The ariaLabel property of the Element interface reflects the value of the aria-label attribute, which defines a string value that labels the current element.

A string or null.

In this example the aria-label attribute on the element with an ID of close-button is set to "Close". Using ariaLabel we update the value to "Close dialog".

<button aria-label="Close" id="close-button">X</button>

let el = document.getElementById("close-button");
console.log(el.ariaLabel); // "Close"
el.ariaLabel = "Close dialog";
console.log(el.ariaLabel); // "Close dialog"