Id of the active tab. There can only be one active tab. If you change this property, you will need to call .refresh() method to update the tab. If you need to simulate a click on a tab see .doClick(). Active tab can be defined during object creation: let tabs = new w2tabs({ name: 'tabs', active: 'tab1', tabs: [ { id: 'tab1', text: 'Tab 1' }, { id: 'tab2', text: 'Tab 2' }, { id: 'tab3', text: 'Tab 3' }, { id: 'tab4', text: 'Tab 4' } ] }); Or during run-time: w2ui.tabs.active = 'tab2'; w2ui.tabs.refresh();