The ariaSetSize property of the Element interface reflects the value of the aria-setsize attribute, which defines the number of items in the current set of listitems or treeitems.


A string containing an integer.


In this example the aria-setsize attribute on the element with an ID of tab-id is set to "3", to inform a device that there are currently 3 tabs in the group. Using ariaSetSize we update the value to "4".

<button role="tab" aria-selected="true" aria-setsize="3" aria-controls="tabpanel-id" id="tab-id">Tab label</button>
let el = document.getElementById('tab-id');
console.log(el.ariaSetSize); // 3
el.ariaSetSize = "4";
console.log(el.ariaSetSize); // 4


Accessible Rich Internet Applications (WAI-ARIA)
# dom-ariamixin-ariasetsize

Browser compatibility

BCD tables only load in the browser

See also