";
console.log(el.ariaChecked); // "true"

• ARIA: checkbox role